Evidence reference only. Not medical advice, not a dosing guide, and not a recommendation to use any drug.
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Safety signals

130 findings across 17 drug records. Domain pages are descriptive indexes, not advice.

Most represented records

GLP-1 RA class (45)

Semaglutide (36)

Tirzepatide (15)

Retatrutide (9)

Tirzepatide|semaglutide (head-to-head) (8)

Evidence spread

High evidence 23 Moderate evidence 38 Low evidence 44 Very low evidence 25

CagriSema INVESTIGATIONAL
Safety signals Increase
High evidence

In REDEFINE 1, GI AEs common but AE-related discontinuation modest; only a small fraction discontinued specifically for GI events.

Garvey WT, Blüher M, et al. N Engl J Med 2025 (REDEFINE 1) Source
PopulationREDEFINE 1 phase 3, adults with overweight/obesity without T2D
Fundingindustry-Novo Nordisk
Scope limitsconference/abstract-level; magnitude web/secondary-sourced
Comparatorsplacebo; semaglutide 2.4 mg; cagrilintide 2.4 mg
GLP-1 RA class MARKETED
Safety signals Increase
Low evidence

In adults aged 65+ with T2D, GLP-1 RA initiation carried a modestly increased fragility-fracture risk versus other glucose-lowering drugs.

GLP-1 RA and fragility fracture in adults >=65 (cohort, n=46,177), J Clin Endocrinol Meta... Source
PopulationPeer-reviewed primary (women's-health wave)
Fundingacademic / investigator (not separately extracted)
Scope limitsModest and uncertain: observational, active-comparator-confounded (SGLT2i carries its own fracture history), CI lower bound hugs 1.01. SHIFTS the verdict off neutral-reassurance but does NOT establish a fracture excess - not a fracture alarm.
Tirzepatide MARKETED
Safety signals Increase
Low evidence

Real-world data associate tirzepatide with higher osteoporosis/fragility-fracture risk than other GLP-1 RAs - a greatest-weight-loss/dual-agonist signal.

Tirzepatide and osteoporosis/fragility fracture (TriNetX cohort), Diabetes Res Clin Pract... Source
PopulationPeer-reviewed primary (women's-health wave)
Fundingacademic / investigator (not separately extracted)
Scope limitsSHORT 14-month window (too short for fragility-fracture accrual) - hypothesis-generating; coding-based outcomes; weight-loss magnitude the likely mediator; residual confounding. Larger than any RCT signal - do not over-read.
GLP-1 RA class MARKETED
Safety signals Decrease
Moderate evidence

A 2018 Bayesian network meta-analysis of 54 RCTs (49,602 T2D patients) found GLP-1 RAs were associated with decreased fracture risk versus placebo - an independent...

Zhang YS, Weng WY, Xie BC, et al. Glucagon-like peptide-1 receptor agonists and fracture ... Source
Full findingA 2018 Bayesian network meta-analysis of 54 RCTs (49,602 T2D patients) found GLP-1 RAs were associated with decreased fracture risk versus placebo - an independent net-neutral-to-protective fracture pole, separate from the contested anabolic-BMD claim.
PopulationGLP-1 RA fracture network meta-analysis (Zhang et al., Osteoporos Int 2018; 54 RCTs, T2D, PROSPERO CRD42018094433).
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsSCOPE LIMIT: T2D RCTs, PREDATES the high-dose obesity agents (semaglutide 2.4 mg / tirzepatide / retatrutide) - does not speak to rapid-weight-loss bone effects. The 'exenatide ranked safest' sub-claim (and the agent ranking generally) is NOT established - encoded is only the NET protective direction, not the ranking (which rests on sparse fracture events and acknowledged network inconsistency). Provides an INDEPENDENT fracture pole so the net-neutral/protective read no longer rests solely on the contested PMID39985672. Opposes the older-adult-harm pole (C-CLASS-BONE-FRAC-ELDERLY-01) and the unverified SELECT 75+ concern (OQ-BMD-B).
Comparatorsplacebo; other anti-hyperglycaemic drugs
GLP-1 RA class MARKETED
Safety signals Not directional
Low evidence

GLP-1 RA-associated hair loss is markedly female-predominant (men about two-thirds less likely to report it), and more severe with tirzepatide.

GLP-1 RA hair-loss sex-skew (cross-sectional, n=254), J Cosmet Dermatol 2026 Source
PopulationPeer-reviewed primary (women's-health wave)
Fundingacademic / investigator (not separately extracted)
Scope limitsSelf-report, single-country; the female predominance is partly adjusted for the cohort skew. Quantifies the sex-skew beyond the SURMOUNT-1 ~7% vs ~0.5% datum. DEEPENS the alopecia row.
GLP-1 RA class MARKETED
Safety signals Decrease
Low evidence

In a Danish nationwide register of people with type-2 diabetes and hereditary haemochromatosis, each year of GLP-1 receptor agonist exposure was associated with...

Bain SC, Hansen TK et al. Glucose-lowering drugs and serum ferritin in haemochromatosis a... Source
Full findingIn a Danish nationwide register of people with type-2 diabetes and hereditary haemochromatosis, each year of GLP-1 receptor agonist exposure was associated with roughly 30% lower serum ferritin - i.e. GLP-1 RAs are associated with LOWER iron stores, not higher.
PopulationDanish nationwide register (observational cohort), 439 people with hereditary haemochromatosis + type-2 diabetes, 6,529 ferritin measurements 2008-2021; only ~36 GLP-1-exposed contributing ~366 samples.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitspossible confounding by indication
Comparatorsno GLP-1 RA treatment; SGLT-2 inhibitor
GLP-1 RA class MARKETED
Safety signals Increase
Low evidence

In the same register, SGLT-2 inhibitors RAISED serum ferritin, so the headline GLP-1-vs-SGLT-2 gap (~40% at HH year 4) is partly a comparator artefact: part of the...

Bain SC, Hansen TK et al. Glucose-lowering drugs and serum ferritin in haemochromatosis a... Source
Full findingIn the same register, SGLT-2 inhibitors RAISED serum ferritin, so the headline GLP-1-vs-SGLT-2 gap (~40% at HH year 4) is partly a comparator artefact: part of the apparent GLP-1 'lowering' is relative to a drug that raises ferritin, which overstates GLP-1 lowering versus no treatment.
PopulationDanish nationwide register (observational cohort), people with hereditary haemochromatosis + type-2 diabetes; SGLT-2 inhibitor exposure arm.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitspossible confounding by indication
ComparatorsGLP-1 RA; no treatment
GLP-1 RA class MARKETED
Safety signals Not directional
Low evidence

The register study did NOT establish a mechanism for the lower ferritin; the authors flag possible mediation via glycaemic control and body weight, and the model did...

Bain SC, Hansen TK et al. Glucose-lowering drugs and serum ferritin in haemochromatosis a... Source
Full findingThe register study did NOT establish a mechanism for the lower ferritin; the authors flag possible mediation via glycaemic control and body weight, and the model did not adjust for weight loss, CRP/inflammation or HbA1c - so the association cannot yet be attributed to a direct iron-handling effect.
PopulationDanish nationwide register (observational cohort), people with hereditary haemochromatosis + type-2 diabetes.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitspossible confounding by indication
Comparatorsno treatment
GLP-1 RA class MARKETED
Safety signals Decrease
Low evidence

A narrative review reports that GLP-1 RA users have 26-30% lower ferritin than SGLT2i comparators with frequent iron depletion, attributing it to appetite suppression,...

Urbina et al., GLP-1 receptor agonists and iron status, Clin Obes 2026;16:e70070 Source
Full findingA narrative review reports that GLP-1 RA users have 26-30% lower ferritin than SGLT2i comparators with frequent iron depletion, attributing it to appetite suppression, delayed gastric emptying and altered absorption.
PopulationNarrative review (Urbina et al., Clin Obes 2026) summarising GLP-1 RA iron-status literature.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsSecondary / narrative source; rests largely on the single Bain register. Confidence medium. Review, not primary data.
ComparatorsSGLT-2 inhibitor
GLP-1 RA class MARKETED
Safety signals No change
Low evidence

The lowering effect is NOT universal: a 700-patient retrospective GLP-1 analogue cohort found no significant change in ferritin (haemoglobin fell 0.2 g/dL and 8.4%...

Effect of GLP-1 receptor agonists on haematological and iron indices: a retrospective coh... Source
Full findingThe lowering effect is NOT universal: a 700-patient retrospective GLP-1 analogue cohort found no significant change in ferritin (haemoglobin fell 0.2 g/dL and 8.4% developed anaemia), which is counter-evidence to the class-wide ferritin-lowering claim.
Population700-patient retrospective observational cohort of GLP-1 analogue users (Saudi Med J 2025); ferritin a secondary endpoint.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsFerritin was a secondary endpoint with no p-value or magnitude reported; possible underpowering. Counter-evidence to C-CLASS-IRON-01. Observational cohort.
Comparatorsbaseline
GLP-1 RA class MARKETED
Safety signals Not directional
Low evidence

Interpretive key bounding all direction findings: ferritin is a positive acute-phase reactant, so an elevated value may reflect inflammation not iron stores, and a...

Urbina et al., GLP-1 receptor agonists and iron status, Clin Obes 2026;16:e70070 Source
Full findingInterpretive key bounding all direction findings: ferritin is a positive acute-phase reactant, so an elevated value may reflect inflammation not iron stores, and a fall during weight loss / reduced steatosis on these drugs may partly reflect resolving inflammation rather than only true iron depletion.
PopulationNarrative review (Urbina et al., Clin Obes 2026) plus acute-phase-reactant physiology (AASLD Liver Fellow Network; PMC2893236/PMC5878890/PMC5223018).
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsInterpretive key; bounds the meaning of every direction finding in this cluster. Note AASLD Liver Fellow Network and PMC2893236/PMC5878890/PMC5223018. Review-level.
Comparatorsnot applicable
Dulaglutide MARKETED
Safety signals No change
High evidence

Short-term dulaglutide did not alter sexual desire or the reproductive axis in healthy lean men.

Dulaglutide on male sexual function and HPG axis (RCT), EBioMedicine 2024 Source
PopulationPeer-reviewed primary (women's-health wave)
Fundingacademic-Swiss National Science Foundation and Swiss foundations
Scope limitsA counter-pole AGAINST a direct libido effect (no weight-loss confound in lean men). Narrow: lean, eugonadal, 4 weeks. Pairs with the existing libido verdict.
GLP-1 (native; Physiology) MARKETED
Safety signals No change
Low evidence

Acute GLP-1 infusion did not affect reproductive-hormone secretion in healthy men, contradicting rodent findings.

Acute GLP-1 infusion on the male reproductive axis (crossover RCT), J Clin Endocrinol Met... Source
PopulationAcute single-blind randomised placebo-controlled crossover RCT (8-h GLP-1 infusion, healthy men; small acute mechanistic study).
Fundingacademic-UK public (NIHR / MRC / Wellcome Trust / BBSRC / Imperial)
Scope limitssurrogate/exploratory endpoint
Comparatorsplacebo infusion
Semaglutide MARKETED
Safety signals Increase
Moderate evidence

In a PCOS RCT, semaglutide improved menstrual-cycle recovery - a weight-loss-mediated effect.

Semaglutide+metformin in PCOS (open-label RCT, n=100), Reprod Biol Endocrinol 2025 Source
PopulationPCOS open-label RCT (Reprod Biol Endocrinol 2025): 100 overweight/obese women with PCOS (Rotterdam criteria), prospective randomised controlled open-label trial of semaglutide 1 mg weekly plus metformin vs metformin alone, 16 weeks.
Fundingacademic/government - Chinese government and institutional grants (Chongqing Health Commission/Science & Technology Bureau; NSFC; not industry)
Scope limitsWEIGHT-MEDIATED PCOS menstrual recovery; does NOT isolate a drug-intrinsic abnormal-uterine-bleeding mechanism - the drug-intrinsic AUB signal remains spontaneous-report-only. DEEPENS the menstrual signal row.
GLP-1 RA class MARKETED
Safety signals Decrease
Low evidence

The same narrative review reports vitamin-D deficiency as the most common micronutrient abnormality on GLP-1 RA therapy (7.5% at 6 mo / 13.6% at 12 mo in an n=69...

Urbina et al., GLP-1 receptor agonists and iron status, Clin Obes 2026;16:e70070 Source
Full findingThe same narrative review reports vitamin-D deficiency as the most common micronutrient abnormality on GLP-1 RA therapy (7.5% at 6 mo / 13.6% at 12 mo in an n=69 sub-study) and intakes below the DRI for calcium and iron in >60% of patients - but these are intake/small-substudy data, not serum status.
PopulationNarrative review (Urbina et al., Clin Obes 2026) summarising GLP-1 RA micronutrient-status literature; the vitamin-D-deficiency rates from an n=69 sub-study.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsCONFIDENCE medium; low-grade (narrative review of INTAKE not serum). Same source + domain as the iron finding C-CLASS-IRON-04 (bumps Urbina n_findings to 4). B12, folate and magnesium are NOT verified by this source - explicit gaps (routed to OQ-BMD-C). Do not read the 7.5%/13.6% deficiency rates as a cohort-wide serum prevalence.
ComparatorsSGLT-2 inhibitor
GLP-1 RA class MARKETED
Safety signals Mixed
Low evidence

In a large nationwide cohort, periconceptional GLP-1 exposure raised preterm-birth risk only among diabetes-indication users, not weight-management users - implicating...

Periconceptional GLP-1 exposure and pregnancy outcomes (Danish nationwide cohort), Hum Re... Source
Full findingIn a large nationwide cohort, periconceptional GLP-1 exposure raised preterm-birth risk only among diabetes-indication users, not weight-management users - implicating the underlying disease rather than the drug.
PopulationPeer-reviewed primary (women's-health wave)
Fundingacademic / investigator (not separately extracted)
Scope limitsFills the non-diabetic-obese pregnancy gap the prior T2D-only cohort missed. Observational, 529 exposed, residual confounding by glycaemic control; preterm birth not malformation. DEEPENS the class pregnancy rows.
GLP-1 RA class MARKETED
Safety signals Increase
Very low evidence

NET VERDICT (acute kidney injury) - a LOW/very-low-grade pharmacovigilance signal that is mostly VOLUME-DEPLETION-mediated, i.e. secondary to dehydration from GI...

Consolidation of GLP-1RA AKI pharmacovigilance (volume-depletion mechanism) + comparative...
Full findingNET VERDICT (acute kidney injury) - a LOW/very-low-grade pharmacovigilance signal that is mostly VOLUME-DEPLETION-mediated, i.e. secondary to dehydration from GI adverse events (vomiting/diarrhoea/poor intake), NOT a primary nephrotoxic effect. Tirzepatide reported less than semaglutide (reporting, not incidence). Higher risk in pre-existing renal impairment. This is the AE signal; longer-term renal OUTCOMES are favourable and live in the renal domain.
PopulationFAERS pharmacovigilance + case literature; comparative tirz-vs-sema FAERS.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsidentifier not fully verified
Comparatorssemaglutide (for tirzepatide comparison); background FAERS reporting
GLP-1 RA class MARKETED
Safety signals Increase
Very low evidence

GLP-1RA-associated acute kidney injury reported in pharmacovigilance/case literature, proposed mechanism dehydration from vomiting/diarrhoea/poor intake; renal...

Dong & Sun, Front Endocrinol 2022 (GLP-1RA AKI FAERS disproportionality) Source
Full findingGLP-1RA-associated acute kidney injury reported in pharmacovigilance/case literature, proposed mechanism dehydration from vomiting/diarrhoea/poor intake; renal disorders the second-largest AE category after GI in one case series.
PopulationPost-marketing pharmacovigilance + case reports/review
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsdisproportionality: reporting != incidence/causality
GLP-1 RA class MARKETED
Safety signals Mixed
Moderate evidence

Peri-operative aspiration meta-analysis: GLP-1 RA use associated with sharply increased residual gastric contents despite appropriate fasting, but NOT with increased...

Elkin J et al., Anaesthesia 2025 Source
Full findingPeri-operative aspiration meta-analysis: GLP-1 RA use associated with sharply increased residual gastric contents despite appropriate fasting, but NOT with increased pulmonary aspiration; withholding at least one dose lowered residual-contents odds.
PopulationMeta-analysis, 28 observational studies, fasted patients undergoing anaesthesia/sedation
Fundingacademic/independent - investigator (Australian Government Research Training Program Scholarship); no industry study sponsor
Scope limitsCentral anaesthesia tension: retained contents up ~6-fold yet no measurable rise in actual aspiration (low/very-low GRADE). Underlies ASA/multi-society pre-procedure hold guidance.
Comparatorsnon-GLP-1 RA exposure
GLP-1 RA class MARKETED
Safety signals Increase
Moderate evidence

Peri-procedural meta-analysis: pre-procedural GLP-1 RA increased pre-procedural GI symptoms and elevated residual gastric content vs control, with no significant...

do Nascimento TS et al., Perioper Med (Lond) 2024 Source
Full findingPeri-procedural meta-analysis: pre-procedural GLP-1 RA increased pre-procedural GI symptoms and elevated residual gastric content vs control, with no significant difference in PONV or 30-day mortality.
PopulationMeta-analysis, 14 RCTs/observational, 2143 adults, elective surgery/procedures
Fundingacademic/independent - self-funded (no external sponsorship)
Scope limitsConcordant with Elkin on residual gastric content; also reports peri-procedural glycaemic benefit.
Comparatorscontrol (no GLP-1 RA)
Tirzepatide MARKETED
Safety signals Increase
Low evidence

Anaesthesia narrative reviews: GLP-1 RAs and tirzepatide delay gastric emptying and raise aspiration considerations; data preliminary/conflicting; gastric ultrasound...

Doroba O et al., Anaesthesiol Intensive Ther 2025; Kwak HJ et al., Korean J Anesthesiol 2026 Source
Full findingAnaesthesia narrative reviews: GLP-1 RAs and tirzepatide delay gastric emptying and raise aspiration considerations; data preliminary/conflicting; gastric ultrasound recommended; guidance is multi-society expert consensus.
PopulationNarrative reviews of peri-operative management of novel antidiabetic/anti-obesity drugs
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsKwak 2026 also flags a 'misidentification trap' (AOM adverse effects mistaken for surgical/anaesthetic complications), citing semaglutide NAION HR 7.64 and a WHO 2025 alert. Two DOIs bundled.
ComparatorsSGLT2 inhibitors (contrast)
GLP-1 RA class MARKETED
Safety signals Decrease
High evidence

FOLK-CLAIM VERDICT ('reduced inflammation / joint pain relief / skin improvements'): MIXED, and the mechanism-split is the whole story. (1) Knee-OA pain relief = TRUE...

Bliddal H et al. Semaglutide in knee osteoarthritis with obesity (STEP-9). N Engl J Med 2... Source
Full findingFOLK-CLAIM VERDICT ('reduced inflammation / joint pain relief / skin improvements'): MIXED, and the mechanism-split is the whole story. (1) Knee-OA pain relief = TRUE but predominantly WEIGHT-LOSS-mediated (less joint load; STEP-9 real and large, but tracks weight and the placebo arm also improved - not proven direct chondroprotection). (2) Systemic inflammation / CRP reduction = TRUE and PARTLY DIRECT (CRP falls somewhat beyond weight loss in SELECT), though magnitude still mostly adiposity-coupled. (3) Skin (psoriasis, hidradenitis) = UNPROVEN (small/uncontrolled, weight-confounded).
PopulationSemaglutide knee-OA RCT (STEP-9) + reta knee-OA phase-3 topline (TRIUMPH-4) + CRP data (SELECT/HFpEF) + small skin series.
Fundingindustry - Novo Nordisk (trial sponsor; disclosed)
Scope limitsknee-OA / obesity population; composite finding also carries press-topline (TRIUMPH-4) and small-series strands separately graded
Comparatorsplacebo
GLP-1 RA class MARKETED
Safety signals Increase
Moderate evidence

NET VERDICT (peri-operative aspiration) - the most clinically live procedural signal: by delaying gastric emptying these agents leave residual gastric contents despite...

Elkin J et al., Anaesthesia 2025 Source
Full findingNET VERDICT (peri-operative aspiration) - the most clinically live procedural signal: by delaying gastric emptying these agents leave residual gastric contents despite guideline fasting, raising a theoretical aspiration risk under anaesthesia/sedation. Meta-analysis robustly demonstrates the RETAINED-CONTENTS surrogate but does NOT demonstrate increased actual pulmonary aspiration. Operationally live because multi-society/ASA guidance now recommends mitigation.
PopulationPatients on GLP-1RAs undergoing anaesthesia/endoscopy/sedation; meta-analyses of peri-procedural cohorts + gastric-ultrasound studies; semaglutide/liraglutide-era data; no reta-direct.
Fundingacademic/independent - investigator (Australian Government Research Training Program Scholarship); no industry study sponsor
Scope limitsGRADE SPLIT: retained-gastric-contents surrogate = moderate (consistent, ~6-fold); actual pulmonary-aspiration hard outcome = low/very-low and NOT demonstrated to increase; guidance pole = expert multi-society consensus (moderate, not an agency label). Both poles: ANCHOR = Elkin (ANAES17) + do Nascimento (ANAES18) + Wu (ASP09); GUIDANCE = the new Kindel row; CAVEAT = narrative reviews call data preliminary, recommend gastric ultrasound (ANAES19), flag the drug-AE-vs-surgical-complication misidentification trap. RETA POSITION: reta is GI-dominant and shares the delayed-gastric-emptying mechanism, so the retained-contents class-transfer expectation applies; no reta-direct peri-operative data. VALIDATOR: confirm PMID 40230298 (retained contents ~6-fold, no aspiration increase).
Comparatorsnon-GLP-1-RA controls; fasted controls; dose-withheld vs continued
GLP-1 RA class MARKETED
Safety signals Not directional
Moderate evidence

Multi-society clinical practice guidance for safe peri-operative use of GLP-1 RAs: individualised risk-stratified management rather than fixed cessation, balancing...

Kindel TL, Wang AY, Wadhwa A et al. (multisociety), Clin Gastroenterol Hepatol, 2024 Source
Full findingMulti-society clinical practice guidance for safe peri-operative use of GLP-1 RAs: individualised risk-stratified management rather than fixed cessation, balancing aspiration-risk mitigation against the harms of interrupting therapy. Operationalises the earlier ASA October-2023 consensus (which advised holding GLP-1 RAs pre-procedure).
PopulationAdults on GLP-1 RAs presenting for elective procedures/anaesthesia/endoscopy.
Fundingprofessional-society guidance - no external/commercial funding (AGA and co-sponsoring societies; author consulting COIs disclosed)
Scope limitsno outcome data yet (ongoing)
Semaglutide MARKETED
Safety signals Increase
Low evidence

In fasting patients undergoing endoscopy under anaesthesia, GLP-1RA therapy associated with markedly higher residual gastric contents, posing additional...

Wu F et al., Can J Anaesth 2024 Source
Full findingIn fasting patients undergoing endoscopy under anaesthesia, GLP-1RA therapy associated with markedly higher residual gastric contents, posing additional pulmonary-aspiration risk.
PopulationRetrospective cohort, single US institution (MGH) 2019-2023, EGD under anaesthesia, 90 vs 102
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsfew events/wide CI
Comparatorspatients starting GLP-1RA after procedure (control)
GLP-1 RA class MARKETED
Safety signals Increase
Moderate evidence

NET VERDICT (gallbladder / biliary) - one of the FEW high-confidence real GI safety signals: randomised-trial meta-analysis shows GLP-1-based therapy increases the...

He L et al., JAMA Intern Med 2022 Source
Full findingNET VERDICT (gallbladder / biliary) - one of the FEW high-confidence real GI safety signals: randomised-trial meta-analysis shows GLP-1-based therapy increases the composite of gallbladder/biliary disease, concentrated at higher doses, longer durations and in weight-loss trials. Leading mechanism is rapid weight loss + reduced gallbladder motility, so it is expected to track with weight-loss magnitude.
PopulationPooled randomised participants across GLP-1RA trials (T2D and obesity) + CV-outcomes RCT-meta + obesity head-to-head meta. No retatrutide-direct biliary endpoint.
Fundingacademic-Chinese public (NSFC / Beijing NSF / CAMS)
Scope limitsGRADE: high-confidence real (RCT-meta, multiple concordant). STRONG pole = He composite RR ~1.37 (+37%) with dose/weight-loss gradient (BIL01) + Galli (BIL04) + Zeng (BIL02); NUANCE/BRAKE = tirzepatide showed NO significant biliary excess in obesity-only (BIL03) - a genuine brake on the reta-amplification expectation, since reta is mechanistically closer to the dual/triple agents than to semaglutide; a semaglutide bile-duct-cancer VigiBase signal is very-low/contested (BIL15). RETA POSITION: reta is the most weight-loss-potent agent and the signal scales with weight loss, so shared (plausibly greater) biliary risk is a reasonable class-transfer expectation - expectation, NOT observation (no reta-direct endpoint). VALIDATED: PMID 35344001 (He JAMA Intern Med 2022) confirms composite RR 1.37 (95% CI 1.23-1.52); the ~1.27/+26% figure is the cholelithiasis sub-component, corrected.
Comparatorsplacebo; active comparators; semaglutide; tirzepatide
Semaglutide MARKETED
Safety signals Increase
Moderate evidence

GLP-1 RA randomisation associated with increased composite of gallbladder/biliary disease (cholelithiasis, cholecystitis, biliary disease); higher at higher doses,...

He L et al., JAMA Intern Med 2022 Source
Full findingGLP-1 RA randomisation associated with increased composite of gallbladder/biliary disease (cholelithiasis, cholecystitis, biliary disease); higher at higher doses, longer durations, and in weight-loss trials.
Population76 RCTs, 103,371 patients; meta-analysis
Fundingacademic-Chinese public (NSFC / Beijing NSF / CAMS)
Scope limitsCartographic anchor for class biliary signal; dose/duration/weight-loss interaction reported.
Comparatorsplacebo; non-GLP-1 RA drugs
Tirzepatide MARKETED
Safety signals Mixed
Moderate evidence

In a CV-outcomes meta-analysis, GLP-1 RAs increased gallbladder disorders by 26% but showed no difference in pancreatitis or neoplasm.

Galli M et al., J Am Coll Cardiol 2025 Source
Population21 RCTs, 99,599 patients, mean follow-up 2.4 yr; meta-analysis
Fundingacademic / independent - no industry sponsor (investigator grant: Sapienza University of Rome)
Scope limitsNull pole for pancreatitis/neoplasm; gallbladder concordant with class signal.
Comparatorsplacebo; controls
GLP-1 RA class MARKETED
Safety signals No change
Low evidence

NET VERDICT (bone / fracture) - NEUTRAL-to-mildly-negative and LOW-grade: GLP-1R agonists show neutral-to-mildly-negative (non-significant) BMD/turnover effects, but...

Consolidation of GLP-1RA/incretin bone-health appraisal with the rapid-weight-loss/sarcop...
Full findingNET VERDICT (bone / fracture) - NEUTRAL-to-mildly-negative and LOW-grade: GLP-1R agonists show neutral-to-mildly-negative (non-significant) BMD/turnover effects, but fracture risk does NOT appear increased at clinically relevant doses; dual/triple incretin/amylin analogues may even be bone-positive (mostly preclinical). The live concern is RAPID weight loss driving sarcopenia and downstream fracture risk, not a direct osteotoxic drug effect.
PopulationBone-health appraisal/review across GLP-1RA + incretin analogues; preclinical for dual/triple bone-positive signals.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitssurrogate/exploratory endpoint
Comparatorsplacebo; post-bariatric-surgery populations; lifestyle weight loss
GLP-1 RA class MARKETED
Safety signals No change
Low evidence

Bone-health appraisal: GLP-1R agonists show neutral-to-mildly-negative (non-significant) effects on bone turnover/BMD, but fracture risk does NOT appear increased at...

Anastasilakis AD et al., Diabetes Obes Metab 2025 Source
Full findingBone-health appraisal: GLP-1R agonists show neutral-to-mildly-negative (non-significant) effects on bone turnover/BMD, but fracture risk does NOT appear increased at clinically relevant doses; dual/triple incretin and amylin analogues may be bone-positive (mostly preclinical).
PopulationCritical-appraisal review of anti-obesity medications and bone metabolism (clinical + preclinical)
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsDistinguishes pharmacological weight loss from post-bariatric bone loss/fracture increase. Concurring earlier review: Herrou/Paccou PMID:37999750.
GLP-1 RA class MARKETED
Safety signals Decrease
Low evidence

Vs insulin, GLP-1RA initiation associated with LOWER liver and pancreatic cancer risk and no increased risk for most other major cancers, in a large T2D cohort.

Rashid Z et al., J Gen Intern Med 2026 Source
PopulationRetrospective cohort, IBM-MarketScan, T2D 2013-2021, N=106,088, weighted vs insulin
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitspossible confounding by indication
Comparatorsinsulin
GLP-1 RA class MARKETED
Safety signals Mixed
Low evidence

In obesity, GLP-1RA use associated with LOWER overall cancer risk and reduced endometrial/ovarian/meningioma cancer, but a marginally non-significant INCREASED kidney...

Dai H et al., JAMA Oncol 2025 Source
Full findingIn obesity, GLP-1RA use associated with LOWER overall cancer risk and reduced endometrial/ovarian/meningioma cancer, but a marginally non-significant INCREASED kidney cancer risk.
PopulationTarget-trial emulation, OneFlorida+ EHR 2014-2024, 86,632 matched adults with obesity
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsPer PubMed. Kidney-cancer signal echoes Wang 2024 (HR 1.54 vs metformin); recorded as emerging/contested, not a verdict.
Comparatorsnon-users eligible for anti-obesity medication
Semaglutide MARKETED
Safety signals Mixed
Low evidence

In T2D, GLP-1RAs associated with lower risk of 10/13 obesity-associated cancers vs insulin; NO reduction for postmenopausal breast or thyroid cancer; vs metformin,...

Wang L, Xu R, Kaelber DC, Berger NA. JAMA Netw Open 2024 Source
Full findingIn T2D, GLP-1RAs associated with lower risk of 10/13 obesity-associated cancers vs insulin; NO reduction for postmenopausal breast or thyroid cancer; vs metformin, INCREASED kidney cancer.
PopulationRetrospective cohort, US nationwide EHR (113M), 1,651,452 T2D, 2005-2018, 15-yr follow-up, matched
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsPer PubMed. Breast/thyroid 'no reduction' and metformin-comparator kidney-cancer increase are the contested poles. Note pancreatic/gallbladder CANCER (distinct from pancreatitis/cholecystitis) lower vs insulin.
Comparatorsinsulin; metformin
GLP-1 RA class MARKETED
Safety signals Mixed
Low evidence

Mechanistic 'double-edged sword' review: incretin therapies linked in some studies to increased pancreatic/thyroid/cholangiocarcinoma/colorectal cancer (esp....

Mavaddat H et al., Mol Biol Rep 2025 Source
Full findingMechanistic 'double-edged sword' review: incretin therapies linked in some studies to increased pancreatic/thyroid/cholangiocarcinoma/colorectal cancer (esp. genetically predisposed), while showing anticancer effects in prostate, breast, ovarian and others.
PopulationNarrative review of clinical cohorts + in vivo/in vitro
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsPer PubMed. Opposing-direction hypotheses (beta-cell proliferation concern vs antitumour mechanisms); both poles.
GLP-1 RA class MARKETED
Safety signals Mixed
Very low evidence

NET VERDICT (broader cancer) - observational cohorts (confounded by indication) lean reassuring, with a protective pattern for obesity-associated malignancies vs...

Consolidation of GLP-1RA cancer-association cohorts (vs insulin/metformin) with FAERS tum...
Full findingNET VERDICT (broader cancer) - observational cohorts (confounded by indication) lean reassuring, with a protective pattern for obesity-associated malignancies vs insulin (lower liver/pancreatic and 10/13 obesity-associated cancers; lower overall incl. endometrial/ovarian/meningioma in obesity). This is NOT a protective claim and NOT a net-harm verdict: it sits against a contested marginal kidney-cancer signal, no reduction for postmenopausal breast/thyroid, residual pancreatic pharmacovigilance noise, and a mechanistic double-edged-sword hypothesis.
PopulationLarge T2D and obesity observational cohorts + FAERS + mechanistic review.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitspossible confounding by indication
Comparatorsinsulin; metformin; DPP-4 inhibitors; non-users
Semaglutide MARKETED
Safety signals Increase
Low evidence

Multi-database active-comparator emulation (GLP-1RA vs SGLT2i): GLP-1RA associated with ~85% higher presumed-NAION risk, absolute risk small.

Tesfaye H, Patorno E et al., Diabetes Obes Metab 2025 Source
Population482,912 propensity-matched pairs GLP-1RA vs SGLT2i, three US claims databases 2016-2024
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsTarget-trial emulation; signal-confirming but small absolute risk.
ComparatorsSGLT2 inhibitors
GLP-1 RA class MARKETED
Safety signals No change
Moderate evidence

REFUTING/NULL pole at class level: meta-analysis of 28 observational studies found GLP-1 RAs did NOT increase NAION, glaucoma, or retinopathy vs other antidiabetics.

Anatriello A et al., Front Pharmacol 2026 Source
PopulationMeta-analysis, 28 observational studies (6 semaglutide, 22 all GLP-1 RA) in T2D, 2006-2025
Fundingacademic/independent - no financial support received
Scope limitsHigh heterogeneity (I2 ~89%); pooled estimate null. Counterpole to signal records.
Comparatorsother antidiabetic treatments
Tirzepatide|semaglutide (head-to-head) MARKETED
Safety signals Increase
Very low evidence

FAERS disproportionality: strong post-marketing reporting signal for optic ischaemic neuropathy with semaglutide; weaker but significant for tirzepatide and...

Kakkar AK, Payra S, Charaya A, Diabetes Obes Metab 2026 Source
Full findingFAERS disproportionality: strong post-marketing reporting signal for optic ischaemic neuropathy with semaglutide; weaker but significant for tirzepatide and liraglutide; none for dulaglutide/exenatide/lixisenatide.
PopulationFAERS via OpenVigil 2.1, approval-Q3 2025; MedDRA 'optic ischaemic neuropathy', primary suspect
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsdisproportionality: reporting != incidence/causality
Comparatorstirzepatide; liraglutide; dulaglutide; exenatide; lixisenatide
GLP-1 RA class MARKETED
Safety signals Increase
Very low evidence

FOLK-CLAIM VERDICT ('hair loss/shedding around month 3-4'): TRUE that it happens / OVERSTATED as a drug toxicity. Alopecia is a real, RCT-replicated signal (RR ~3.25),...

Cheng & Chang. GLP-1 receptor agonists and hair loss: a meta-analysis. Diabetes Res Clin ... Source
Full findingFOLK-CLAIM VERDICT ('hair loss/shedding around month 3-4'): TRUE that it happens / OVERSTATED as a drug toxicity. Alopecia is a real, RCT-replicated signal (RR ~3.25), and the month 3-4 timing is textbook TELOGEN EFFLUVIUM. But the weight of evidence attributes it predominantly to RAPID WEIGHT LOSS + caloric/nutritional deficit (the classic trigger), NOT a direct drug-on-follicle toxicity - i.e. the drug is largely the vehicle for rapid weight loss. It is REVERSIBLE, dose-/weight-loss-magnitude-dependent and female-biased. Mitigation overlaps the muscle-loss fix (adequate protein + micronutrients: iron, zinc, B12, vitamin D).
PopulationMeta-analysis (7 RCTs) + SURMOUNT-1 trial alopecia rates + FAERS disproportionality + dermatology systematic reviews.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsdisproportionality: reporting != incidence/causality
Comparatorsplacebo
GLP-1 RA class MARKETED
Safety signals Mixed
Very low evidence

NET VERDICT (gastroparesis / ileus / intestinal obstruction) - a WEAK, low-grade signal: the class delays gastric emptying (on-target, prominent in tolerability) and...

GI Safety Assessment of GLP-1 RAs from FAERS, Diagnostics (MDPI) 2024 Source
Full findingNET VERDICT (gastroparesis / ileus / intestinal obstruction) - a WEAK, low-grade signal: the class delays gastric emptying (on-target, prominent in tolerability) and spontaneous reports surface ileus/obstruction events, but randomised-trial-level evidence does NOT confirm elevated mechanical-obstruction risk and dedicated FAERS work found only weak/non-significant signals. Honest net: low-grade, trial-unconfirmed.
PopulationFAERS spontaneous-report databases + a randomised-trials network meta-analysis for the obstruction endpoint. No reta-direct.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsdisproportionality: reporting != incidence/causality
Comparatorsnon-GLP-1-RA reports (FAERS reference); placebo/active (network meta-analysis)
Semaglutide MARKETED
Safety signals No change
Very low evidence

FAERS disproportionality found only WEAK / non-significant intestinal-obstruction signals across GLP-1RAs; no clear class signal for mechanical obstruction.

GI Safety Assessment of GLP-1 RAs from FAERS, Diagnostics (MDPI) 2024 Source
PopulationFAERS 2007-2023, US reports, 16,568 GI AE reports (tirzepatide not included)
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsdisproportionality: reporting != incidence/causality
ComparatorsFAERS background
GLP-1 RA class MARKETED
Safety signals Mixed
Very low evidence

FOLK-CLAIM VERDICT ('libido changes, both up and down'): UNPROVEN / MIXED - no controlled evidence of a direct GLP-1 libido effect in either direction. The only...

Narrative review of GLP-1 RAs and sexual function (men and women): dulaglutide crossover ... Source
Full findingFOLK-CLAIM VERDICT ('libido changes, both up and down'): UNPROVEN / MIXED - no controlled evidence of a direct GLP-1 libido effect in either direction. The only RCT-level human datapoint (dulaglutide crossover) was null; FAERS was non-significant; the plausible 'up' direction is confounded by weight-loss-driven testosterone normalisation and improved body image, and the 'down' direction lacks a significant controlled signal. Bidirectional anecdotes are genuine experiences but do not establish a pharmacological effect.
PopulationOne null dulaglutide RCT (lean men) + FAERS disproportionality + rodent data + online self-report; weight-loss/testosterone confound.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsanimal data; human relevance uncertain; disproportionality: reporting != incidence/causality
Comparatorsplacebo
Semaglutide MARKETED
Safety signals Not directional
Very low evidence

FOLK-CLAIM VERDICT ('menstrual changes - intermenstrual/heavy/irregular bleeding'): MIXED / EMERGING - no longer pure self-report. Two independent low-grade signals...

Lee & Kim. Reproductive/hormonal adverse-event disproportionality of GLP-1 RAs (FAERS): s... Source
Full findingFOLK-CLAIM VERDICT ('menstrual changes - intermenstrual/heavy/irregular bleeding'): MIXED / EMERGING - no longer pure self-report. Two independent low-grade signals now converge (online self-report + a semaglutide-specific FAERS reproductive signal), but it is NOT trial-grade: FAERS cannot establish incidence/causation (reporting bias, no denominator, and weight loss itself shifts cycles). Notably the pharmacovigilance signal is AGENT-SPECIFIC (semaglutide), with tirzepatide/dulaglutide trending the opposite way.
PopulationOnline self-report cohort + FAERS disproportionality; no dedicated RCT endpoint.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsdisproportionality: reporting != incidence/causality
Semaglutide MARKETED
Safety signals No change
High evidence

EMA PRAC concluded its class review and found no evidence of a causal association with suicidal/self-injurious thoughts/actions; no product-information update...

EMA PRAC, Meeting highlights 8-11 April 2024 Source
Full findingEMA PRAC concluded its class review and found no evidence of a causal association with suicidal/self-injurious thoughts/actions; no product-information update warranted. Triggered by Icelandic case reports (initially 3), ~150 reports analysed.
PopulationRegulatory review of non-clinical, clinical-trial, post-marketing and observational data; Jul 2023-Apr 2024
Fundingregulatory agency (FDA/EMA/MHRA/WHO)
Scope limitsNo-signal pole. EMA-commissioned final study report (16 Feb 2024) informed the conclusion.
Tirzepatide|semaglutide (head-to-head) MARKETED
Safety signals No change
High evidence

FDA, after a comprehensive review incl. a meta-analysis of 91 trials, found no increased suicidality risk and REQUESTED REMOVAL of the suicidal-behaviour-and-ideation...

FDA Drug Safety Communication, 'FDA Requests Removal of Suicidal Behavior and Ideation Wa... Source
Full findingFDA, after a comprehensive review incl. a meta-analysis of 91 trials, found no increased suicidality risk and REQUESTED REMOVAL of the suicidal-behaviour-and-ideation warning from labels for liraglutide, semaglutide 2.4 mg and tirzepatide.
PopulationFDA pooled clinical-trial meta-analysis + post-marketing/observational review
Fundingregulatory agency (FDA/EMA/MHRA/WHO)
Scope limitsStrongest regulatory conclusion to date (warning REMOVAL). Began as a 2023 FDA investigation into post-marketing suicidality + aspiration reports; interim Jan-2024 DSC already found no evidence of causation.
Comparatorsplacebo
Tirzepatide|semaglutide (head-to-head) MARKETED
Safety signals Mixed
Very low evidence

VigiBase (WHO) disproportionality: significantly increased ROR for suicidal IDEATION with semaglutide, liraglutide, tirzepatide, and for 'depression/suicidal' and...

McIntyre RS et al., J Affect Disord 2024;369:922-927 Source
Full findingVigiBase (WHO) disproportionality: significantly increased ROR for suicidal IDEATION with semaglutide, liraglutide, tirzepatide, and for 'depression/suicidal' and suicidal behaviour with semaglutide/liraglutide; BUT significantly DECREASED ROR for suicide attempts and completed suicide.
PopulationWHO VigiBase reports, inception-Jan 2024; disproportionality
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsdisproportionality: reporting != incidence/causality
Comparatorsfull database background
Semaglutide MARKETED
Safety signals No change
Very low evidence

FAERS disproportionality (2018-2022): no signal of disproportionate reporting for suicidal/self-injurious behaviours; co-medication analysis flagged...

Zhou J et al., BMC Med 2024;22(1):65 Source
Full findingFAERS disproportionality (2018-2022): no signal of disproportionate reporting for suicidal/self-injurious behaviours; co-medication analysis flagged psychiatric-comorbidity proxies.
PopulationFAERS 2018-2022; disproportionality (information component)
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsdisproportionality: reporting != incidence/causality
Comparatorsfull database background
Tirzepatide|semaglutide (head-to-head) MARKETED
Safety signals Mixed
Very low evidence

FAERS unmasking analysis (2005-2023) with metformin/orlistat comparators: per-agent RORs for psychiatric ADRs elevated for semaglutide (2.03), tirzepatide (1.76),...

Guirguis A et al., Eur Neuropsychopharmacol 2024;82:82-91 Source
Full findingFAERS unmasking analysis (2005-2023) with metformin/orlistat comparators: per-agent RORs for psychiatric ADRs elevated for semaglutide (2.03), tirzepatide (1.76), liraglutide (1.64) but lower than metformin; 42 deaths incl. 13 completed suicides; no causal link inferable.
PopulationFAERS 2005-2023, psychiatric-disorder ADRs, metformin/orlistat comparators; unmasking + disproportionality
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsdisproportionality: reporting != incidence/causality
Comparatorsmetformin; orlistat
Semaglutide MARKETED
Safety signals No change
Very low evidence

FAERS disproportionality (2005-2023): no overall disproportionate increase in suicide/self-injury; a marginal ROR elevation in children was NOT confirmed by EBGM05.

Chen C et al., Eur Psychiatry 2023;66(1):e99 Source
PopulationFAERS 2005 Q2-2023 Q2; 534 cases; ROR + EBGM with age/sex stratification
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsidentifier not fully verified
Comparatorsfull database background
Semaglutide MARKETED
Safety signals No change
Low evidence

Propensity-weighted population-based cohort (Diabetologia): assessed GLP-1 RA association with suicidal ideation/self-injury in diabetes and obesity; part of the...

Population-based cohort, Diabetologia 2024 Source
Full findingPropensity-weighted population-based cohort (Diabetologia): assessed GLP-1 RA association with suicidal ideation/self-injury in diabetes and obesity; part of the cohort evidence body informing regulators.
PopulationIndividuals with diabetes and obesity; propensity-weighted population-based cohort
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsAdditional cohort-pole data point. Exact HRs not extracted this pass (PMC11519213 available); recorded with confirmed DOI.
Comparatorsactive comparators
GLP-1 RA class MARKETED
Safety signals Mixed
Low evidence

NET VERDICT (thyroid C-cell / MTC) - a RODENT-based FDA boxed warning and class contraindication (personal/family MTC history, or MEN 2) coexists with a...

Consolidation of the FDA semaglutide/tirzepatide boxed warning with human cohort + pharma...
Full findingNET VERDICT (thyroid C-cell / MTC) - a RODENT-based FDA boxed warning and class contraindication (personal/family MTC history, or MEN 2) coexists with a NULL-to-unconfirmed HUMAN signal. The regulatory contraindication stands as a labelling FACT while no human MTC excess is confirmed - the rodent C-cell tumourigenic effect does NOT translate (human calcitonin screening negative; null cohorts dominate over reporting-driven signal poles).
PopulationRodent toxicology (mice/rats) underpinning labels; human pharmacovigilance + national active-comparator cohorts (SNDS, Scandinavian, Korean) + FAERS; prospective calcitonin screening (liraglutide programme).
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsanimal data; human relevance uncertain; identifier not fully verified
Comparatorsplacebo; DPP-4 inhibitors; other antidiabetics; no-treatment cohorts
GLP-1 RA class MARKETED
Safety signals Increase
Low evidence

SIGNAL pole: French SNDS nested case-control found GLP-1 RA use for 1-3 years associated with increased all-thyroid-cancer AND medullary thyroid cancer risk.

Bezin J et al., Diabetes Care 2023 Source
Population2562 thyroid-cancer cases vs 45,184 controls; T2D on second-line antidiabetics 2006-2018, France
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitspossible confounding by indication
ComparatorsGLP-1 RA non-users among T2D
GLP-1 RA class MARKETED
Safety signals No change
Low evidence

REFUTING pole: Scandinavian three-country active-comparator cohort found no substantially increased thyroid cancer risk vs DPP-4 inhibitors; MTC estimate...

Pasternak B et al., BMJ 2024 Source
Full findingREFUTING pole: Scandinavian three-country active-comparator cohort found no substantially increased thyroid cancer risk vs DPP-4 inhibitors; MTC estimate imprecise/null on point estimate.
Population145,410 GLP-1 RA vs 291,667 DPP-4i initiators; Denmark/Norway/Sweden 2007-2021; mean follow-up 3.9 yr
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsNULL/refuting pole against Bezin; upper CI consistent with no more than 31% relative increase.
ComparatorsDPP-4 inhibitors; SGLT2 inhibitors
GLP-1 RA class MARKETED
Safety signals No change
Low evidence

Second NULL pole: Korean nationwide cohort found no association with new-onset cancers incl. pancreatic and MTC; thyroid point estimate >1 but NS.

Kim M et al., Diabetes Metab J 2024 Source
Population7827 propensity-matched (GLP-1 RA / DM control / non-DM control); Korean NHIS 2004-2021; median follow-up 8 yr
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsLonger median follow-up (8 yr).
ComparatorsDM controls; non-DM controls
GLP-1 RA class MARKETED
Safety signals Mixed
Very low evidence

FAERS tumour disproportionality (2004-2021): NO overall increase at system-organ-class level, but significant signals for MTC, papillary thyroid cancer, malignant...

Yang Z et al., Front Pharmacol 2022 Source
Full findingFAERS tumour disproportionality (2004-2021): NO overall increase at system-organ-class level, but significant signals for MTC, papillary thyroid cancer, malignant pancreatic neoplasms and islet-cell neoplasms.
Population8718 GLP-1 RA tumour reports; FAERS Q1 2004-Q2 2021; disproportionality
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsdisproportionality: reporting != incidence/causality
ComparatorsFAERS background
GLP-1 RA class MARKETED
Safety signals Decrease
Moderate evidence

Network meta-analysis (body composition): potent agents produce greatest fat-mass loss but significant ABSOLUTE lean-mass loss; RELATIVE (% baseline) lean mass...

Karakasis P et al., Metabolism 2024 Source
Full findingNetwork meta-analysis (body composition): potent agents produce greatest fat-mass loss but significant ABSOLUTE lean-mass loss; RELATIVE (% baseline) lean mass unchanged. Tirzepatide/semaglutide most effective for weight/fat, among least effective at preserving lean mass.
PopulationNetwork meta-analysis, 22 RCTs, 2258 participants (diabetes and/or overweight/obesity), through Nov 2024
Fundingacademic / independent - no specific grant funding
Scope limitsAbsolute vs relative lean-mass framings both recorded. Liraglutide was the only GLP-1 RA achieving significant weight loss without significant lean-mass reduction. Cross-links body-composition.
Comparatorsplacebo; liraglutide; tirzepatide; semaglutide
Tirzepatide|semaglutide (head-to-head) MARKETED
Safety signals Decrease
Low evidence

Narrative review framing: incretin agents cause rapid significant lean-mass loss (~10% of body weight, ~6 kg), characterised as comparable to a decade+ of ageing,...

Locatelli JC et al., Diabetes Care 2024 Source
Full findingNarrative review framing: incretin agents cause rapid significant lean-mass loss (~10% of body weight, ~6 kg), characterised as comparable to a decade+ of ageing, raising sarcopenia/frailty concern; resistance exercise proposed to preserve muscle.
PopulationNarrative review across liraglutide, semaglutide, tirzepatide, retatrutide (~15-24% weight loss)
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limits'Ageing-equivalent' framing is the authors' characterisation, not a measured endpoint. Includes retatrutide. Counterpoint in C-CLASS-SAFETY-MUSCLE15.
Tirzepatide|semaglutide (head-to-head) MARKETED
Safety signals Mixed
Very low evidence

Opposite-pole mechanistic view: emerging preclinical/translational data suggest possible muscle-specific BENEFICIAL effects (attenuated atrophy, improved...

Koceva A, Janez A, Jensterle M, Medicina (Kaunas) 2025 Source
Full findingOpposite-pole mechanistic view: emerging preclinical/translational data suggest possible muscle-specific BENEFICIAL effects (attenuated atrophy, improved myogenesis/mitochondrial function, reduced myosteatosis), alongside clinical proportional fat/lean loss.
PopulationNarrative review of preclinical (animal) and clinical evidence on skeletal muscle
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsanimal data; human relevance uncertain
Semaglutide MARKETED
Safety signals Increase
Moderate evidence

NET VERDICT (NAION, non-arteritic anterior ischaemic optic neuropathy) - a REAL but DEBATED and rare class signal: observational cohorts split (some ~doubled risk,...

Natividade GR et al., JAMA Ophthalmol, 2025 (RCT-level ocular meta) consolidating observa... Source
Full findingNET VERDICT (NAION, non-arteritic anterior ischaemic optic neuropathy) - a REAL but DEBATED and rare class signal: observational cohorts split (some ~doubled risk, others null/protective); the 2025 RCT-level meta-analysis found a significant NAION Peto OR 3.92 but TSA judged the data insufficient for a definitive conclusion; EMA/PRAC added NAION to the semaglutide label (frequency 'unknown'/very rare). Absolute incidence is small throughout.
PopulationAdults with T2D and overweight/obesity; signal strongest in T2D, longer follow-up (>=2 yr) and with hypertension. RCT meta n=73,640; observational cohorts range single-centre to nationwide.
Fundingacademic / investigator-initiated; no industry sponsor found in indexed metadata (Europe PMC fundingList empty); full JAMA COI disclosures paywalled
Scope limitssingle-centre/referral-enriched
Comparatorsplacebo; non-GLP-1RA antidiabetics; SGLT2i; active comparators
GLP-1 RA class MARKETED
Safety signals No change
Moderate evidence

NET VERDICT (pancreatitis / pancreatic cancer) - largely REASSURED at trial level: randomised and meta-analytic evidence shows no clear increase in pancreatitis (any...

Wen J et al., Endocrinol Diabetes Metab 2025 Source
Full findingNET VERDICT (pancreatitis / pancreatic cancer) - largely REASSURED at trial level: randomised and meta-analytic evidence shows no clear increase in pancreatitis (any nominal excess attenuates on stratification) and no overall pancreatic-cancer association. Against this sits a persistent FAERS reporting signal (reporting != incidence). Net: not a confirmed real signal at trial level, with the FAERS pole retained as a low-grade caveat.
PopulationPooled randomised trial participants (the Wen 2025 meta reportedly INCLUDES retatrutide); CV-outcomes trial populations; FAERS.
Fundingnone-declared (independent meta-analysis)
Scope limitsGRADE: REASSURING at RCT-meta (moderate evidence of no clear increase) vs very-low FAERS reporting signal. NULL pole = Wen (PANC05) + Galli (BIL04); SIGNAL pole = FAERS liraglutide pancreatitis (PV07), semaglutide pancreatic-cancer (PV06), + the residual with-background-medication pancreatic-cancer stratum in Wen - all reporting != incidence. RETA POSITION: reta is reportedly INCLUDED in Wen's pooled trials, so it shares the reassuring trial-level pole DIRECTLY (not merely class-transfer); no reta-specific pancreatitis excess. VALIDATOR: confirm PMID 40988099 (Wen 2025) + whether it includes retatrutide.
Comparatorsplacebo; active comparators; background-medication strata
Retatrutide INVESTIGATIONAL
Safety signals Mixed
Moderate evidence

Significantly increased pancreatitis risk overall, but NOT significant when stratified by background medication; pancreatic cancer not associated overall, but a signal...

Wen J et al., Endocrinol Diabetes Metab 2025 Source
Full findingSignificantly increased pancreatitis risk overall, but NOT significant when stratified by background medication; pancreatic cancer not associated overall, but a signal in the with-background-medication stratum.
Population62 RCTs, 66,232 patients, mean follow-up 43.5 wk; meta-analysis
Fundingnone-declared (independent meta-analysis)
Scope limitsIncludes retatrutide among pooled trials. Contested pancreatitis signal attenuates on stratification - both poles within one study.
Comparatorsplacebo; active comparators
Semaglutide MARKETED
Safety signals No change
Low evidence

Periconceptional GLP-1 RA exposure NOT associated with a large increased major-congenital-malformation risk vs insulin, in a multinational cohort of pregnant women...

Cesta CE et al., JAMA Intern Med 2024 Source
Full findingPericonceptional GLP-1 RA exposure NOT associated with a large increased major-congenital-malformation risk vs insulin, in a multinational cohort of pregnant women with T2D.
PopulationCohort, 4 Nordic + US MarketScan + Israeli Maccabi, 2009-2021; T2D pregnancies, infants to 1 yr
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsPer PubMed. Estimates imprecise/confounded by maternal T2D; no glycaemic-control data. Reassuring but not exonerating.
Comparatorsinsulin; sulfonylureas; DPP-4i; SGLT2i
Tirzepatide|semaglutide (head-to-head) MARKETED
Safety signals Mixed
Low evidence

Animal reproductive-tox studies show adverse offspring outcomes (decreased fetal growth, skeletal/visceral anomalies, embryonic death); no consistent pattern of human...

Drummond RF, Seif KE, Reece EA. Am J Obstet Gynecol 2024 Source
Full findingAnimal reproductive-tox studies show adverse offspring outcomes (decreased fetal growth, skeletal/visceral anomalies, embryonic death); no consistent pattern of human congenital anomalies to date.
PopulationReview of animal repro-tox + human case reports/cohort/population studies
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsanimal data; human relevance uncertain
Comparatorsinsulin
Semaglutide MARKETED
Safety signals Increase
Low evidence

GLP-1 RAs may improve ovulatory function/menstrual regularity (esp. obesity/PCOS), potentially increasing conception and unintended pregnancy; human pregnancy-exposure...

Abedi MM et al., J Clin Med 2026 Source
Full findingGLP-1 RAs may improve ovulatory function/menstrual regularity (esp. obesity/PCOS), potentially increasing conception and unintended pregnancy; human pregnancy-exposure safety data remain limited.
PopulationNarrative review 2020-2025, reproductive-age women
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsPer PubMed. 'Fertility-restoration -> unintended pregnancy' mechanism underlies contraception advice.
GLP-1 RA class MARKETED
Safety signals Increase
Very low evidence

FAERS: liraglutide carried the greatest pancreatitis reporting signal of the class; semaglutide greatest for nausea/vomiting/diarrhoea/constipation.

Liu L et al., Front Endocrinol 2022 Source
PopulationFAERS Jan 2018-Sep 2022; 21,281 GI reports; disproportionality
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsdisproportionality: reporting != incidence/causality
ComparatorsFAERS background
GLP-1 RA class MARKETED
Safety signals Mixed
Low evidence

NET VERDICT (reproductive) - three threads, distinct grades. (1) ORAL hormonal contraceptive efficacy is REDUCED by tirzepatide (delayed gastric emptying) - a real...

Consolidation of the tirzepatide oral-contraceptive labelled interaction with GLP-1RA fer...
Full findingNET VERDICT (reproductive) - three threads, distinct grades. (1) ORAL hormonal contraceptive efficacy is REDUCED by tirzepatide (delayed gastric emptying) - a real LABELLED interaction (barrier/non-oral advised), labelled for tirzepatide but not injectable semaglutide. (2) FERTILITY: GLP-1RAs improve ovulatory function in obesity/PCOS ('Ozempic babies'), raising conception/unintended-pregnancy risk. (3) PREGNANCY: contraindicated - animal repro-tox shows adverse offspring outcomes, while human cohorts show NO large major-malformation excess vs insulin (reassuring but confounded, not exonerating).
PopulationTirzepatide label (PK interaction); GLP-1RA ovulation/PCOS literature; animal reproductive-toxicology + a multinational human pregnancy-exposure cohort (T2D).
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsanimal data; human relevance uncertain; identifier not fully verified
Comparatorsinsulin (pregnancy cohort); non-oral contraceptive methods; pre-treatment baseline (ovulation)
Semaglutide MARKETED
Safety signals Mixed
High evidence

NET VERDICT (early-worsening diabetic retinopathy): SUSTAIN-6 found retinopathy complications significantly MORE frequent with semaglutide than placebo (HR 1.76),...

Marso SP et al. (SUSTAIN-6), NEJM, 2016 Source
Full findingNET VERDICT (early-worsening diabetic retinopathy): SUSTAIN-6 found retinopathy complications significantly MORE frequent with semaglutide than placebo (HR 1.76), widely attributed to RAPID glucose-lowering ('early worsening') in those with pre-existing retinopathy - a KNOWN phenomenon, not necessarily a direct drug effect. At RCT level the 2025 meta found NO overall DR increase (OR 1.04, TSA-sufficient), and a post-hoc RCT showed CRT change explained by glycaemic change rather than drug-specific toxicity.
PopulationT2D at high CV risk with variable baseline retinopathy (SUSTAIN-6, n=3297, 104 wk); pooled RCT n=73,640; post-hoc mechanistic substudy n=40.
Fundingindustry - Novo Nordisk
Scope limitsconference/abstract-level; magnitude web/secondary-sourced
Comparatorsplacebo; empagliflozin; active comparators
GLP-1 RA class MARKETED
Safety signals Mixed
Very low evidence

CROSS-SIGNAL STRUCTURE (the dossier spine) - the class safety signals ranked by EVIDENCE GRADE, not by alarm. HIGH/REAL (RCT or consistent replication):...

Structural synthesis over the safety-other corpus (the per-signal consolidations); the do...
Full findingCROSS-SIGNAL STRUCTURE (the dossier spine) - the class safety signals ranked by EVIDENCE GRADE, not by alarm. HIGH/REAL (RCT or consistent replication): gallbladder/biliary (weight-loss-coupled); rapid-glucose-lowering early diabetic-retinopathy worsening (SUSTAIN-6 HR 1.76; note steady-state pooled DR is NULL, OR 1.04, TSA-sufficient); peri-operative retained-gastric-contents SURROGATE (the surrogate is robust ~6-fold but actual pulmonary aspiration is unproven). CLEARED/NULL in humans: medullary thyroid carcinoma (rodent-basis boxed warning, no human MTC signal); suicidality (regulatory-cleared). DEBATED: NAION (cohorts split; RCT meta OR 3.92 but TSA-insufficient; label 'very rare'). WEAK/pharmacovigilance-only (reporting != incidence): pancreatitis, ileus, acute kidney injury (mostly volume-depletion-mediated).
PopulationClass-wide across GLP-1 mono, GIP/GLP-1 dual, triple, and amylin co-agonists; strength/population vary by signal.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsanimal data; human relevance uncertain; post-hoc (not prespecified); surrogate/exploratory endpoint
Comparatorsplacebo; other antidiabetics; SGLT2i; non-GLP-1RA
GLP-1 RA class MARKETED
Safety signals No change
Moderate evidence

Pooled meta-analyses found NO significant increase in DKA or severe hypoglycaemia with GLP-1 RAs in T1D - but the DKA estimate is VERY LOW certainty and this null does...

Kateel R, Parida A, Chogtu B, Holla SN. Safety of GLP-1 receptor agonists in type 1 diabe... Source
Full findingPooled meta-analyses found NO significant increase in DKA or severe hypoglycaemia with GLP-1 RAs in T1D - but the DKA estimate is VERY LOW certainty and this null does NOT overturn the dose-dependent ketosis signal in the individual ADJUNCT trials.
PopulationGLP-1 RA T1D safety meta-analysis (Kateel et al., 25 studies [23 RCTs + 2 observational]; corroborated by Tan et al. PMC10797415).
Fundingacademic/government (Kasturba Medical College, Manipal; Dept of Health Research, India)
Scope limitsMUST NOT READ AS REASSURANCE: the DKA RR 0.60 is VERY LOW certainty with wide CIs (statistical imprecision); the pool DILUTES the high-dose/liraglutide ketosis signal across lower doses and non-liraglutide agents. It does NOT overturn the dose-dependent hyperglycaemia-with-ketosis seen at liraglutide 1.8mg in the individual trials (C-LIRA-T1D-SAFETY-02). Tan's DKA OR 1.38 is numerically higher but NON-significant. The honest read is UNSETTLED at high dose, not safe. Routed to OQ-T1D-D.
Comparatorsplacebo (insulin background)
GLP-1 RA class MARKETED
Safety signals Mixed
Moderate evidence

A class-level meta-analysis found GLP-1 RAs reduce serum uric acid before-versus-after treatment but NOT significantly versus placebo, and less than active comparators...

Najafi S, Bahrami M, Butler AE, Sahebkar A. The effect of glucagon-like peptide-1 recepto... Source
Full findingA class-level meta-analysis found GLP-1 RAs reduce serum uric acid before-versus-after treatment but NOT significantly versus placebo, and less than active comparators including SGLT2 inhibitors - so the apparent urate-lowering is not an established placebo-controlled drug effect at the class level.
PopulationGLP-1 RA class meta-analysis (Najafi et al., 17 studies; RCTs, observational and uncontrolled studies pooled).
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsSCOPE LIMIT: predates high-dose agents (tirzepatide/retatrutide) and the comparator estimate pools four drug classes. The pre-post drop is confounded by weight loss/regression; the placebo-controlled NS result is the honest class verdict. Two-directional (pre-post down vs placebo NS vs comparator-worse) -> mixed.
Comparatorsplacebo; insulin; metformin; SGLT-2 inhibitor; DPP-4 inhibitor
GLP-1 RA class MARKETED
Safety signals No change
Low evidence

In a large real-world cohort, GLP-1 RAs were gout-neutral on clinical OUTCOMES while SGLT2 inhibitors reduced incident gout and outperformed GLP-1 RAs head-to-head -...

Preston FG et al. SGLT2 inhibitors, but not GLP-1 receptor agonists, reduce incidence of ... Source
Full findingIn a large real-world cohort, GLP-1 RAs were gout-neutral on clinical OUTCOMES while SGLT2 inhibitors reduced incident gout and outperformed GLP-1 RAs head-to-head - the biochemical urate-lowering did not translate into a gout-incidence benefit for GLP-1 RAs.
PopulationTriNetX federated EHR cohort (Preston et al.), T2D on metformin/insulin +/- SGLT2i or GLP-1 RA, propensity-matched, 5-yr gout incidence.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsObservational/EHR, coding-based gout outcomes, confounding by indication. The gout-NEUTRAL summary sub-claim for GLP-1 RAs was 2-1 (not unanimous) - encoded as no-change with that caveat. SGLT2i contrast pole is the genuinely uricosuric comparator.
Comparatorsmetformin; insulin; SGLT-2 inhibitor
GLP-1 RA class MARKETED
Safety signals Increase
Low evidence

A 4-patient case series reported paradoxical transient hyperuricaemia and acute gout flares during rapid GLP-1/GIP-driven weight loss, including a recurrent flare...

Chaaya JA et al. Transient increase in serum uric acid and gout attacks after weight-loss... Source
Full findingA 4-patient case series reported paradoxical transient hyperuricaemia and acute gout flares during rapid GLP-1/GIP-driven weight loss, including a recurrent flare despite urate-lowering therapy and normal uric acid - a hypothesis-generating counter-signal to the net urate-lowering RCT data.
PopulationAACE Endocrinology & Diabetes 2026 observational case series / uncontrolled cohort (Chaaya et al.); 4 adults on tirzepatide or semaglutide with substantial weight loss.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsVery low grade: n=4, uncontrolled, hypothesis-generating; proposed mechanism is ketosis-related renal urate retention during rapid loss. EXCLUDED sub-claim: the '3/4 rose within 3-5 months regardless of baseline urate' statement was REFUTED 0-3 in adversarial review and is deliberately NOT encoded. Contrasts with the net urate-lowering RCT pole.
Comparatorsnone (uncontrolled observational case series)
GLP-1 RA class MARKETED
Safety signals Increase
Low evidence

A real-world cohort found a small but statistically significant HIGHER gout/colchicine signal in GLP-1 users versus non-users - not protective - consistent with a...

Lam DCH et al. Assessing gout risk associated with GLP-1 therapy in obese patients with t... Source
Full findingA real-world cohort found a small but statistically significant HIGHER gout/colchicine signal in GLP-1 users versus non-users - not protective - consistent with a transient-flare or detection-bias effect rather than causal urate-raising.
PopulationTriNetX observational cohort (Lam et al.), overweight/obese T2D, GLP-1 users vs non-users.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsObservational, confounding by indication, absolute difference only 0.2 percentage points; colchicine is an indirect flare proxy (the colchicine sub-claim was 2-1). Consistent with the transient-flare phenomenon / detection bias, NOT demonstrated causal urate-raising. Both-poled against the net urate-lowering RCT data.
Comparatorsnon-users
GLP-1 RA class MARKETED
Safety signals Mixed
Low evidence

In mechanistic renal-physiology trials, acute exenatide transiently raised renal urate excretion without lowering plasma urate, and prolonged liraglutide/lixisenatide...

Tonneijck L et al. Effect of immediate and prolonged GLP-1 receptor agonist administratio... Source
Full findingIn mechanistic renal-physiology trials, acute exenatide transiently raised renal urate excretion without lowering plasma urate, and prolonged liraglutide/lixisenatide produced no urate change - indicating only a marginal, transient tubular effect, not chronic urate-lowering.
PopulationGLP-1 RA renal-physiology trials (Tonneijck et al., post hoc of 4 controlled phase-4 trials; Study-A n=9 healthy, Study-B n=52, Study-C n=36, Study-D n=35 T2D).
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsSmall mechanistic cohorts, normal-urate/low-CV-risk T2D; exploratory (no sample-size calculation). Two-directional: transient uricosuria (excretion up) but plasma urate unchanged/slightly up -> mixed. Authors conclude urate is unlikely to mediate GLP-1 RA cardio-renal benefit. Design = observational cohort -> low (NOT promoted to moderate).
Comparatorsplacebo; insulin glulisine
Dulaglutide MARKETED
Safety signals Mixed
Moderate evidence

In a REWIND exploratory substudy, dulaglutide did NOT significantly reduce incident substantive cognitive impairment on the prespecified primary (unadjusted) analysis;...

Cukierman-Yaffe T, Gerstein HC, Colhoun HM, et al. Effect of dulaglutide on cognitive imp... Source
Full findingIn a REWIND exploratory substudy, dulaglutide did NOT significantly reduce incident substantive cognitive impairment on the prespecified primary (unadjusted) analysis; significance appeared only in a post-hoc baseline-score-adjusted analysis.
PopulationREWIND cognition substudy: N=8828 with baseline plus follow-up MoCA/DSST (of 9901); type 2 diabetes; double-blind placebo-controlled randomised trial; median 5.4 years; NCT01394952.
Fundingindustry - Eli Lilly (trial sponsor; inferred from registration trial)
Scope limitssurrogate/exploratory endpoint
Comparatorsplacebo
Liraglutide MARKETED
Safety signals Decrease
Very low evidence

In an HFE-knockout haemochromatosis mouse model, liraglutide lowered both serum and hepatic iron through a hepcidin-independent mechanism (Hamp not differentially...

Bozadjieva-Kramer N et al. Liraglutide lowers iron in HFE-knockout mice independent of he... Source
Full findingIn an HFE-knockout haemochromatosis mouse model, liraglutide lowered both serum and hepatic iron through a hepcidin-independent mechanism (Hamp not differentially expressed), arguing for a genuine iron-handling effect rather than only an acute-phase change.
PopulationHFE-knockout (HFE-KO) haemochromatosis mice; hepatic and serum iron, Hamp/hepcidin expression measured. Murine model; no human read-across.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsanimal data; human relevance uncertain
Comparatorsvehicle-treated HFE-KO mice
Liraglutide MARKETED
Safety signals No change
High evidence

Rodent C-cell tumour/calcitonin signal does not translate: human sequential calcitonin screening over up to 2 yr in >5000 liraglutide/control subjects showed no...

Hegedus L et al., J Clin Endocrinol Metab 2011 Source
Full findingRodent C-cell tumour/calcitonin signal does not translate: human sequential calcitonin screening over up to 2 yr in >5000 liraglutide/control subjects showed no consistent dose/time-dependent rise and no between-group difference.
Population>5000 subjects with T2D or non-diabetic obesity; calcitonin at 3-month intervals up to 2 yr
Fundingindustry - Novo Nordisk (trial sponsor)
Scope limitsanimal data; human relevance uncertain
Comparatorscontrol therapy
Liraglutide MARKETED
Safety signals Not directional
High evidence

The pivotal-trial investigators themselves concluded that, despite the metabolic benefits, the increased hypoglycaemia and hyperglycaemia-with-ketosis limit the...

Mathieu C, Zinman B, Hemmingsson JU, et al. Efficacy and Safety of Liraglutide Added to I... Source
Full findingThe pivotal-trial investigators themselves concluded that, despite the metabolic benefits, the increased hypoglycaemia and hyperglycaemia-with-ketosis limit the clinical use of liraglutide as an insulin adjunct in T1D - the honest net verdict.
PopulationLiraglutide pivotal double-blind T1D RCTs (Mathieu ADJUNCT ONE; Ahren ADJUNCT TWO) - authors' own conclusions.
Fundingindustry - Novo Nordisk (sponsor; NCT01836523)
Scope limitsThis is the trialists' OWN net judgement (high-grade framing): modest efficacy is outweighed by the disease-specific harm for routine use. Ties the efficacy pole (C-LIRA-T1D-01/02) to the harm pole (C-LIRA-T1D-SAFETY-01/02) and the off-label status (C-CLASS-T1D-OFFLABEL-01).
Comparatorsplacebo (insulin background)
Liraglutide MARKETED
Safety signals Increase
High evidence

Liraglutide added to insulin significantly increased the rate of symptomatic hypoglycaemia in type-1 diabetes - a disease-specific harm that accompanies the modest...

Ahren B, Hirsch IB, Pieber TR, et al. Efficacy and Safety of Liraglutide Added to Capped ... Source
Full findingLiraglutide added to insulin significantly increased the rate of symptomatic hypoglycaemia in type-1 diabetes - a disease-specific harm that accompanies the modest efficacy.
PopulationLiraglutide pivotal double-blind T1D RCTs (Ahren ADJUNCT TWO, 26wk, NCT02098395; corroborated by Mathieu ADJUNCT ONE, NCT01836523).
Fundingindustry - Novo Nordisk (sponsor; NCT02098395)
Scope limitsSYMPTOMATIC (not severe) hypoglycaemia. Note the pooled metas found severe hypoglycaemia NOT increased (Rebelos: similar; Tan: severe-hypo OR 0.86; Kateel: RR 0.74 Low certainty) - the harm is in symptomatic events, the reassurance is only for SEVERE events. Read with C-LIRA-T1D-SAFETY-02.
Comparatorsplacebo (insulin background)
Liraglutide MARKETED
Safety signals Increase
High evidence

Both pivotal trials showed a dose-dependent increase in hyperglycaemia-with-ketosis at the highest liraglutide dose (event rate roughly doubled) - the real,...

Mathieu C, Zinman B, Hemmingsson JU, et al. Efficacy and Safety of Liraglutide Added to I... Source
Full findingBoth pivotal trials showed a dose-dependent increase in hyperglycaemia-with-ketosis at the highest liraglutide dose (event rate roughly doubled) - the real, disease-specific DKA-adjacent safety signal that, with the hypoglycaemia, limits clinical use.
PopulationLiraglutide pivotal double-blind T1D RCTs (Mathieu ADJUNCT ONE, NCT01836523; Ahren ADJUNCT TWO, NCT02098395).
Fundingindustry - Novo Nordisk (sponsor; NCT01836523)
Scope limitsLOAD-BEARING HARM: dose-dependent (1.8mg only), disease-specific, biologically plausible (ketosis on a background of insulin deficiency). This is the individual-trial signal that the pooled-DKA-null (C-CLASS-T1D-SAFETY-03) does NOT overturn - see that finding's cross-ref. With C-LIRA-T1D-SAFETY-01 this is the trialists' stated reason for limiting clinical use.
Comparatorsplacebo (insulin background)
Orforglipron INVESTIGATIONAL
Safety signals Increase
High evidence

AE-related discontinuation rose with orforglipron dose; GI events the commonest AEs, mostly mild-to-moderate, in escalation.

Lilly ATTAIN-1 (NEJM 2025) and ATTAIN-2 results Source
PopulationATTAIN-1 (obesity, no diabetes) and ATTAIN-2 (obesity + T2D) phase 3 trials
Fundingindustry - Eli Lilly
Scope limitsidentifier not fully verified; no outcome data yet (ongoing)
Comparatorsplacebo
Retatrutide INVESTIGATIONAL
Safety signals Decrease
Moderate evidence

In the JCEM metabolite substudy of the two phase-2 retatrutide trials, retatrutide lowered circulating uric acid dose-dependently versus baseline and placebo,...

Pearson SM et al., J Clin Endocrinol Metab 2026 (metabolomics); PubMed null result 2026 (... Source
Full findingIn the JCEM metabolite substudy of the two phase-2 retatrutide trials, retatrutide lowered circulating uric acid dose-dependently versus baseline and placebo, consistent with the weight-mediated class pattern.
PopulationRetatrutide phase-2 obesity + T2D metabolomics substudy (Pearson et al., post hoc of NCT04881760 / NCT05929066).
Fundingindustry - Eli Lilly and Company
Scope limitspost-hoc (not prespecified); small sample (N~282)
Comparatorsplacebo
Retatrutide INVESTIGATIONAL
Safety signals Not directional
Moderate evidence

EXPLICIT ABSENCE: the retatrutide phase-2a MASLD trial (Sanyal 2024) did not report any uric-acid or gout endpoint.

Sanyal AJ et al. Triple hormone receptor agonist retatrutide for metabolic dysfunction-as... Source
PopulationRetatrutide phase-2a MASLD substudy (Sanyal et al., NCT04881760); reviewed for any uric-acid/gout endpoint - none present.
Fundingindustry-Eli Lilly
Scope limitssmall sample (N~98); prespecified/exploratory secondary of RCT (substudy)
Comparatorsplacebo
Retatrutide INVESTIGATIONAL
Safety signals Not directional
Moderate evidence

EXPLICIT ABSENCE: the retatrutide phase-2 obesity trial (Jastreboff 2023) did not report any uric-acid or gout endpoint; the only retatrutide urate data come from the...

Jastreboff AM et al. (retatrutide phase 2), NEJM, 2023;389:514-526 Source
Full findingEXPLICIT ABSENCE: the retatrutide phase-2 obesity trial (Jastreboff 2023) did not report any uric-acid or gout endpoint; the only retatrutide urate data come from the separate JCEM metabolite substudy.
PopulationRetatrutide phase-2 obesity trial (Jastreboff et al., NCT04881760); reviewed for any uric-acid/gout endpoint - none present in the trial report.
Fundingindustry-Eli Lilly
Scope limitsconference/abstract-level; magnitude web/secondary-sourced; surrogate/exploratory endpoint
Comparatorsplacebo
Retatrutide INVESTIGATIONAL
Safety signals Not directional
Moderate evidence

EXPLICIT ABSENCE: the retatrutide phase-2a MASLD trial did not report any iron, ferritin, hepcidin, anaemia or haemoglobin endpoint; its biomarker panel was...

Sanyal AJ et al. Triple hormone receptor agonist retatrutide for metabolic dysfunction-as... Source
Full findingEXPLICIT ABSENCE: the retatrutide phase-2a MASLD trial did not report any iron, ferritin, hepcidin, anaemia or haemoglobin endpoint; its biomarker panel was ALT/AST/FIB-4/K-18/ELF/pro-C3 and no iron variable appears anywhere, including the adverse-event table.
PopulationRetatrutide phase-2a MASLD substudy (Sanyal et al., NCT04881760); reviewed for iron/ferritin/hepcidin/anaemia/haemoglobin reporting - none present.
Fundingindustry-Eli Lilly
Scope limitssmall sample (N~98); prespecified/exploratory secondary of RCT (substudy)
Comparatorsplacebo
Retatrutide INVESTIGATIONAL
Safety signals Not directional
Moderate evidence

EXPLICIT ABSENCE: the retatrutide phase-2 obesity trial did not report any iron, ferritin, hepcidin or anaemia endpoint; its adverse events were gastrointestinal plus...

Jastreboff AM et al. (retatrutide phase 2), NEJM, 2023;389:514-526 Source
Full findingEXPLICIT ABSENCE: the retatrutide phase-2 obesity trial did not report any iron, ferritin, hepcidin or anaemia endpoint; its adverse events were gastrointestinal plus a dose-dependent heart-rate increase only, with no iron variable reported.
PopulationRetatrutide phase-2 obesity trial (Jastreboff et al., NCT04881760); reviewed for iron/ferritin/hepcidin/anaemia reporting - none present.
Fundingindustry-Eli Lilly
Scope limitsconference/abstract-level; magnitude web/secondary-sourced; surrogate/exploratory endpoint
Comparatorsplacebo
Retatrutide INVESTIGATIONAL
Safety signals Not directional
Moderate evidence

EXPLICIT ABSENCE: the retatrutide phase-2 obesity trial did not report any non-iron micronutrient (vitamin D/B12/folate/magnesium/calcium) endpoint - no retatrutide...

Jastreboff AM et al. (retatrutide phase 2), NEJM, 2023;389:514-526 Source
Full findingEXPLICIT ABSENCE: the retatrutide phase-2 obesity trial did not report any non-iron micronutrient (vitamin D/B12/folate/magnesium/calcium) endpoint - no retatrutide micronutrient effect can be asserted or excluded.
PopulationRetatrutide phase-2 obesity trial (Jastreboff et al., NCT04881760); reviewed for any non-iron micronutrient (vitamin D/B12/folate/Mg/Ca) endpoint - none present.
Fundingindustry-Eli Lilly
Scope limitsconference/abstract-level; magnitude web/secondary-sourced; surrogate/exploratory endpoint
Comparatorsplacebo
Retatrutide INVESTIGATIONAL
Safety signals Mixed
Moderate evidence

RETATRUTIDE DIRECT SAFETY position: across the two phase-2 trials the profile is GI-DOMINANT + a DOSE-DEPENDENT HEART-RATE rise, with NO MTC/pancreatitis/NAION/biliary...

Jastreboff AM et al. (retatrutide phase 2), NEJM, 2023;389:514-526 Source
Full findingRETATRUTIDE DIRECT SAFETY position: across the two phase-2 trials the profile is GI-DOMINANT + a DOSE-DEPENDENT HEART-RATE rise, with NO MTC/pancreatitis/NAION/biliary events reported - but these are SHORT (36-48 wk), small per-arm trials, UNDERPOWERED for rare events, so the absence of a signal is NOT clearance. Reta has NO long-term safety data (phase-3 TRIUMPH ongoing).
PopulationPhase-2: obesity (Jastreboff, n=338, 48 wk, 1-12 mg) + T2D (Rosenstock, n=281, 36 wk, 0.5-12 mg, placebo + dulaglutide).
Fundingindustry-Eli Lilly
Scope limitsconference/abstract-level; magnitude web/secondary-sourced; surrogate/exploratory endpoint
Comparatorsplacebo; dulaglutide 1.5 mg
Retatrutide INVESTIGATIONAL
Safety signals Increase
Moderate evidence

FOLK-CLAIM VERDICT ('retatrutide-specific dysesthesia / skin tingling-buzzing, in 5-15% of users, not in the other two'): TRUE / CONFIRMED - and it OVERTURNS the prior...

Jastreboff AM et al. (retatrutide phase 2), NEJM, 2023;389:514-526 Source
Full findingFOLK-CLAIM VERDICT ('retatrutide-specific dysesthesia / skin tingling-buzzing, in 5-15% of users, not in the other two'): TRUE / CONFIRMED - and it OVERTURNS the prior assumption that this was baseless folk chatter. Dysesthesia is a NAMED, DOSE-DEPENDENT, placebo-differentiated, retatrutide-CLASS-SPECIFIC sensory signal (no GLP-1/GIP equivalent), surfaced by the folk-claims loop and NOT previously in the safety dossier (D6/Thread 14). The lay '5-15%' figure if anything UNDERSTATES the 12 mg rate (~21%). Mechanism is UNPROVEN (a glucagon-receptor effect is the leading hypothesis given dose-dependence + class-specificity; rapid weight loss / B-vitamin / electrolyte contributions are partial confounders at best).
PopulationRetatrutide phase-2 obesity trial (skin hyperesthesia ~7%) + phase-3 TRIUMPH-4 topline (dysesthesia 8.8/20.9% at 9/12 mg); no comparable signal for semaglutide or tirzepatide.
Fundingindustry-Eli Lilly
Scope limitsconference/abstract-level; magnitude web/secondary-sourced; surrogate/exploratory endpoint
Comparatorsplacebo
Semaglutide MARKETED
Safety signals Not directional
High evidence

Semaglutide is contraindicated in the US for personal/family history of MTC or MEN 2 (also a boxed warning) and for serious hypersensitivity; the EU contraindication...

Ozempic (semaglutide) US Prescribing Information, Novo Nordisk Source
Full findingSemaglutide is contraindicated in the US for personal/family history of MTC or MEN 2 (also a boxed warning) and for serious hypersensitivity; the EU contraindication is hypersensitivity only (the MTC/MEN2 boxed warning is a US construct).
PopulationRegulatory label / SmPC (primary document)
Fundingregulatory agency (FDA/EMA/MHRA/WHO)
Scope limitsregulatory label; reflects approved labelling, not an independent effect estimate
Semaglutide MARKETED
Safety signals Not directional
High evidence

Anti-semaglutide antibodies develop in roughly 1-3% of patients with no identified clinically significant effect on pharmacokinetics.

Ozempic (semaglutide) US Prescribing Information, Novo Nordisk Source
PopulationRegulatory label / SmPC (primary document)
Fundingregulatory agency (FDA/EMA/MHRA/WHO)
Scope limitsregulatory label; reflects approved labelling, not an independent effect estimate
Semaglutide MARKETED
Safety signals Decrease
Low evidence

In 51 people with type-2 diabetes, 10 weeks of semaglutide attenuated (did not abolish) the post-oral-iron-load serum iron rise, consistent with reduced intestinal...

Melis M et al. Effect of semaglutide on intestinal iron absorption in type-2 diabetes: a ... Source
Full findingIn 51 people with type-2 diabetes, 10 weeks of semaglutide attenuated (did not abolish) the post-oral-iron-load serum iron rise, consistent with reduced intestinal iron absorption on the drug.
Population51 people with type-2 diabetes; single-arm uncontrolled observational pre-post study (no control arm), 10 weeks; post-oral-iron-load serum-iron and TSAT measurement (NCT06629688).
Fundingindustry - Novo Nordisk (trial sponsor; inferred from registration trial)
Scope limitsSmall single-arm pilot, no control, 10 weeks; absorption attenuated not abolished. MANDATORY: do NOT assert the mechanism is proven to be genuine malabsorption rather than an acute-phase effect - that stronger restatement was REFUTED 0-3 in adversarial review; hepcidin and inflammation were not measured.
Comparatorswithin-subject baseline (no control arm)
Semaglutide MARKETED
Safety signals Decrease
Low evidence

The authors attribute the reduced iron absorption (author-hedged 'may') to delayed gastric emptying / altered GI motility, warn it could contribute to iron deficiency...

Melis M et al. Effect of semaglutide on intestinal iron absorption in type-2 diabetes: a ... Source
Full findingThe authors attribute the reduced iron absorption (author-hedged 'may') to delayed gastric emptying / altered GI motility, warn it could contribute to iron deficiency or anaemia in susceptible patients, and suggest monitoring iron status.
Population51 people with type-2 diabetes; single-arm uncontrolled observational pre-post study (no control arm), 10 weeks; post-oral-iron-load serum-iron and TSAT measurement (NCT06629688).
Fundingindustry - Novo Nordisk (trial sponsor; inferred from registration trial)
Scope limitsAuthor interpretation, hedged. Same small single-arm pilot; mechanism attribution is hypothesis, not proven.
Comparatorswithin-subject baseline (no control arm)
Semaglutide MARKETED
Safety signals Mixed
Moderate evidence

In obesity without diabetes, semaglutide increased gallbladder disorders (esp. cholelithiasis) >2.6-fold, whereas tirzepatide showed no significant biliary risk;...

Safwan M et al., Ann Saudi Med 2025 Source
Full findingIn obesity without diabetes, semaglutide increased gallbladder disorders (esp. cholelithiasis) >2.6-fold, whereas tirzepatide showed no significant biliary risk; neither significantly increased hepatic or pancreatic AEs.
Population13 RCTs, 26,894 obese participants without diabetes; meta-analysis
Fundingacademic/independent - no funding (None)
Scope limitsNotable divergence: biliary signal attached to semaglutide but not tirzepatide in obesity-only; why left open.
Comparatorsplacebo
Semaglutide MARKETED
Safety signals Increase
Very low evidence

VigiBase disproportionality identified a potential signal between semaglutide and bile-duct cancer (cholangiocarcinoma); pancreatic cancer was the most frequent...

Kaur RJ et al., Indian J Gastroenterol 2026 Source
Full findingVigiBase disproportionality identified a potential signal between semaglutide and bile-duct cancer (cholangiocarcinoma); pancreatic cancer was the most frequent neoplasm reported.
PopulationVigiBase ICSRs 1 Jan 2009-31 Jul 2023; disproportionality
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsdisproportionality: reporting != incidence/causality
ComparatorsVigiBase background
Semaglutide MARKETED
Safety signals Increase
Low evidence

Index signal-raising cohort: patients on semaglutide had markedly higher cumulative NAION incidence than those on non-GLP-1 RA medications, in both T2D and...

Hathaway JT et al., JAMA Ophthalmol 2024 Source
Full findingIndex signal-raising cohort: patients on semaglutide had markedly higher cumulative NAION incidence than those on non-GLP-1 RA medications, in both T2D and overweight/obese populations.
PopulationRetrospective matched cohort, single neuro-ophthalmology registry (Mass Eye and Ear); 710 T2D, 979 overweight/obese; Dec 2017-Nov 2023
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitssingle-centre/referral-enriched
Comparatorsnon-GLP-1 RA antidiabetics; non-GLP-1 RA weight-loss meds
Semaglutide MARKETED
Safety signals Increase
Low evidence

Danish nationwide cohort (signal-confirming): once-weekly semaglutide roughly doubled five-year NAION risk in T2D.

Danish cohort, Int J Retina Vitreous 2024 Source
PopulationDanish nationwide registry, 424,152 persons with T2D
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsidentifier not fully verified; single-centre/referral-enriched
Comparatorsnon-semaglutide T2D
Semaglutide MARKETED
Safety signals Mixed
Low evidence

TriNetX global cohort (time-dependent): no NAION increase up to 1 year, but elevated risk at 2-4 years in diabetes.

Hsu AY et al., JAMA Ophthalmol 2025 Source
PopulationTriNetX; 174,584 semaglutide vs 174,584 non-GLP-1 RA with diabetes; Oct 2019-Dec 2023
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsNull early, significant from 2 yr; follow-up length drives the signal. Risk also raised with concomitant hypertension.
Comparatorsnon-GLP-1 RA antidiabetics
Semaglutide MARKETED
Safety signals Decrease
Low evidence

REFUTING/NULL pole: in a large racially diverse Military Health System cohort, semaglutide associated with LOWER odds of NAION in T2D and no significant difference in...

Lieberman RA et al., Mil Med 2026 Source
Full findingREFUTING/NULL pole: in a large racially diverse Military Health System cohort, semaglutide associated with LOWER odds of NAION in T2D and no significant difference in overweight/obesity.
PopulationMilitary Health System beneficiaries; 973,529 T2D + 239,246 overweight/obese; Dec 2017-Sep 2023
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsDirectly contradicts the signal cohorts; authors conclude NAION risk should not preclude use.
Comparatorsnon-GLP-1 RA medications; PDE-5 inhibitors (subset)
Semaglutide MARKETED
Safety signals Increase
Moderate evidence

SIGNAL-confirming meta-analysis (T2D-restricted): semaglutide associated with increased NAION risk vs non-GLP-1RAs, persisting across follow-up windows.

Lampsas S et al., Graefes Arch Clin Exp Ophthalmol 2026 Source
PopulationMeta-analysis; 8 retrospective cohorts (14,255,247 participants), mean age 59.3 yr
Fundingacademic / investigator-initiated; no industry sponsor found in indexed metadata (Europe PMC fundingList empty)
Scope limitsVery high 1-yr heterogeneity (I2 97%). Tensioned against the null class meta-analysis (same year, opposite conclusion, differing inclusion).
Comparatorsnon-GLP-1 RA medications
Semaglutide MARKETED
Safety signals Increase
High evidence

Regulatory: EMA PRAC concluded its review and recommended adding NAION to semaglutide product information as a 'very rare' side effect; WHO issued a confirmatory...

EMA PRAC highlights 2-5 June 2025; WHO safety communication 27 June 2025 Source
Full findingRegulatory: EMA PRAC concluded its review and recommended adding NAION to semaglutide product information as a 'very rare' side effect; WHO issued a confirmatory signal.
PopulationEU regulatory review of all NAION data for semaglutide
Fundingregulatory agency (FDA/EMA/MHRA/WHO)
Scope limitsReview opened Jan 2025, concluded Jun 2025. UK MHRA Drug Safety Update 5 Feb 2026. 'Very rare' sits between high-HR signal studies and null cohorts.
Semaglutide MARKETED
Safety signals Mixed
Moderate evidence

A randomised-trials network meta-analysis found intestinal-obstruction risk not elevated for most GLP-1 agents (liraglutide possibly protective), corroborating the...

Chen JJ et al. Risk of intestinal obstruction with GLP-1 receptor agonists: a randomised-... Source
Full findingA randomised-trials network meta-analysis found intestinal-obstruction risk not elevated for most GLP-1 agents (liraglutide possibly protective), corroborating the weak/very-low post-marketing spontaneous-report obstruction signal.
PopulationRCT network meta-analysis (Chen et al., Int J Mol Sci 2026; the anchor source) of intestinal-obstruction risk across GLP-1 agents, read against the weaker post-marketing spontaneous-report signal.
Fundingacademic/independent - no external funding
Scope limitsnetwork meta-analysis of RCTs for a rare event; obstruction risk not elevated for most agents
Comparatorsplacebo/active comparators in RCTs; post-marketing spontaneous-report background
Semaglutide MARKETED
Safety signals Decrease
Low evidence

Real-world propensity-matched cohort (TriNetX EHR): semaglutide associated with LOWER risk of incident and recurrent suicidal ideation vs non-GLP1R anti-obesity meds;...

Wang W, Volkow ND, Berger NA, Davis PB, Kaelber DC, Xu R. Nat Med 2024;30(1):168-176 Source
Full findingReal-world propensity-matched cohort (TriNetX EHR): semaglutide associated with LOWER risk of incident and recurrent suicidal ideation vs non-GLP1R anti-obesity meds; replicated in T2DM.
Population240,618 overweight/obese (mean 50.1y, 72.6% female); replicated in 1,589,855 T2DM; retrospective cohort emulation, 6-month follow-up
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitspossible confounding by indication
Comparatorsnon-GLP1R anti-obesity medications; non-GLP1R anti-diabetes medications
Semaglutide MARKETED
Safety signals No change
Moderate evidence

Across the STEP programme (RCT data), depression-symptom endorsement on PHQ-9 similar/lower for semaglutide 2.4 mg vs placebo; pooled analysis found no clinically...

Wadden TA et al., JAMA Intern Med 2024 (STEP 1/2/3/5 psychiatric post hoc) Source
Full findingAcross the STEP programme (RCT data), depression-symptom endorsement on PHQ-9 similar/lower for semaglutide 2.4 mg vs placebo; pooled analysis found no clinically meaningful difference in incident significant depressive symptoms and no PHQ-9 worsening.
PopulationPost-hoc analysis of the pooled STEP 1/2/3/5 placebo-controlled RCTs in adults with obesity (PHQ-9 psychiatric-safety endpoints).
Fundingindustry-Novo Nordisk
Scope limitspost-hoc (not prespecified)
Comparatorsplacebo
Semaglutide MARKETED
Safety signals Increase
High evidence

FDA boxed warning: in mice and rats semaglutide caused dose- and treatment-duration-dependent thyroid C-cell tumours (adenomas/carcinomas) at clinically relevant...

Ozempic/Wegovy (semaglutide) US Prescribing Information, FDA Source
Full findingFDA boxed warning: in mice and rats semaglutide caused dose- and treatment-duration-dependent thyroid C-cell tumours (adenomas/carcinomas) at clinically relevant exposures; contraindicated with personal/family history of MTC or MEN 2. Human relevance not determined.
PopulationLifetime rodent carcinogenicity studies; regulatory label
Fundingregulatory agency (FDA/EMA/MHRA/WHO)
Scope limitsanimal data; human relevance uncertain
Comparatorsvehicle control
Semaglutide MARKETED
Safety signals Increase
Very low evidence

FAERS flagged unexpected signals for semaglutide incl. pancreatic cancer, intestinal obstruction (ileus), cholecystitis and polycystic ovary.

Du Y et al., J Diabetes Investig 2024 Source
PopulationFAERS Q1 2018-Q4 2023; disproportionality
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsdisproportionality: reporting != incidence/causality
ComparatorsFAERS background
Semaglutide MARKETED
Safety signals Increase
Low evidence

One year after withdrawal of semaglutide 2.4 mg plus lifestyle intervention, participants regained about two-thirds of lost weight and cardiometabolic improvements...

Wilding JPH et al., Diabetes Obes Metab 2022 Source
Full findingOne year after withdrawal of semaglutide 2.4 mg plus lifestyle intervention, participants regained about two-thirds of lost weight and cardiometabolic improvements reverted towards baseline.
PopulationSTEP 1 trial extension (NCT03548935), off-treatment, n=327 subset, adults without diabetes
Fundingindustry-Novo Nordisk
Scope limitsPer PubMed; numbers CONFIRMED via metadata. Frames obesity as chronic relapsing. Weight-regain straddles safety-other and weight-loss domains.
Comparatorsplacebo
Semaglutide MARKETED
Safety signals Increase
High evidence

Diabetic retinopathy complications significantly more frequent with semaglutide than placebo in SUSTAIN-6 (early-worsening signal).

Marso SP et al. (SUSTAIN-6), NEJM, 2016 Source
PopulationSUSTAIN-6 RCT; 3297 T2D at high CV risk; semaglutide 0.5/1.0 mg vs placebo, 104 weeks
Fundingindustry - Novo Nordisk
Scope limitsconference/abstract-level; magnitude web/secondary-sourced
Comparatorsplacebo
Semaglutide MARKETED
Safety signals Mixed
Very low evidence

Dedicated long-term retinopathy trial (FOCUS) evaluated semaglutide effect on diabetic retinopathy progression over ~5 years.

FOCUS trial, ClinicalTrials.gov Source
PopulationFOCUS RCT, ~1500 T2D with diabetic retinopathy, semaglutide 1.0 mg s.c. weekly vs placebo, ~5 yr
Fundingindustry - Novo Nordisk (trial sponsor; inferred from registration trial)
Scope limitsidentifier not fully verified; no outcome data yet (ongoing)
Comparatorsplacebo
Semaglutide MARKETED
Safety signals Increase
High evidence

In the cardiovascular-outcomes trial, Wegovy-treated patients aged >=75 reported numerically more hip/pelvis fractures than placebo (2.4% vs 0.6%); small numerators,...

Wegovy (semaglutide) US Prescribing Information, Novo Nordisk Source
Full findingIn the cardiovascular-outcomes trial, Wegovy-treated patients aged >=75 reported numerically more hip/pelvis fractures than placebo (2.4% vs 0.6%); small numerators, post-hoc, causality NOT established.
PopulationRegulatory label / SmPC (primary document)
Fundingregulatory agency (FDA/EMA/MHRA/WHO)
Scope limitsregulatory label; reflects approved labelling, not an independent effect estimate
SGLT2 Inhibitor Class (multi-agent) MARKETED
Safety signals Decrease
Moderate evidence

A network meta-analysis of randomised outcome trials found SGLT2 inhibitors significantly reduce incident gout while GLP-1 RAs and DPP-4 inhibitors are neutral - the...

Wang A, Shi W, Zhang N, Tang H, Feng X. Newer glucose-lowering drugs and risk of gout: a ... Source
Full findingA network meta-analysis of randomised outcome trials found SGLT2 inhibitors significantly reduce incident gout while GLP-1 RAs and DPP-4 inhibitors are neutral - the contrast pole showing a genuinely uricosuric, gout-protective class distinct from GLP-1 RAs.
PopulationNetwork meta-analysis (Wang et al., 22 randomised placebo-controlled outcome trials, 173,498 patients with/without T2D).
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsIncluded for the SGLT2i-vs-GLP-1 contrast (the gout-protective comparator pole), not as a GLP-1/retatrutide claim. Indirect (network) comparisons between drug classes; gout a secondary outcome across heterogeneous CVOTs. Academic network meta-analysis.
Comparatorsplacebo; GLP-1 receptor agonist; DPP-4 inhibitor
Tirzepatide MARKETED
Safety signals Not directional
High evidence

Tirzepatide is contraindicated in the US for personal/family history of MTC or MEN 2 (also a boxed warning) and serious hypersensitivity; the EU contraindication is...

Mounjaro (tirzepatide) US Prescribing Information, Eli Lilly; FDA/MHRA/TGA advisories Source
Full findingTirzepatide is contraindicated in the US for personal/family history of MTC or MEN 2 (also a boxed warning) and serious hypersensitivity; the EU contraindication is hypersensitivity only.
PopulationRegulatory label / SmPC (primary document)
Fundingregulatory agency (FDA/EMA/MHRA/WHO)
Scope limitsanimal data; human relevance uncertain
Tirzepatide MARKETED
Safety signals Not directional
High evidence

About half of Mounjaro-treated patients developed anti-tirzepatide antibodies, with low neutralising-antibody rates and no identified clinical impact.

Mounjaro (tirzepatide) US Prescribing Information, Eli Lilly; FDA/MHRA/TGA advisories Source
PopulationRegulatory label / SmPC (primary document)
Fundingregulatory agency (FDA/EMA/MHRA/WHO)
Scope limitsanimal data; human relevance uncertain
Tirzepatide MARKETED
Safety signals Not directional
High evidence

In Zepbound trials the majority of patients developed anti-tirzepatide antibodies; neutralising antibodies were uncommon in the weight-management pool (2.7-2.8%) and...

Zepbound (tirzepatide) US Prescribing Information, Eli Lilly Source
Full findingIn Zepbound trials the majority of patients developed anti-tirzepatide antibodies; neutralising antibodies were uncommon in the weight-management pool (2.7-2.8%) and none were detected in the OSA pool; no clinically significant PK/efficacy effect.
PopulationRegulatory label / SmPC (primary document)
Fundingregulatory agency (FDA/EMA/MHRA/WHO)
Scope limitsregulatory label; reflects approved labelling, not an independent effect estimate
Tirzepatide MARKETED
Safety signals No change
Low evidence

Tirzepatide has no established link to elevated ferritin per trial data and the SmPC, and no known direct effect on iron metabolism; elevated ferritin observed in...

Urbina et al., GLP-1 receptor agonists and iron status, Clin Obes 2026;16:e70070 Source
Full findingTirzepatide has no established link to elevated ferritin per trial data and the SmPC, and no known direct effect on iron metabolism; elevated ferritin observed in users reflects underlying metabolic, inflammatory or liver disease (ferritin as an acute-phase reactant), not a drug effect.
PopulationSynthesised from the Urbina narrative review plus non-measurement of iron in SURPASS/SURMOUNT; tirzepatide iron metabolism not directly studied.
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsMedium confidence; rests partly on a low-quality commercial pharmacy page plus non-measurement of iron in the SURPASS/SURMOUNT programmes. NO commercial/press source minted; anchored as a secondary finding on the Urbina review.
Comparatorsnot applicable
Tirzepatide|semaglutide (head-to-head) MARKETED
Safety signals Mixed
Very low evidence

FAERS comparative disproportionality found acute kidney injury reported LESS frequently with tirzepatide than semaglutide.

Comparative Renal Safety of Tirzepatide and Semaglutide: FAERS Disproportionality Study 2025 Source
PopulationFAERS Jan 2022-Sep 2025, 133,872 reports (92,807 tirzepatide; 41,065 semaglutide)
Fundingacademic/independent analysis (manufacturer not study sponsor; per-study COI not individually audited)
Scope limitsidentifier not fully verified
Comparatorssemaglutide
Tirzepatide MARKETED
Safety signals Mixed
Moderate evidence

Composite gallbladder/biliary disease significantly associated with tirzepatide; pancreatitis and individual biliary endpoints NOT significantly increased.

Zeng Q et al., Front Endocrinol 2023 Source
Population9 RCTs, 9871 participants (T2D and obesity); meta-analysis
Fundingacademic / government - Sichuan Science and Technology Program (China); no industry funding
Scope limitsBoth poles: composite biliary signal present, pancreatitis null.
Comparatorsplacebo; basal insulin; dulaglutide; semaglutide
Tirzepatide MARKETED
Safety signals Decrease
High evidence

Tirzepatide may reduce ORAL hormonal contraceptive efficacy via delayed gastric emptying; US labelling advises switching to a non-oral method or adding a barrier...

Mounjaro (tirzepatide) US Prescribing Information, Eli Lilly; FDA/MHRA/TGA advisories Source
Full findingTirzepatide may reduce ORAL hormonal contraceptive efficacy via delayed gastric emptying; US labelling advises switching to a non-oral method or adding a barrier method for 4 weeks after initiation and after each dose escalation.
PopulationRegulatory label (FDA Mounjaro/Zepbound PI; EU SmPC); PK interaction basis
Fundingregulatory agency (FDA/EMA/MHRA/WHO)
Scope limitsanimal data; human relevance uncertain
Tirzepatide MARKETED
Safety signals No change
Moderate evidence

Post hoc pooled analysis of SURMOUNT-1/-2/-3 (RCT data): no clinically meaningful PHQ-9 difference vs placebo over 72 weeks; suicidal ideation/behaviour (C-SSRS) low...

Wadden TA et al., 'Psychiatric Safety of Tirzepatide... Post Hoc Analysis of SURMOUNT'. O... Source
Full findingPost hoc pooled analysis of SURMOUNT-1/-2/-3 (RCT data): no clinically meaningful PHQ-9 difference vs placebo over 72 weeks; suicidal ideation/behaviour (C-SSRS) low and similar, though a numerically greater percentage of tirzepatide participants reported moderate-risk ideation.
PopulationPooled SURMOUNT-1/-2/-3, obesity, no known major psychopathology; 72 weeks; placebo-controlled RCTs
Fundingindustry-Eli Lilly
Scope limitsRCT-level no-signal pole. The numerically-greater moderate-risk SI on tirzepatide recorded as the emerging caveat, neither amplified nor suppressed.
Comparatorsplacebo
Tirzepatide MARKETED
Safety signals Increase
High evidence

FDA boxed warning: in a 2-year rat study tirzepatide caused dose- and treatment-duration-dependent thyroid C-cell tumours at clinically relevant exposures;...

Mounjaro (tirzepatide) US Prescribing Information, Eli Lilly; FDA/MHRA/TGA advisories Source
Full findingFDA boxed warning: in a 2-year rat study tirzepatide caused dose- and treatment-duration-dependent thyroid C-cell tumours at clinically relevant exposures; contraindicated with personal/family history of MTC or MEN 2. Human relevance not determined.
Population2-year rat carcinogenicity study; regulatory label
Fundingregulatory agency (FDA/EMA/MHRA/WHO)
Scope limitsanimal data; human relevance uncertain
Comparatorsvehicle control
Tirzepatide MARKETED
Safety signals Decrease
Moderate evidence

In a network meta-analysis, tirzepatide produced the greatest reduction in both fat mass and (absolute) lean body mass.

Rakhsha SS et al., Diabetes Obes Metab 2026 Source
PopulationNetwork meta-analysis, 41 RCTs, 2906 participants, through Mar 2025
Fundingacademic - Tehran University of Medical Sciences (Chronic Diseases Research Center; grant 1403-04-75722-221); no industry sponsor
Scope limitsLargest LBM reduction of class, proportionate to larger total weight loss. Exercise reported to mitigate.
Comparatorsplacebo; semaglutide; liraglutide; SGLT2i; metformin; insulin; DPP-4i
Tirzepatide MARKETED
Safety signals Increase
Moderate evidence

Withdrawing tirzepatide after a 36-week lead-in led to substantial weight REGAIN, whereas continued treatment maintained/augmented loss (randomized-withdrawal design).

Aronne LJ et al., JAMA 2024 (SURMOUNT-4) Source
PopulationSURMOUNT-4 (NCT04660643), phase 3 randomized-withdrawal, 670 adults with obesity/overweight (no diabetes), 52-wk double-blind after open-label lead-in
Fundingindustry-Eli Lilly
Scope limitsopen-label (unblinded)
Comparatorsplacebo (withdrawal)
Tirzepatide MARKETED
Safety signals Decrease
Moderate evidence

In a post hoc analysis of the SURMOUNT-1 obesity RCT, tirzepatide lowered serum uric acid dose-dependently versus placebo over 72 weeks, with the effect independent of...

Sattar N et al. Tirzepatide and change in uric acid and its association with weight reduc... Source
Full findingIn a post hoc analysis of the SURMOUNT-1 obesity RCT, tirzepatide lowered serum uric acid dose-dependently versus placebo over 72 weeks, with the effect independent of baseline uric-acid level or BMI.
PopulationTirzepatide phase-3 obesity RCT post hoc (Sattar et al., SURMOUNT-1, NCT04184622); 2,539 adults with obesity/overweight + >=1 weight-related complication.
Fundingindustry - Eli Lilly (trial sponsor; inferred from registration trial)
Scope limitsPost hoc (not a prespecified gout/urate endpoint); biochemical surrogate (SUA), not a clinical gout outcome. Lilly-sponsored trial. The drop is real and dose-dependent but - see C-TIRZ-URATE-02 - largely weight-mediated.
Comparatorsplacebo
Tirzepatide MARKETED
Safety signals Decrease
Moderate evidence

A mediation analysis in the same SURMOUNT-1 post hoc found that about 73% of tirzepatide's serum-uric-acid reduction was explained by weight loss - implicating weight...

Sattar N et al. Tirzepatide and change in uric acid and its association with weight reduc... Source
Full findingA mediation analysis in the same SURMOUNT-1 post hoc found that about 73% of tirzepatide's serum-uric-acid reduction was explained by weight loss - implicating weight loss rather than a direct uricosuric drug effect.
PopulationTirzepatide phase-3 obesity RCT post hoc (Sattar et al., SURMOUNT-1, NCT04184622); mediation analysis of weight change vs SUA change.
Fundingindustry - Eli Lilly (trial sponsor; inferred from registration trial)
Scope limitsASSOCIATIONAL mediation, NOT a designed causal endpoint - the 72.7% weight-mediated figure is a model decomposition, not a randomised mechanistic test. Confounded with all weight-loss-correlated changes. Supports the weight-mediated (not direct-uricosuric) reading of the class.
Comparatorsplacebo
Aleniglipron INVESTIGATIONAL
Safety signals No change
Moderate evidence

No drug-induced liver injury events reported in the phase 2b trial.

Rosenstock J et al. Oral small molecule GLP-1 receptor agonist aleniglipron in people wit... Source
PopulationACCESS phase 2b (NCT06693843); 36 wk
Fundingindustry - Structure Therapeutics (via subsidiary Gasherbrum Bio, Inc.)
Scope limitssmall sample (N~230)
Comparatorsplacebo
Danuglipron INVESTIGATIONAL
Safety signals Increase
Very low evidence

Drug-induced liver injury signal leading to program discontinuation.

Pfizer press release: Pfizer Provides Update on Oral GLP-1 Receptor Agonist Danuglipron, ... Source
PopulationPfizer dose-optimisation program (post phase 2b); chronic weight management
Fundingindustry - Pfizer (trial sponsor; inferred from registration trial)
Scope limitsDiscontinuation driver. Single-case hepatotoxicity vs class-typical aggregate LFTs is the central tension (recorded neutrally, no verdict). Press-sourced.
Lotiglipron INVESTIGATIONAL
Safety signals Increase
Very low evidence

Elevated liver enzymes observed in clinical testing, leading to discontinuation of the entire program in 2023.

Pfizer / BioPharma Dive: Pfizer, citing safety concerns, scraps one of two obesity pill h... Source
PopulationPfizer phase 1/2 lotiglipron program (obesity and T2D)
Fundingindustry - Pfizer (trial sponsor; inferred from registration trial)
Scope limitsidentifier not fully verified
Pramlintide MARKETED
Safety signals Increase
High evidence

Boxed warning for insulin-induced severe hypoglycaemia; requires mealtime-insulin dose reduction

SYMLIN FDA label 2015 Source
PopulationT1D/T2D on mealtime insulin
Fundingregulatory agency (FDA/EMA/MHRA/WHO)
Scope limitsHypoglycaemia is insulin-co-administration effect, not amylin-intrinsic
Comparatorsplacebo + insulin
Survodutide INVESTIGATIONAL
Safety signals No change
Moderate evidence

Serious adverse events comparable to placebo; no safety signal attributed to glucagon receptor agonism

Sanyal AJ et al. A Phase 2 Randomized Trial of Survodutide in MASH and Fibrosis. N Engl J... Source
PopulationMASH phase 2 (n=293), 48 wk
Fundingindustry - Boehringer Ingelheim / Zealand
Scope limitsSYNCHRONIZE phase 3 CV outcomes trial ongoing
Comparatorsplacebo
TERN-601 MARKETED
Safety signals Increase
Very low evidence

Reversible grade-3 liver enzyme elevations in the phase 2 follow-up period.

Terns Pharmaceuticals press release, 21 Oct 2025. Source
PopulationFALCON phase 2 (obesity/overweight); post-treatment follow-up
Fundingindustry - Terns (trial sponsor; inferred from registration trial)
Scope limitsidentifier not fully verified; small sample (N~30)
Comparatorsplacebo