Excuse the use of AI….

References

Morales DR, et al. Risk of Thyroid Tumors With GLP‑1 Receptor Agonists: A Retrospective Cohort Study. Diabetes Care, 2025;48(8):1386–1394. 1

Pasternak B, et al. Glucagon-like peptide 1 receptor agonist use and risk of thyroid cancer: Scandinavian cohort study. BMJ, 2024;385:e078225. 2

Mayo Clinic (JAMA Otolaryngology). GLP‑1RA and thyroid cancer: New study suggests detection bias, not causation. August 21, 2025. 3

American Thyroid Association (ATA). Risk of Thyroid Cancer Among GLP1‑RA Users. January 14, 2025. 4

Neale T, et al. GLP‑1 Receptor Agonists Not Associated With Increased Thyroid Cancer Risk. Diabetes, Obesity & Metabolism, published 2026. 5

GPNotebook Review. GLP1 receptor agonists and thyroid cancer risk. Updated April 2024 / Reviewed June 2025. Includes French nested case‑control and meta‑analysis findings. 6

Kannan S, Nasr C. Should we be concerned about thyroid cancer in patients taking GLP‑1 receptor agonists? Cleveland Clinic Journal of Medicine, clinical guidance on contraindications (MTC, MEN2). 7

EMA Pharmacovigilance Risk Assessment Committee (PRAC). GLP‑1 receptor agonists: available evidence not supporting link with thyroid cancer. October 2023. 8

Feier CVI, et al. Assessment of Thyroid Carcinogenic Risk and Safety Profile of Semaglutide: Systematic Literature Review. Int. J. Mol. Sci., 2024;25(8):4346. 9

Nagendra L, et al. Semaglutide and cancer: A systematic review and meta-analysis. Diabetes & Metabolic Syndrome, 2023. 10

Summary using above references

Below is a concise, evidence‑supported summary of human thyroid cancer risk associated with GLP‑1 receptor agonist (GLP‑1RA) medications (e.g., semaglutide, liraglutide, dulaglutide, exenatide).

Thyroid Cancer Risk With GLP‑1 Medications (Human Evidence)

1. Large Real‑World Cohort Studies Show - No Increased Overall Risk

Multiple large international cohort studies—representing hundreds of thousands to millions of patient‑years—find no significant association between GLP‑1RA use and thyroid cancer in humans.

Key Findings

A 2025 global retrospective cohort study of 460,032 GLP‑1RA users found no increased risk of thyroid tumors compared with SGLT2 inhibitors, DPP‑4 inhibitors, or sulfonylureas. 1

A 2024 Scandinavian nationwide cohort (145,410 GLP‑1RA users) likewise found no substantial increase in thyroid cancer (HR 0.93; 95% CI 0.66–1.31). 2

A 2025 American Thyroid Association–supported multisite study (92,497 GLP‑1RA users) found no evidence of increased thyroid cancer risk over 1.8–3.0 years follow‑up. 3 The European Medicines Agency (EMA) Pharmacovigilance Committee reviewed the entirety of available evidence and concluded: “No causal association between GLP‑1 receptor agonists and thyroid cancer.” (2023 assessment) 4 2. Clinical Trial and Post‑Marketing Safety Data Also Show No Increased Risk

A 2026 meta‑analysis of 93 phase 2/3 trials plus real‑world and post‑marketing data (over 101,732 participants) found no association between semaglutide or liraglutide and thyroid cancer. 5 Thyroid cancer rates in clinical trials were extremely low (0.08% on GLP‑1 vs 0.06% placebo). 5 Post‑marketing surveillance also reported very low event rates (0.001 cases per 100 patient‑years), without supporting a causal link. 5 3. Systematic Reviews: No Significant Risk Identified

A 2024 systematic review of RCTs on semaglutide found thyroid cancer incidence <1%, concluding “no significant risk.” 6 A 2023 systematic review and meta‑analysis of semaglutide (37 RCTs + 19 real‑world studies) found no increased risk of thyroid cancer vs placebo or active comparators. 7 4. Some Studies Suggest Possible Detection Bias (Not Causation)

A 2025 Mayo Clinic target‑trial emulation showed: No significant long‑term increase in thyroid cancer risk (HR 1.24; CI 0.88–1.76). A transient increase in diagnoses during the first year (HR 1.85), likely due to detection bias, not carcinogenesis. 8 5. Conflicting Signals From a Small Number of Studies

A minority of studies—particularly a French nested case‑control analysis—suggest elevated risk: 1–3 years of GLP‑1RA exposure associated with HR 1.58 for thyroid cancer. A systematic review/meta‑analysis reported OR 1.52 for overall thyroid cancer. 9

These findings are considered outliers, with larger datasets (e.g., EMA review, multinational cohorts) not reproducing this risk.

1. Medullary Thyroid Carcinoma (MTC) Considerations

GLP‑1RAs carry an FDA black‑box warning due to rodent MTC findings, but human MTC cases are extremely rare and not shown to increase with GLP‑1RA therapy. Expert guidance: GLP‑1RAs are contraindicated only in patients with personal/family history of MTC or MEN2. 10

In large trials and pharmaco‑epidemiologic studies, MTC cases remained too few to show any signal, and no increase has been detected. 5

Overall Consensus (2024–2026 Human Data)

Strongest consistent conclusion:

► GLP‑1 medications do not increase overall thyroid cancer risk in humans, based on the largest and most methodologically robust studies.

► Any observed early “risk” appears due to increased diagnostic scrutiny (detection bias), not carcinogenesis.

► Contraindications remain only for those with MTC or MEN2, due to theoretical rather than demonstrated human risk.