In nearly 90,000 patients followed for a median of 4.5 years, long-term GLP-1 receptor agonist use was not associated with increased thyroid cancer risk.
89,646 patientsLarge propensity-matched cohort showing no increased thyroid cancer risk with GLP-1 RA use
What the researchers found
No increased thyroid cancer risk was found in 89,646 GLP-1 RA users followed for a median of 4.5 years compared to matched controls on other diabetes drugs.
Why it matters
This is one of the largest and longest studies to address the thyroid cancer concern, providing meaningful safety reassurance for millions of GLP-1 users.
The numbers in context
N=89,646; median follow-up 4.5 +/- 2.3 years; no increased thyroid cancer risk vs insulin, metformin, SGLT2i, DPP-4i, sulfonylureas, or thiazolidinediones.
How the study worked
Propensity score matched cohort study using TriNetX electronic health records (2014-2020) with active comparator controls.
Who was studied
Adults with type 2 diabetes who initiated GLP-1 RA therapy (2014-2020)
What this study cannot tell us
Observational design — cannot fully exclude residual confounding. Electronic health records may have coding inconsistencies.
How to read the evidence
Large propensity-matched cohort with active comparators — strong observational evidence, though not a randomized trial.
When this study was published
Published in 2025, providing the most current large-scale thyroid cancer safety data for GLP-1 drugs.
The bigger picture
This large-scale evidence should help resolve lingering fears about thyroid cancer that have affected both prescribing decisions and patient acceptance.
Questions still open
- Does the safety signal hold for newer GLP-1 drugs not included in this period?
- Are specific GLP-1 agents safer than others regarding thyroid risk?
Common questions
Do GLP-1 drugs cause thyroid cancer?
Why was there concern about thyroid cancer and GLP-1 drugs?
Read the original research
Long-Term Glucagon-Like Peptide 1 Receptor Agonist Use Is Not Associated With Increased Risk of Thyroid Cancer in Adults With Type 2 Diabetes.
Diabetes/metabolism research and reviews, 41(8), e70104
Citation
Pollack, Rena; Stokar, Joshua. (2025). Long-Term Glucagon-Like Peptide 1 Receptor Agonist Use Is Not Associated With Increased Risk of Thyroid Cancer in Adults With Type 2 Diabetes.. Diabetes/metabolism research and reviews, 41(8), e70104. https://doi.org/10.1002/dmrr.70104