A large retrospective study found no increased 5-year thyroid cancer risk in type 2 diabetes patients taking GLP-1 receptor agonists compared to those on other common diabetes medications.
No increased riskGLP-1RA users had thyroid cancer rates of 0.25–0.33% over 5 years, numerically lower than all three comparator drug groups
What the researchers found
Patients with type 2 diabetes taking GLP-1 receptor agonists showed no statistically significant increase in 5-year thyroid cancer risk compared to those taking three other common diabetes drug classes.
GLP-1RA vs SGLT-2 inhibitors (7,736 per group): thyroid cancer rate 0.30% vs 0.48%, RR 0.62 (95% CI 0.37–1.05, P=.07). GLP-1RA vs metformin (5,158 per group): 0.25% vs 0.39%, RR 0.65 (95% CI 0.32–1.31, P=.22). GLP-1RA vs DPP-4 inhibitors (12,570 per group): 0.33% vs 0.37%, RR 0.91 (95% CI 0.60–1.39, P=.67).
In all three comparisons, thyroid cancer rates were numerically lower in the GLP-1RA group, though none reached statistical significance.
Why it matters
Millions of people now take GLP-1 receptor agonists for diabetes and weight loss, and thyroid cancer has been a safety concern flagged in animal studies and drug labels. This large real-world study provides reassuring evidence that these widely prescribed medications may not increase thyroid cancer risk over five years, though longer follow-up is still needed.
How the study worked
This was a retrospective cohort study using the TriNetX database, identifying type 2 diabetes patients between 2017 and 2019. Researchers compared thyroid cancer rates over 5 years between patients taking GLP-1 receptor agonists and those taking three alternative diabetes medications (SGLT-2 inhibitors, metformin, and DPP-4 inhibitors). Propensity score matching was used to control for differences in demographics and comorbidities between groups.
What this study cannot tell us
As a retrospective database study, it cannot establish causation. The 5-year follow-up may be too short to detect cancers with long latency periods. The TriNetX database may have coding inconsistencies or missing data. Most GLP-1 receptor agonists were approved within the last decade, so long-term effects beyond 5 years remain unknown. The study also could not distinguish between specific GLP-1RA drugs or account for duration of use.
How to read the evidence
This is a large retrospective cohort study with propensity score matching, providing moderate-quality evidence. It is strengthened by its large sample sizes and multiple comparator groups, but limited by its observational design and relatively short follow-up period.
When this study was published
Published in 2026, this is very recent research addressing a timely safety concern about one of the most widely prescribed drug classes.
The bigger picture
GLP-1 receptor agonists are among the fastest-growing drug classes globally, prescribed for both type 2 diabetes and obesity. Early animal studies raised thyroid cancer concerns, leading to boxed warnings on some product labels. As real-world data accumulates from millions of patients, studies like this help clarify whether those preclinical signals translate into actual human risk — a critical question for public health given the scale of GLP-1RA prescribing.
Questions still open
- Would a longer follow-up period of 10-20 years reveal different thyroid cancer risk patterns with GLP-1 receptor agonists?
- Do specific GLP-1RA drugs carry different levels of thyroid cancer risk compared to others in the class?
- Does the dose or duration of GLP-1RA use affect thyroid cancer risk differently than simple exposure?
Common questions
Do GLP-1 drugs like Ozempic or Wegovy cause thyroid cancer?
Why is there a thyroid cancer warning on GLP-1 receptor agonist labels?
Read the original research
Thyroid Cancer Risk in Patients With Type 2 Diabetes Taking Glucagon-Like Peptide 1 Receptor Agonists.
OTO open, 10(1), e70188
Citation
Sciscent, Bao Y; Eberly, Hanel W; Lorenz, F Jeffrey; Goldrich, David; Goyal, Neerav; Goldenberg, David. (2026). Thyroid Cancer Risk in Patients With Type 2 Diabetes Taking Glucagon-Like Peptide 1 Receptor Agonists.. OTO open, 10(1), e70188. https://doi.org/10.1002/oto2.70188