GLP-1 Evidence

Not medical advice. A record of published research and our assessments of it. The limits

GLP-1 Receptor Agonists and the Risk of Thyroid Cancer

Design
Case-control · 47746 participants · Hard outcome
Match to healthy normal-weight adults aged 55–75
Different populationType 2 diabetes; French claims data.
Could weight loss explain it?
Unknown[Auto] Harm signal; weight-loss mediation not the relevant question, but consider whether harms relate to rapid weight loss or reduced intake.
Study tier
Study tier 4Nested case-control with plausible detection bias; contradicted by a larger active-comparator cohort.
Assessment
Version 2 · curated · Sep 13, 2026

Study facts come from the paper. Population match, weight-loss explanation and study tier are our judgments, made against the reference group of healthy normal-weight adults aged 55–75.

A French case-control study found about 60% higher thyroid cancer risk after 1-3 years of GLP-1 use in people with diabetes. Detection bias is a concern, and a larger Scandinavian cohort found no increase.

01Findings

What the study reported

Drugs
Class unspecified
Primary outcome
Thyroid cancer (nested case-control, French SNDS)
Effect
1-3 years use: all thyroid cancer aHR 1.58; medullary aHR 1.78
95% confidence interval
1.27 to 1.95; 1.04 to 3.05
Follow-up
6 years
Adverse events
Not extracted
Limitations
Auto-classified from abstract only; effect estimates, adverse events and limitations not extracted. Requires manual review.

Who was studied

Diabetes status
type 2 diabetes on second-line drugs

Study quality details

Study design
Case-control
Sample size
not extracted
Randomization
no
Blinding
not stated
Comparator
not stated
Follow up duration
6 years
Outcome type
unknown
Replication
not assessed (auto)
Consistency with other evidence
not assessed (auto)
Population applicability
INDIRECT
Statistical precision
moderate
Risk of bias
detection bias plausible (more thyroid imaging in GLP-1 users); claims-based diagnoses
Funding conflicts
unclear
Peer review status
yes
02Funding

Funding and conflicts

Funding
Non-US government (per PubMed)
Industry funded
No
Manufacturer
None identified
Sponsor role
not reported in abstract
Author conflicts
See published disclosures.
Independent replication
no; contradicted

Funding is shown on every study and never used to score it.

03Claims

Claims this study bears on

04Source

The source, as retrieved

Abstract

[OBJECTIVE] To determine whether use of glucagon-like peptide 1 (GLP-1) receptor agonists (RA) is associated with increased risk of thyroid cancer. [RESEARCH DESIGN AND METHODS] A nested case-control analysis was performed with use of the French national health care insurance system (SNDS) database. Individuals with type 2 diabetes treated with second-line antidiabetes drugs between 2006 and 2018 were included in the cohort. All thyroid cancers were identified through hospital discharge diagnoses and medical procedures between 2014 and 2018. Exposure to GLP-1 RA was measured within the 6 years preceding a 6-month lag-time period and considered as current use and cumulative duration of use based on defined daily dose (≤1, 1 to 3, >3 years). Case subjects were matched with up to 20 control subjects on age, sex, and length of diabetes with the risk-set sampling procedure. Risk of thyroid cancer related to use of GLP-1 RA was estimated with a conditional logistic regression with adjustment for goiter, hypothyroidism, hyperthyroidism, other antidiabetes drugs, and social deprivation index. [RESULTS] A total of 2,562 case subjects with thyroid cancers were included in the study and matched with 45,184 control subjects. Use of GLP-1 RA for 1-3 years was associated with increased risk of all thyroid cancer (adjusted hazard ratio [HR] 1.58, 95% CI 1.27-1.95) and medullary thyroid cancer (adjusted HR 1.78, 95% CI 1.04-3.05). [CONCLUSIONS] In the current study we found increased risk of all thyroid cancer and medullary thyroid cancer with use of GLP-1 RA, in particular after 1-3 years of treatment.

Where this record came from

SourceRetrievedIdentifier
pubmedSep 13, 202636356111
first ingestion