GLP-1 receptor agonists increase the risk of thyroid cancer in humans.
- Current status
- ContradictoryEvidence weakening · Cancer
- Why
- Rodent C-cell tumours underlie the boxed warning. A French case-control analysis found increased thyroid and medullary cancer with 1-3 years' use, but a larger Scandinavian active-comparator cohort found no increase (HR 0.93, upper CI 1.31). Detection bias is a concern in the positive study; follow-up remains short for a slow-growing cancer.
- What would change it
- Longer-follow-up registry data (10+ years) or a medullary-thyroid-cancer-specific signal in independent cohorts.
- Linked studies
- 2 · 1 supports · 1 contradicts
- Last updated
- Sep 13, 2026
The status is the collection's own judgment on its assessment scale, not a GRADE certainty rating and not medical advice.
01The evidence
The evidence, sorted by what it shows
Supports (1)
- GLP-1 Receptor Agonists and the Risk of Thyroid CancerCase-control · 2023 · Study tier 4 · Different population · Harm direction
SNDS nested case-control: aHR 1.58 all thyroid cancer, 1.78 medullary, for 1-3 years' use.
Contradicts (1)
- Glucagon-like peptide 1 receptor agonist use and risk of thyroid cancer: Scandinavian cohort studyRetrospective cohort · 2024 · Study tier 3 · Different population · Null · Partly industry funded
Scandinavian cohort, 145,410 users: HR 0.93 (0.66-1.31) vs DPP-4 inhibitors.
02History
How this assessment has changed
- ContradictorySep 13, 2026 · Evidence weakening
initial curated status