Study summary

Across drug trials, GLP-1 medicines were linked to a small rise in thyroid cancer

GLP-1 trials review · 64 randomized trials · Published November 2023, Diabetes, Obesity and Metabolism

What was tested

A pooled look at 64 randomized trials of GLP-1 medicines such as semaglutide and liraglutide, lasting at least a year, counting every thyroid cancer diagnosed.

What they found

• People on GLP-1 medicines had about 1.5 times the relative risk of a thyroid cancer diagnosis.
• In absolute terms, about 1 extra thyroid cancer for every 1,349 people treated for 5 years.
• The result was borderline: moving 1 case would erase it, and it was not significant for papillary or medullary cancer alone.

What it means

A small signal that may partly reflect more thyroid checks in people on these drugs. Larger real-world studies are more reassuring.