New research suggests that GLP-1 medications used to treat obesity and diabetes are associated with a slightly higher risk of hair loss, although the condition remains rare overall.
The findings come from three separate studies examining patients taking GLP-1 receptor agonists, including semaglutide (sold as Wegovy and Ozempic) and tirzepatide (marketed as Zepbound and Mounjaro).
Higher risk, but uncommon
A study led by researchers at the University of Pennsylvania, published in The BMJ, found that after two or more years of treatment, people using GLP-1 drugs had:
- 37% higher odds of developing alopecia than users of SGLT-2 diabetes medications.
- 68% higher odds compared with users of DPP-4 inhibitors.
Despite the increase, the overall number of cases remained low, with approximately three to nine new cases per 1,000 people each year.
Similar findings in other research
Another study involving more than one million participants worldwide, published in the Journal of the American Academy of Dermatology, also found higher rates of several forms of alopecia among GLP-1 users compared with patients taking metformin.
A third study by analytics company nference compared more than 11,000 patients taking tirzepatide with an equal number using semaglutide.
Researchers found new-onset alopecia occurred in:
- 4.24% of patients taking tirzepatide.
- 3.33% of patients taking semaglutide.
Among women, the difference was more pronounced:
- 5.44% with tirzepatide.
- 3.63% with semaglutide.
Weight loss may not be the only factor
Hair loss is a recognised side effect that can accompany significant weight loss and is often temporary and reversible.
However, researchers said the higher risk associated with tirzepatide remained even after accounting for the amount of weight patients lost or the dosage they received.
The study also found alopecia was more common among patients with thyroid disease or other endocrine disorders, suggesting hormonal or autoimmune factors may contribute to the increased risk.
Researchers said the findings support personalised counselling and monitoring rather than assuming hair loss is solely caused by rapid weight loss.
