Health

Study Links Weight Loss Drugs to Hair Loss Risk

Are GLP-1s a manageable trade-off or are patients not being warned of the side effects?

Published JUL 23

Study Links Weight Loss Drugs to Hair Loss Risk

Story

Above: A group of weight loss injection pen medications. Image credit: Michael Siluk/UCG/Universal Images Group/Getty Images

The Facts

A study published in The BMJ on Wednesday found that GLP-1 receptor agonist drugs — including semaglutide (Ozempic and Wegovy) and tirzepatide (Mounjaro) — were associated with a 37% higher risk of alopecia than SGLT-2 inhibitors and a 68% higher risk than DPP-4 inhibitors.
BMJ
Independent
Reuters
The study, led by researchers at the University of Pennsylvania, used electronic health records from January 2019 to September 2024, comparing 12,004 GLP-1 drug users with 15,221 SGLT-2 inhibitor users and 11,964 GLP-1 users with 11,233 DPP-4 inhibitor users.
BMJ
ScienceAlert
Daily Mail
The elevated hair loss risk was specific to non-scarring alopecia, in which hair follicles remain intact and regrowth is possible, as GLP-1 users showed a 53% and 72% higher risk than SGLT-2 and DPP-4 inhibitor users, respectively.
MedPage Today
News Medical
Daily Mail
Researchers said the most likely mechanism behind hair loss in GLP-1 users relates to weight loss and reduced caloric intake, which may cause micronutrient deficiencies — such as of iron, zinc and biotin — that disrupt the hair growth cycle.
RTE.ie
Medicalxpress
The Telegraph
The absolute rate of alopecia among GLP-1 users remained low, ranging from roughly 3 to 9 per 1,000 people per year. Researchers noted the findings may still influence patients' decisions to start or continue therapy.
Sky News
People
The Telegraph
The U.K.'s Medicines and Healthcare products Regulatory Agency has received 399 reports of hair loss linked to tirzepatide so far in 2026, alongside 541 in the prior year, and 148 reports tied to semaglutide, alongside 164 the year before.
RTE.ie
Independent
Daily Mail

Sources Split

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The Spin

Narrative A

This study provides valuable evidence that weight-loss drugs increase the risk of non-scarring hair loss. However, hair loss from GLP-1 drugs is just one piece of a much uglier picture — rapid fat loss also destroys facial volume, accelerates visible aging and causes muscle wasting that no one is warning patients about upfront. These are powerful medications with real consequences, especially for people using them for modest weight loss goals.

Camus on X

Dr. Gabrielle Lyon on X

Narrative B

Although methodologically robust, this observational study cannot establish causation, leaving residual confounding and alternative explanations unresolved. While GLP-1 receptor agonists were linked to a higher relative risk of non-scarring hair loss, the absolute increase was small — only two to three additional cases per 1,000 person-years. The findings warrant awareness but should not overshadow the therapies' proven metabolic and cardiovascular benefits.

Science Media Centre