A multinational study presented at the European Academy of Dermatology and Venereology Congress 2026 found that people taking GLP-1 medications were more than four times as likely to report nail detachment, a condition in which the nail separates from the skin beneath it. It is the first controlled study to look at the question rather than collecting one-off case reports.

The drugs involved include semaglutide (Ozempic and Wegovy), tirzepatide (Mounjaro and Zepbound), liraglutide (Victoza) and dulaglutide (Trulicity). They act on a hormone signaling system that helps regulate blood sugar and appetite, which is why they have become standard tools for obesity and type 2 diabetes.

Key results

Researchers compared 575 GLP-1 users with 1,329 people who had type 2 diabetes and/or obesity but had never taken the drugs, recruited in France, the United States, Brazil and Mexico. Nail detachment was reported by 39% of users versus 9% of never-users, discoloration by 46% versus 17%, and at least one nail disorder by 66% versus 53%.

A companion study of the same participants found half of GLP-1 users reporting unusual hair loss, compared with 34% of nonusers, and reduced hair volume in 42% versus 19%. Scalp redness was roughly three times more frequent.

The weight-loss explanation does not fully hold

The obvious counter-argument is that rapid weight loss alone disturbs nutrition and physiology enough to affect nails and hair. The researchers tested it, and when they restricted the analysis to participants who had lost weight, GLP-1 users still reported significantly more nail problems.

The hair findings point the same way. Shedding rarely appeared alone, usually arriving with itching, redness or flaking, which led study author Dr. Bruno Halioua to say the scalp changes "may go beyond the classical shedding seen after rapid weight loss and involve an inflammatory component."

Limitations

Both investigations were cross-sectional and relied on symptoms participants reported themselves rather than standardized clinical exams. About half of the medication users said they had nail problems before starting treatment, and adjusting for existing skin conditions and nutritional deficiencies shrank some gaps, though detachment and discoloration stayed two to three times more common.

Study author Dr. Charles Taieb put it directly: the findings show a clear association, but "not everything that happens during GLP-1 treatment is necessarily caused by the treatment itself." The work received institutional support from DUCRAY Laboratories, part of the Pierre Fabre Group, which sells dermatological and hair care products.

Where the research goes next

The team plans prospective studies following patients from the start of treatment, with standardized skin, hair and nail examinations plus biological monitoring. The open questions are when the changes appear, what drives them, and whether they fade on their own.