A multinational study has linked GLP-1 medications — including Ozempic, Wegovy, Mounjaro, Zepbound, Victoza and Trulicity — to unexpectedly frequent nail problems. Among 575 users and 1,329 people with type 2 diabetes and/or obesity who had never taken the drugs, 39% of users reported nail detachment, in which the nail separates from the skin beneath it, compared with 9% of nonusers. Two-thirds of users reported at least one nail disorder versus 53% of controls, and nail discoloration affected 46% of users against 17% of nonusers. Participants were recruited from France, the United States, Brazil and Mexico. The findings, presented at the European Academy of Dermatology and Venereology Congress 2026, come from what the researchers describe as the first controlled study of the possible relationship.
The team tested whether weight loss itself might explain the pattern, since rapid weight change can affect nutrition and other processes that influence nails and hair. Restricting the analysis to participants who had lost weight, GLP-1 users still reported significantly more nail problems. The results do not prove the drugs cause these disorders: roughly half of the medication users said they had experienced nail problems before starting treatment, and adjusting for existing skin conditions and nutritional deficiencies narrowed some differences. Nail detachment and discoloration nonetheless remained about two to three times more common among users. "Our findings show a clear association, but they also underline an important point: not everything that happens during GLP-1 treatment is necessarily caused by the treatment itself," said study author Dr. Charles Taïeb.
A companion study of the same participants found similar gaps in hair and scalp health. Half of GLP-1 users reported unusual hair loss, compared with 34% of nonusers, and reduced hair volume or density affected 42% of users versus 19%. Hair loss that began after treatment started was reported by 26% of users and 12% of nonusers, and scalp redness was roughly three times as frequent among users. Shedding rarely occurred on its own; most users who reported it also had itching, redness or flaking skin, which the researchers say points to inflammation rather than rapid weight loss alone. "Scalp inflammation was the rule rather than the exception, which clinicians do not currently look for and which may be treatable," said study author Dr. Bruno Halioua.