Nearly two-thirds of people taking GLP-1 medications reported at least one nail disorder — a 13-point jump over people who never used the drug class — according to a study presented at the European Academy of Dermatology and Venereology Congress 2026.

The researchers compared health data from 575 people in the U.S., France, Brazil, and Mexico who used GLP-1 receptor agonists such as semaglutide (Ozempic and Wegovy) and tirzepatide (Mounjaro and Zepbound) against 1,329 people with type 2 diabetes or obesity who had never taken the medications.

The numbers get starker at the symptom level. Nail detachment — onycholysis, the separation of the nail from the nail bed, per the Cleveland Clinic — affected 39% of GLP-1 users versus 9% of controls. Nail discoloration affected 46% of users versus 17% of controls.

The study found an association, not proof of causation. "Until now, nail changes associated with GLP-1 therapies had essentially been anecdotal," study co-author Charles Taïeb, MD, a dermatologist at Necker University Hospital in Paris, said in a statement. "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."

Clinicians say the pattern matches what they see in practice. Many GLP-1 side effects trace back to weight loss rather than the drugs. Here, that explanation falls short: the rate of nail problems ran higher among GLP-1 users regardless of how much weight they lost, pointing toward a more direct effect — though the study authors caution more research is needed.

Nail issues after weight loss are not new. "This is uncommon overall, but we do see it with our surgical weight loss patients as well," says Mir Ali, MD, medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, CA. Dr. Ali agrees, however, that nail detachment "seems to be independent of the weight lost," based on both the findings and his own patients.

Ife J. Rodney, MD, founding director of Eternal Dermatology + Aesthetics in the Baltimore-Washington metropolitan area, calls the elevated detachment risk "not surprising." She compares it to the hair loss seen with GLP-1 use, driven by weight loss and genetic factors. Nails and hair both consist primarily of the protein keratin, and protein intake often drops on GLP-1s because appetite shrinks — a frequent concern for prescribers.

Nutritional deficiency is the leading suspect. GLP-1 users typically consume fewer calories, making it harder to reach thresholds for protein, iron, and B vitamins, all of which support nail growth, according to Dr. Ali.

"As a result, your body may not produce nail plates as efficiently or may even stop producing the nails temporarily," which leads to breakage and detachment, Dr. Rodney says. "It's not that GLP-1s are directly toxic to the nails, but the body has other concerns outside the nails when you're in this state of nutritional deficiency."

Detachment warrants a professional evaluation. "A true nail detachment warrants a visit to your dermatologist to make sure there is no infection or inflammation," says Gary Goldenberg, MD, assistant clinical professor of dermatology at Icahn School of Medicine at Mount Sinai Hospital in New York City.

The differential matters. Other medications — including the antibiotic tetracycline and oral retinoids like Accutane — plus underlying thyroid disease can also detach nails, so identifying the driver is essential, according to Dr. Rodney.

Treatment depends on severity. "There is a risk that the nail could hook on something and rip off, leading to pain and bleeding," Dr. Rodney says. A dermatologist may trim the nail or surgically remove the detached portion to prevent injury.

Other options exist. Dr. Goldenberg cites supplemental biotin and Genadur, a prescription topical nail strengthener. Farah Moustafa, MD, dermatologist and director of Laser and Cosmetics at Tufts Medical Center in Boston, notes that some doctors apply minoxidil — the active ingredient in Rogaine — to the nail, or prescribe it orally.

While research continues, doctors agree nutrition is the front line. Adequate protein plus supplements as directed by the prescriber can support nail health, Dr. Ali says. Dr. Moustafa recommends a varied diet: "Biotin, vitamin B12, vitamins A, C, and E, and minerals such as iron and zinc can play a role for hair and also nail formation." Eggs, salmon, sunflower seeds, and almonds are good sources.

Dr. Ali advises regular follow-ups while on a GLP-1 and logging any new side effects. "If necessary, they will order blood work and check other parameters to lower the risk of future side effects," he says.

With GLP-1 use now mainstream, the findings give dermatologists and prescribers a concrete reason to add nail screening — and protein intake — to the standard checklist of patient monitoring.