Popular weight-loss medications such as Ozempic, Wegovy, Mounjaro and Zepbound may be associated with unexpected changes in nail and hair health, according to research presented at the European Academy of Dermatology and Venereology Congress in Vienna in October 2026.

The findings suggest that people taking GLP-1 medications report nail detachment, discolouration and hair loss more frequently than those who have never used these treatments. However, researchers emphasise that the results do not prove the medications directly cause these problems.

What Did The Researchers Discover?

The study examined 1,904 adults from France, the United States, Brazil and Mexico. Among them, 575 were taking GLP-1 medications, while 1,329 had obesity, type 2 diabetes or both conditions but had never used these drugs. Participants had received treatment for an average of 18.5 months.

Researchers found that 39% of medication users reported nail detachment, compared with 9% of nonusers. Nail discolouration was also more common, affecting 46% of users versus 17% of those without treatment.

Brittle nails and unusual ridges were reported more frequently among people receiving GLP-1 medications.

Why Can Fingernails Become Detached?

Nail detachment, medically known as onycholysis, occurs when the nail separates from the underlying nail bed. The affected area may appear white or change colour. Although the initial findings suggested a strong association, the relationship became much weaker when researchers considered only problems that developed after treatment began.

Study author Dr Charles Taïeb explained that many participants already had nail abnormalities before starting medication. He suggested that underlying health conditions could account for much of the difference between the groups.

The findings have been submitted for peer review and require further investigation.

What About Hair Loss?

A companion study involving the same participants examined hair and scalp symptoms. Unusual hair loss affected 50% of GLP-1 users, compared with 34% of nonusers. Reduced hair volume was reported by 42% and 19%, respectively. Hair loss beginning after treatment started was reported by 26% of users, compared with 12% of nonusers.

Scalp redness was approximately three times as common among medication users. Researchers suggested that inflammation might contribute to hair changes in some patients.

Could Nutrition Explain These Changes?

Dermatologist Dr Tanya Evans explained that reduced appetite may lead some patients to consume insufficient protein, iron or zinc, all essential for healthy hair and nail growth.

Rapid weight loss can also temporarily disrupt the normal hair growth cycle. Bariatric surgeon Dr Mir Ali noted that similar changes occur in patients who lose substantial weight following surgery. He explained that hair growth often improves once weight and metabolic conditions stabilise.

However, nutritional deficiencies and weight loss may not explain every reported symptom.

How Can Patients Protect Their Hair And Nails?

Experts recommend maintaining adequate nutrition throughout treatment, particularly sufficient protein and essential vitamins and minerals.

Patients who notice persistent nail discolouration, detachment or unusual hair shedding should consult a healthcare professional. A dermatologist can investigate possible causes, including infections, injuries, inflammatory conditions and nutritional deficiencies. Dr Evans advised against stopping GLP-1 treatment solely because nail changes appear. Instead, she recommended discussing symptoms with the prescribing clinician.

Damaged fingernails typically require four to six months to regrow, while toenails may take nine to twelve months.

What Do The Findings Mean?

The research highlights potential dermatological concerns associated with GLP-1 treatment, but its observational design cannot establish cause and effect. Because symptoms were self-reported and many existed before treatment, further controlled studies are needed.

For patients, the key message is to monitor changes, maintain balanced nutrition and seek medical advice when symptoms persist.