GLP-1 Drugs Linked to Hair Loss and Nail Changes in New Studies

People taking popular weight-loss and diabetes drugs may be more likely to report hair loss and nail problems, according to two studies released this week. The findings, published in research presented on October 2 and in a study published in the Journal of Investigative Dermatology, point to possible links but do not prove that GLP-1 medications such as Ozempic, Wegovy and Zepbound cause these problems.

The research adds to growing questions about changes some patients notice after starting GLP-1 treatment. But the studies examined different things: one compared reported symptoms among medication users and non-users, while the other looked at genetic clues linked to male-pattern hair loss. Neither establishes that the drugs directly cause hair or nail damage.

What researchers found about hair and nails

One research team, made up of scientists in France and Italy, compared 575 people taking a GLP-1 medication with 1,379 people who had type 2 diabetes or obesity but had not started the treatment. The researchers conducted separate studies on hair and nail problems. Participants had used the medication for an average of 18.5 months, and the studies tracked weight changes over three months.

About half of the GLP-1 users reported unusual hair loss, compared with roughly one-third of those who were not taking the drugs. Users were also more likely to report scalp irritation. The researchers found that scalp problems were not linked to how much weight a person had lost, suggesting that weight loss alone may not explain every reported symptom.

The difference in nail problems was also notable. Around 66% of GLP-1 users reported nail issues, compared with 53% of non-users. Nail detachment was reported by about 39% of users and 9% of non-users. Discoloration was reported by 46% of users, compared with 17% of the control group.

The studies were presented at the European Academy of Dermatology and Venereology conference. They have not yet gone through formal peer review. The researchers also said the results show an association, not proof of cause and effect.

A separate study points to a possible biological link

A study by researchers at NYU Langone Health, published in the Journal of Investigative Dermatology, examined whether higher activity of the GLP-1 receptor was linked to male-pattern hair loss.

The researchers studied genetic variations associated with naturally higher levels of GLP-1 receptors. They then checked whether those variations were linked to male-pattern hair loss, which can cause a receding hairline, thinning at the temples, and a bald spot on the crown.

They found that higher GLP-1 activity was associated with about 7% greater odds of male-pattern hair loss. However, none of the people in this study were taking GLP-1 medication. The finding therefore does not show that the drugs increase hair loss among users.

“Genetic association does not equal drug effect,” Justin Ko, chief of dermatology at Stanford Health Care, told The Washington Post. Ko, who was not involved in the research, said the finding was suggestive but did not establish a cause.

The study also included mostly men of European ancestry, so it remains unclear whether the results apply to women or other populations.

Weight loss may also explain hair shedding

Doctors say hair loss among people taking GLP-1 drugs can have several possible explanations. Rapid weight loss, changes in metabolism, and not getting enough nutrients may all contribute.

One known cause is telogen effluvium. This happens when physical stress causes more hair follicles than usual to enter a resting phase, leading to increased shedding. It can occur after rapid weight loss, surgery, or crash dieting.

Carolyn Goh, a clinical professor of dermatology at UCLA Health, told The Washington Post: “It could be the medication, it could be the weight loss, it could be metabolic changes, it could be insufficient nutrition. There are a lot of different things that could be going on.”

Hair shedding from this condition may begin two to three months after the triggering event, making it difficult to identify the cause. It is often temporary, and hair may regrow over six to 12 months, Ko said.

The nail study also found that existing health problems, skin conditions and nutritional deficiencies could help explain some nail changes.

What GLP-1 users should do

Researchers say patients should tell their doctors about ongoing hair shedding, scalp irritation or nail changes rather than assuming the medication is responsible. People taking GLP-1 drugs should also discuss whether they are getting enough protein and other nutrients, and whether their weight is dropping too quickly.

Charles Taïeb, a clinical dermatologist at Necker University Hospital in Paris and an author of the hair and nail studies, advised patients not to stop treatment on their own. Speaking to Gizmodo, he said: “Do not panic, and do not stop an effective treatment on your own because of your hair or nails, but do mention these symptoms to your doctor.”

The research teams say further studies are needed, including studies that follow patients from the start of treatment and use medical examinations to track changes. For now, the findings raise questions for researchers and clinicians, but they do not show that hair loss or nail damage is an expected result of taking GLP-1 medication.