Ozempic linked to nail damage warning

Weight-loss injections may cause some patients to lose fingernails, according to research.

The study found that 60% of people using the high-profile jabs developed problems such as loose nails and discolouration, with nails turning black or yellow.

Researchers also said the chance of nail detachment was four times higher among people taking the medication than among those who were not.

Experts think injections such as Ozempic, Wegovy and Mounjaro may trigger nutrient shortages that lead to a lack of keratin, the protein that forms nails.

The team also looked at effects on the scalp and found that users could experience redness, scaling and itching.

The findings add to earlier studies that have linked the jabs to cosmetic side effects such as gaunt facial features, loose skin around the neck and hair loss.

Speaking at the European Academy of Dermatology and Venereology Congress in Austria, lead author Dr Charles Taïeb said the evidence for effects on skin, hair and nails is “not just anecdotal”.

The research compared 575 people using weight-loss injections with 1,329 patients with type 2 diabetes, obesity or both who had never taken the drugs.

In total, 66% of jab users reported at least one nail disorder, compared with just over half, or 53%, of those who had not taken the drugs.

Alongside nail detachment, where the fingernail or toenail separates from the skin underneath, nail discolouration was also far more common among weight-loss drug users, affecting 46% compared with 17% of others.

Even when compared with patients who lost weight through diet and exercise, the injection group still reported more nail problems.

The researchers suggested the rapid weight loss caused by the drugs may place stress on the body.

Because nails are not essential for survival, the body may divert nutrients and resources to more vital organs and processes, which can disrupt healthy nail growth.

Severe calorie restriction may also lead to micronutrient deficiencies, including iron, zinc and biotin, all of which are important for nail health.

A separate analysis involving the same participants found that hair loss was also common among jab users.

About half of people taking the drugs, known as GLP-1 agonists, reported increased hair shedding, compared with just over a third of non-users.

Hair thinning also affected more than 40% of slimmers, while scalp redness was around three times more common in this group.

Hair loss rarely appeared on its own and was often accompanied by itching and scaling skin, the researchers said.

Dr Bruno Halioua, another author of the study, said: “This suggests that what is happening on the scalp may go beyond the classical shedding seen after rapid weight loss and involve an inflammatory component.”

The dermatologist added that doctors often miss the impact of weight-loss injections on scalp health, even though the problems can be treated with moisturisers and steroid creams.

“These changes are frequent and are not a reason to stop treatment, but anyone who notices hair shedding, an itchy red scalp or nail changes should mention it to their doctor,” he added.

Hair thinning is listed as a common side effect of the drugs, which are taken by up to 2.5 million Britons.

Data published earlier this year by the UK Medicines and Healthcare products Regulatory Agency showed 940 reports of hair loss linked to tirzepatide, the active ingredient in Mounjaro, since the start of 2025.

At least 312 reports have also been filed for Wegovy and Ozempic.

Previous analysis suggests the hair loss is a form of non-scarring alopecia, in which hair follicles remain intact and regrowth is possible.