HEALTH
GLP-1 Drugs
Popular weight loss drugs tied to hair loss in study
Anthony ThompsonUSA TODAY
Updated July 23, 2026, 1:55 p.m. ET
People taking popular GLP-1 medications such as Ozempic, Wegovy and Mounjaro may face a higher risk of hair loss than patients using other diabetes drugs, according to a new study published in The British Medical Journal
Researchers from the University of Pennsylvania found that adults with Type 2 diabetes who started GLP-1 drugs had a significantly higher risk of developing alopecia, particularly non-scarring hair loss, compared with people taking two other common classes of diabetes medications. The findings add to growing reports from patients and regulators that have raised questions about whether the medications could contribute to hair loss
The researchers stressed that the overall risk remains low and that the study does not prove that the drugs directly cause hair loss. However, they said the findings provide stronger evidence for what had previously been anecdotal reports and could help patients and doctors make more informed treatment decisions
The study comes as GLP-1 drugs continue to surge in popularity for treating Type 2 diabetes and obesity, with millions of Americans using medications such as semaglutide, sold as Ozempic and Wegovy, and tirzepatide, marketed as Mounjaro
What did the study find?
Researchers analyzed electronic health records from more than 50,000 adults with Type 2 diabetes, comparing people who started GLP-1 drugs with patients taking two other classes of diabetes medications
After accounting for differences such as age and body weight, GLP-1 users had a:
- 37% higher risk of alopecia than patients taking SGLT-2 inhibitors
- 68% higher risk of alopecia than those taking DPP-4 inhibitors
The increased risk was primarily linked to non-scarring alopecia, meaning the hair follicles remain intact and hair may regrow over time. Researchers concluded that while the absolute risk was small, clinicians should be aware of the potential side effect
Why might GLP-1 drugs contribute to hair loss?
The researchers said the most likely explanation is not necessarily the medications themselves, but the rapid weight loss and reduced calorie intake they often produce
Significant calorie restriction can trigger physiological stress and nutritional deficiencies, including low iron, zinc and biotin levels, which can disrupt the normal hair growth cycle and lead to temporary hair shedding
The team also said hormonal and metabolic changes associated with GLP-1 medications could play a role. For example, the drugs have been linked to changes in thyroid function, and their effects on slowing stomach emptying could alter absorption of medications such as thyroid hormone replacement, potentially influencing hair growth. Researchers said additional studies are needed to better understand the underlying mechanisms
Regulators are already reviewing reports
The study notes that reports of hair loss linked to GLP-1 drugs have already been submitted to regulatory agencies in both the United States and the United Kingdom
The U.S. Food and Drug Administration is reviewing reports of hair loss from people taking semaglutide and tirzepatide to determine whether the medications could be linked to the side effect. In the United Kingdom, the Medicines and Healthcare Products Regulatory Agency has received hundreds of reports involving both medications in recent years, including nearly 400 reports tied to tirzepatide so far in 2026
What researchers say patients should know
The authors emphasized that hair loss typically does not cause physical harm, but it can affect self-esteem, quality of life and whether patients continue taking the medications
Because the study was observational, it cannot establish a direct cause-and-effect relationship. Still, the researchers said their findings strengthen earlier safety signals and suggest clinicians should discuss the possibility of hair loss with patients starting GLP-1 therapy, particularly during the first year of treatment, while balancing the drugs’ well-documented benefits for diabetes and obesity
Reporter Anthony Thompson can be reached at ajthompson@usatodayco.com, or on X @athompsonUSAT
