New research involving approximately 50,000 patients suggests a potential link between popular weight loss and diabetes drugs, such as Ozempic, Wegovy, and Mounjaro, and an increased risk of hair loss. The study, published in The British Medical Journal (BMJ), found that individuals using GLP-1 receptor agonists were more likely to experience alopecia compared to those on other diabetes medications.
Experts analyzed electronic patient data from the University of Pennsylvania Health System. In the study, users of GLP-1 drugs were compared with users of SGLT-2 inhibitors and DPP-4 inhibitors, two other classes of diabetes medications. After adjusting for factors like age and weight, researchers observed that GLP-1 users had a 37% higher risk of alopecia than those taking SGLT-2 inhibitors. The risk was even higher when compared to users of DPP-4 inhibitors, with GLP-1 users showing a 68% increased risk of hair loss.
The findings indicated that the hair loss associated with these drugs is likely non-scarring alopecia, a condition where hair follicles remain intact, suggesting the potential for hair regrowth. Regulators in the United States have been informed of these reports, particularly concerning semaglutide (the active ingredient in Wegovy and Ozempic) and tirzepatide (the active ingredient in Mounjaro). The U.S. Food and Drug Administration (FDA) has stated it is evaluating this potential safety signal.
In the UK, regulatory agencies have also received numerous reports. The Medicines and Healthcare products Regulatory Agency (MHRA) reported 399 hair loss cases related to tirzepatide in 2026, in addition to 541 reports the previous year. For semaglutide, the MHRA received 148 reports in 2026 and 164 in the prior year.
While the exact mechanisms are still under investigation, researchers propose that rapid weight loss and reduced caloric intake associated with these drugs may trigger physiological stress and micronutrient deficiencies, disrupting the hair growth cycle. Other potential factors include the metabolic, hormonal, and immunological effects of GLP-1 receptor agonists, which could influence hair follicle function, possibly through endocrine pathways, especially in individuals with pre-existing hormonal conditions.
GLP-1 receptor agonists mimic hormones that regulate appetite and have been shown to aid significant weight loss and manage chronic diseases. Despite the observed association with hair loss, experts emphasize that the benefits of these drugs for glycemic control, weight reduction, and mitigating obesity-related complications are substantial. Dr. Marie Spreckley, a weight management researcher at the University of Cambridge, noted that the absolute risk of hair loss remains relatively low and that for many patients, the established benefits likely outweigh this potential side effect.