A peer‑reviewed BMJ study of nearly 50,000 adults with type‑2 diabetes compared users of GLP‑1 receptor agonists (semaglutide – sold as Ozempic, Wegovy – and tirzepatide – sold as Mounjaro) with patients taking other diabetes drugs (SGLT‑2 and DPP‑4 inhibitors). After adjusting for age, sex, ethnicity, BMI and comorbidities, GLP‑1 users had a 37 % higher incidence of clinically recorded alopecia compared with SGLT‑2 inhibitors and a 68 % higher incidence compared with DPP‑4 inhibitors. The absolute rates remained low, ranging from roughly 3 to 9 cases per 1,000 person‑years.
Regulatory agencies in the United States and United Kingdom have opened safety evaluations. The FDA confirmed it is reviewing the signal, and the UK Medicines and Healthcare products Regulatory Agency (MHRA) recorded 399 new tirzepatide‑related hair‑loss reports in 2026, up from 541 the previous year, alongside 148 semaglutide reports. Researchers note the association may reflect rapid weight loss, nutritional deficiencies (iron, zinc, biotin) or physiological stress rather than a direct drug effect, but the finding could influence patient counseling, adherence, and monitoring practices.