People taking GLP-1 medications for obesity or diabetes may face a greater chance of experiencing hair loss than those using other diabetes treatments, according to new research — though the overall risk remains relatively low.
A team of researchers at the University of Pennsylvania published findings Wednesday in The BMJ showing that patients who had been on GLP-1 drugs for two or more years were 37% more likely to receive a new alopecia diagnosis compared to users of SGLT-2 medications, and 68% more likely compared to those taking DPP-4 drugs.
Despite those elevated odds, the actual occurrence of hair loss was still uncommon — affecting roughly 3 to 9 people out of every 1,000 per year. Each drug category group in the study included between 11,000 and 15,000 participants.
The GLP-1 drugs examined in the study included semaglutide, which is marketed by Novo Nordisk under the brand names Wegovy and Ozempic, as well as tirzepatide, sold by Eli Lilly as Zepbound and Mounjaro, along with older medications in the same drug class.
The SGLT-2 drugs in the comparison included Johnson & Johnson’s Invokana, AstraZeneca’s Farxiga, and Jardiance, made by Boehringer Ingelheim and Eli Lilly. DPP-4 inhibitors in the study included Merck’s Januvia and AstraZeneca’s Onglyza.
A second study, published in the Journal of the American Academy of Dermatology and drawing on data from more than one million participants around the world, found that GLP-1 drug users had significantly higher rates of multiple types of alopecia when compared to those taking metformin, a widely prescribed diabetes medication.
A third study adds another layer to the picture, suggesting that among GLP-1 users, those taking tirzepatide may be at greater risk for hair loss than those taking semaglutide.
Researchers at nference, an analytics firm based in Cambridge, Massachusetts, compared more than 11,000 patients on tirzepatide to the same number on semaglutide. They found that new cases of alopecia occurred in 4.24% of tirzepatide users versus 3.33% of semaglutide users. Among women specifically, the gap was even wider — 5.44% for tirzepatide compared to 3.63% for semaglutide.
All three studies acknowledge that hair loss frequently accompanies significant weight loss and is often temporary. However, the nference research found that tirzepatide users faced higher alopecia rates regardless of how much weight they lost or what dose they received — a finding that raises questions about other possible causes.
The study found that patients with thyroid conditions or other hormonal disorders were more prone to hair loss, pointing to possible connections involving underlying autoimmune, hormonal, or skin-related risk factors.
Venky Soundararajan, who led the nference research, said the findings call for a more tailored approach to patient care. “This supports more individualized counseling and surveillance rather than a generic message that weight loss itself inevitably causes hair loss,” he said.
