GLP-1 medications are linked to hair loss in Type 2 diabetes

Patients with Type 2 diabetes who are taking GLP-1 medications are more likely to lose their hair than those treated with other diabetes medications, according to a new analysis conducted by researchers at the University of Pennsylvania and published recently in The BMJ.

“Hair loss has been reported anecdotally, but clinical trials to this point were not designed to evaluate this outcome. Given the widening use of these medications, we felt it was important to systematically examine this potential side effect in real-world patients,” senior author Yong Chen, Ph.D., a professor of Biostatistics and Informatics at the University of Pennsylvania Perelman School of Medicine, said in a news release.

Chen and his colleagues wanted to understand the impact of GLP-1 therapies, such as Ozempic (semaglutide) and Mounjaro (tirzepatide), on hair loss. They assessed electronic health record data from adults with Type 2 diabetes seen at the University of Pennsylvania Health System between January 2019 and September 2024. They focused on patients who were starting new medications. Researchers excluded those with Type 1 diabetes and those who already had a diagnosis of alopecia or a diagnosis of end-stage renal disease

They compared adult patients taking GLP-1 therapies with those taking SGLT2i medications, such as Jardiance (empagliflozin), and DPP4i medications, such as Januvia (sitagliptin). They made two comparisons. First they compared 12,004 people who started taking GLP-1 therapies with 15,221 who started taking an SGLT-2 inhibitor. The second comparison assessed 11,964 people who started a GLP-1 therapy compared with 11,238 patients who started a DPP-4 inhibitor.

Researchers found that users of GLP-1s were 37% more likely to report hair loss than patients using SGLT2i. Compared with users of DPP4i, patients taking GLP-1s were 68% more likely to have hair loss. The findings were consistent across age and sex.

Researchers suggested in their paper that rapid or substantial weight loss can trigger a temporary non-scarring hair shedding. This type of hair loss can happen after people experience stress or change in the body.

“Hair loss may reflect downstream effects of metabolic change rather than a direct drug effect,” researchers wrote. “Other contributing factors may include the broad metabolic, hormonal, and immunological effects attributed to GLP-1 receptor agonists that may influence hair follicle growth and cycling.”

Researchers suggested further study to clarify why the hair loss happens. They also suggest future studies collect patient-reported outcomes and more detailed clinical assessments may help to better characterize the frequency and severity of alopecia.

Limitations include the possibility of confounding, and researchers said efforts to mitigate bias may not have fully accounted for factors such as disease severity, lifestyle characteristics or family history of alopecia. Secondly, alopecia is identified by using diagnostic codes in the medical record and may not be identified by everyone with alopecia. Additionally, the medications that patients were prescribed were also identified through claims data, but that may not have captured actual use.