Adults taking glucagon-like peptide-1 receptor agonists (GLP- 1 RAs) had significantly higher odds of nonscarring hair loss compared with matched controls at both 6 and 12 months, according to a real-world multicenter cohort study published in JAAD International.
Researchers used the TriNetX US Collaborative Network, a de-identified electronic health record platform drawing from 67 US health care organizations, to evaluate hair loss incidence and risk in adults aged 18 to 89 years and adolescents aged 12 to 17 years treated with GLP- 1 RAs from 2014 to 2024. Patients with at least 2 prescriptions for a GLP- 1 RA were compared with controls who had at least 2 general medical encounters and no exposure to these medications. Patients with confounding dermatologic, endocrine, nutritional, or systemic conditions were excluded. After propensity score matching on age, sex, race, body mass index, and type 2 diabetes status, each matched adult cohort included 547,993 patients.
Nonscarring hair loss subtypes — telogen effluvium (TE), androgenetic alopecia (AGA), and alopecia areata (AA) — were identified using International Classification of Diseases, Tenth Revision codes. Logistic regression was used to estimate adjusted odds ratios at 6- and 12-month follow-up intervals.
At 6 months, GLP- 1 RA use was associated with 1.62 times the odds of AGA and 1.26 times the odds of overall nonscarring hair loss vs controls. The association with TE at 6 months did not reach statistical significance. By 12 months, all three primary endpoints were significant: TE showed 1.76 times the odds, AGA 1.64 times the odds, and overall nonscarring hair loss 1.40 times the odds among patients receiving GLP- 1 RAs. AA was not significantly associated with use at either time point and was more common among controls, suggesting these medications do not meaningfully affect autoimmune hair loss.
Temporal trend analysis showed that overall nonscarring hair loss incidence in both groups rose between 2014 and 2024, with the curves beginning to diverge around 2019 and GLP- 1 RA users showing consistently higher rates by 2023 to 2024. Rates of TE and AGA tracked similarly between groups until 2021 to 2022, after which they increased more steeply among medication users.
Researchers proposed several potential mechanisms for the observed associations, including rapid weight loss, alterations in insulin and insulin-like growth factor-1 signaling, androgen changes, and possible direct follicular effects. The findings align with prior pharmacovigilance analyses linking alopecia to semaglutide and tirzepatide.
In the adolescent subgroup, 10 or fewer patients receiving GLP- 1 RAs were identified for each hair loss outcome, precluding meaningful comparative analysis. Researchers noted this finding highlights barriers to access in pediatric populations.
The study carries limitations inherent to its retrospective, database-driven design. The researchers acknowledged the possibility of residual confounding despite propensity score matching and noted that code-based outcome ascertainment may not capture all cases. The small pediatric sample size constrained subgroup conclusions.
“Awareness of alopecia risk in patients on GLP- 1 RAs is critical for early detection, anticipatory guidance, and multidisciplinary care,” the researchers wrote, calling for future research into underlying mechanisms, prospective monitoring strategies, and pediatric outcomes.
The researchers reported no funding sources and no conflicts of interest.
Source: JAAD International