Certain GLP-1 therapies, especially semaglutide and tirzepatide, were linked to reported hair loss signals.
Evidence
This PRISMA systematic review included 24 primary studies from 133 records and drew on pharmacovigilance studies and clinical cohorts describing alopecia subtypes, dose patterns, sex differences, and weight-loss links.
Caveat
The evidence remains largely signal-based and observational, so causality, timing, and vulnerable populations were not established by large prospective randomized trials.
Simplified
ObjectiveTo evaluate glucagon-like peptide-1 receptor agonist (GLP-1 RA)-specific associations with hair loss, characterize reported alopecia subtypes and discuss potential underlying mechanisms.MethodsA systematic literature search was conducted across four databases (PubMed, Embase, Scopus, and Web of Science) according to PRISMA guidelines and registered in PROSPERO (CRD420261297384). Studies were included if they were primary articles assessing hair loss related to GLP-1 RA use.ResultsOf 133 studies identified, 24 met inclusion criteria. Among GLP-1 RAs, semaglutide and tirzepatide demonstrated the highest incidence rates of hair loss and more frequent signal detection in pharmacovigilance studies. Although infrequently classified overall, and were the predominant subtypes of hair loss reported. Tirzepatide, associated with the greatest magnitude of weight loss, was most frequently linked to telogen effluvium. Hair loss associated with semaglutide appeared to be dose-dependent, with doses < 2mg weekly rarely implicated while higher obesity-treatment doses were more commonly associated with hair loss. Females appeared to be disproportionately affected. Rapid weight loss emerged as a potential contributor, particularly for telogen effluvium. In contrast, fewer studies assessed hair loss with liraglutide, dulaglutide, lixisenatide and exenatide, and they typically exhibited lower reported risk when compared to semaglutide and tirzepatide.ConclusionsAccumulating evidence from pharmacovigilance databases and clinical cohorts suggests an increased risk of hair loss with certain GLP-1 RAs, particularly semaglutide and tirzepatide. Further studies are needed to clarify the etiology of drug-induced weight loss, identify vulnerable populations, and establish causality and temporal relationship through large, prospective randomized trials.
Key numbers
6.0 per 1000 patient-years
Alopecia Incidence Rate
Alopecia incidence for GLP-1 RA users vs. placebo groups.
7%
Alopecia Risk with Semaglutide
Reported alopecia in patients on high-dose oral semaglutide.
5.4%
Alopecia Risk with Tirzepatide
Alopecia incidence in participants treated with tirzepatide vs. placebo.
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Declaration of conflicting interestThe authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Authors AKG, EMT and VE declared no potential conflicts of interest with respect to research, authorship, and/or publication of this article. PM reports research grants for conducting clinical trials from Amgen, Sun Pharmaceuticals, Eli Lilly, Incyte, and Pfizer; has served on the board of directors and medical advisory board for the American Hair Research Society, National Alopecia Areata Foundation, and Scarring Alopecia Foundation; and is a consultant for NeoGenesis.
GLP-1 Therapies