Exploring the hair loss risk in glucagon‐like peptide‐1 agonists: Emerging concerns and clinical implications

Abstract

Emerging evidence suggests a potential association between glucagon-like peptide-1 (GLP-1) receptor agonists and alopecia. Drug-induced hair loss is a recognized adverse effect linked to various medications, including chemotherapeutics, immunosuppressants and certain biologics.1 Recently, semaglutide and tirzepatide—two GLP-1 receptor agonists widely used in managing type 2 diabetes mellitus and obesity—have been implicated in hair loss. A study by Godfrey et al.2 conducted a disproportionality analysis using data from the FDA Adverse Event Reporting System (FAERS) between 2022 and 2023. The authors identified elevated reporting odds ratios (RORs) for alopecia associated with semaglutide (ROR: 2.46; 95% CI: 2.14–2.83) and tirzepatide (ROR: 1.73; 95% CI: 1.42–2.09). These findings suggest a potential link between these medications and hair loss, an adverse event not previously reported in clinical trials.2, 3 Interestingly, this association was observed with the once-weekly GLP-1 agonists semaglutide and tirzepatide but not with the older, once-daily injectable liraglutide. The mechanisms underlying this association remain speculative. Previous studies have demonstrated the expression of GLP-1 receptors in murine hair follicles, although their precise role within the hair growth cycle is not clearly defined.4 This raises the possibility that GLP-1 agonists could influence hair growth cycles. However, human data are lacking, necessitating further research. Alternatively, the rapid weight loss induced by these agents may precipitate telogen effluvium (TE), a form of non-scarring alopecia characterized by diffuse hair shedding often seen following metabolic stress.1 TE is well documented in patients experiencing significant weight loss, such as after metabolic and bariatric surgery.5 The metabolic changes and nutritional deficiencies associated with rapid weight reduction may disrupt the hair growth cycle, leading to increased shedding. Clinically, this potential adverse effect warrants attention. Patients initiating GLP-1 agonists like semaglutide or tirzepatide should be informed about the possibility of hair loss, especially those with a history of alopecia or concerns about hair appearance. Monitoring for signs of TE and providing nutritional support may mitigate this risk. Since TE is generally reversible, reassurance and patient education are essential. Clinicians are advised to include GLP-1 agonists in the medication history of patients presenting with hair loss, discuss the possibility of hair shedding when initiating these therapies and ensure patients maintain adequate nutrition to mitigate the risk of TE. Further investigations are needed to elucidate the relationship between GLP-1 agonists and alopecia. Prospective studies assessing hair loss incidence in patients undergoing treatment with these agents, controlling for weight loss and nutritional status, would provide more definitive evidence. Exploring the expression and role of GLP-1 receptors in human hair follicles could also shed light on potential direct effects. Such studies could help identify risk factors that predispose certain individuals to alopecia with these medications or guide clinical dose adjustments. In conclusion, the study by Godfrey et al.2 highlights a possible association between GLP-1 agonists and alopecia, underscoring the importance of pharmacovigilance in detecting rare adverse events. Clinicians should remain vigilant, discuss potential side effects with patients and consider monitoring hair health during treatment with semaglutide and tirzepatide. Ongoing research is essential to confirm these findings and guide clinical practice. None. Michael G. Buontempo has no conflicts to disclose. Bianca T. Santos has no conflicts to disclose. Data sharing not applicable to this article as no datasets were generated or analysed during the current study.

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