Prevalence and Predictors of Hair Shedding among GLP-1 Receptor Agonist Users: A Cross-Sectional Study from Saudi Arabia.

INTRODUCTION: Although glucagon-like peptide-1 receptor agonists (GLP-1 RAs) demonstrate remarkable efficacy for weight management, emerging pharmacovigilance data suggest an increased hair loss risk, particularly with newer agents. This study investigated the prevalence, risk factors, and clinical impact of hair shedding in GLP-1 RA users in Saudi Arabia. METHODS: A cross-sectional survey was conducted between September 2024 and January 2025 of current and former GLP-1 RA users. Participants with preexisting hair loss were excluded from the study. Hair shedding prevalence, associated factors, and the impact on treatment discontinuation were assessed using validated questionnaires. Multivariate logistic regression was used to identify independent predictors. RESULTS: Among 152 eligible participants (87.5% female, median body mass index 32.1 kg/m), 70.4% ( = 107) reported hair shedding after GLP-1 RA initiation, which was markedly higher than the 3-7% reported in clinical trials. Tirzepatide users had the highest prevalence (76.7%), followed by semaglutide (64%) and liraglutide (54.5%). Hair shedding was significantly associated with female sex (92.5% vs. 75.6% in males, = 0.009), greater magnitude of weight loss (82.7% prevalence with ≥15% weight loss vs. 40% with <5%, = 0.002), and medication discontinuation (63.6% vs. 40% in non-shedders, = 0.013). Multivariable analysis confirmed independent associations with increasing weight loss (OR 1.79, 95% CI: 1.19-2.76, = 0.006) and female sex (OR 3.57, 95% CI: 1.20-11.11, = 0.023). Critically, 39.7% of the affected patients cited hair shedding as their reason for discontinuation, although 37.7% reported resolution after stopping treatment. The median weight loss was 15.9% [IQR 8.69-22.5], with 53.3% achieving ≥15% reduction. CONCLUSION: Hair shedding affects seven out of ten GLP-1 RA users in real-world settings, representing a ten-fold higher prevalence than that reported in registration trials. This under-recognized phenomenon during GLP-1 RA therapy significantly affects treatment adherence, particularly among women who achieve substantial weight loss. Proactive counseling and nutritional optimization strategies are essential to maintain treatment persistence.