Glucagon-like peptide-1 receptor agonists and hair loss: A systematic review and meta-analysis.

This systematic review and meta-analysis investigated whether glucagon-like peptide-1 receptor agonist (GLP-1 RA) use is associated with hair loss. Researchers searched four electronic databases through August 2025, identifying nine interventional studies (seven RCTs and two prospective non-randomized trials) involving 4,114 GLP-1 RA users. Using a random-effects model, the pooled analysis found that GLP-1 RA users had a significantly higher risk of hair loss compared to placebo users (risk ratio: 3.252; 95% CI: 1.437–7.358). This association remained significant in a subgroup analysis restricted to RCTs enrolling patients with overweight or obesity (RR: 3.587; 95% CI: 2.100–6.124). A single-arm analysis estimated the overall event rate of hair loss at approximately 3.9%. Limitations of this study include the relatively small number of included studies (n=9), potential variability in how hair loss was defined and reported across trials, and the inability to fully disentangle hair loss attributable to the drug itself versus rapid weight loss—a known independent trigger of telogen effluvium. The authors conclude that GLP-1 RA use is significantly associated with an increased risk of hair loss.

Why this grade: The meta-analysis pools data from predominantly RCTs in humans, but the small number of included studies (n=9), heterogeneity in hair loss reporting, and inability to separate drug-specific from weight-loss-induced effects limit the overall strength of evidence.