Efficacy and safety of minoxidil therapy: A systematic review and meta-analysis weighing the benefits against the risk of hypertrichosis

Background: Hypertrichosis, or excessive hair growth, is a known side effect of minoxidil therapy for androgenetic alopecia. Despite its prevalence, many patients continue treatment due to its effectiveness in hair regrowth. Objective: This study aimed to quantify the prevalence of hypertrichosis associated with oral and topical minoxidil use and evaluate patient adherence despite this side effect. Methods: A systematic review and meta-analysis were conducted, including 27 studies with 4294 participants. Eligible studies assessed hypertrichosis in patients using low-dose oral (≤5 mg/day) or topical minoxidil for alopecia. Results: Hypertrichosis was observed in 23% of patients (95% CI: 0.14–0.32, I² = 98%), with higher rates (10% to 33%) in oral minoxidil across 0.25 mg, 1 mg, and 1.25 mg doses versus topical minoxidil (0% to 2%) across 2% and 5% formulations. Only 0.49% of patients discontinued therapy due to hypertrichosis. Conclusion: Hypertrichosis is a common side effect of minoxidil therapy, and while often mild, it can be distressing for some patients. Clinicians should reassure patients that the benefits of minoxidil therapy for alopecia outweigh the potential for excessive hair growth.