Efficacy and Safety of Oral Minoxidil 5 mg Once Daily in the Treatment of Male Patients with Androgenetic Alopecia: An Open-Label and Global Photographic Assessment

Introduction: Oral minoxidil is an antihypertensive vasodilator known to stimulate hair growth. The use of low-dose oral minoxidil for the treatment of male androgenetic alopecia (AGA) is receiving increasing attention. The aim of this study was to evaluate the efficacy and safety of oral minoxidil for the treatment of male AGA.

Methods: This was an open-label, prospective, single-arm study. Thirty men aged 24-59 years with AGA types III vertex to V were treated with oral minoxidil 5 mg once daily for 24 weeks. Efficacy was evaluated by hair counts, hair diameter measurements, photographic assessment, and self-administered questionnaire. The safety of the treatment was closely monitored by means of physical examinations and laboratory investigations.

Results: There was a significant increase in total hair counts from baseline at weeks 12 (mean change + 26, range 182.5-208.5 hairs/cm²) and 24 (mean change + 35.1, range 182.5-217.6 hairs/cm²) (both p = 0.007). Photographic assessment of the vertex area by an expert panel revealed 100% improvement (score > + 1), with 43% of patients showing excellent improvement (score + 3, 71-100% increase). The frontal area also showed a significant response but less than that of the vertex area. Common side effects were hypertrichosis (93% of patients) and pedal edema (10%). No serious cardiovascular adverse events and abnormal laboratory findings were observed.

Conclusion: Oral minoxidil 5 mg once daily effectively increased hair growth in our male patients with AGA and had a good safety profile in healthy subjects. However, oral minoxidil should be used carefully with men who have severe hypertension and increased risk for cardiovascular events.

Keywords: Androgenetic alopecia; Asian; Male pattern hair loss; Oral minoxidil; Side effects; Treatment.