CLINICAL QUESTION

Is low-dose oral minoxidil as effective as topical minoxidil for the treatment of androgenetic alopecia?

BOTTOM LINE

This small study suggests that oral minoxidil, 5 mg, once daily is roughly equivalent to topical minoxidil once daily for men with androgenetic alopecia. A 2-month supply (30 10-mg tablets) costs $20 for the oral version compared with approximately $20 to $30 per month for the topical version (as of August 28, 2024, on GoodRx.com). (Level of Evidence = 1b−)

SYNOPSIS

Although topical minoxidil has been approved by the US Food and Drug Administration for the treatment of androgenetic alopecia for years, some observational studies have proposed a benefit from low-dose oral minoxidil. The researchers at a dermatology clinic in Brazil identified 90 men, 18 to 55 years of age, with androgenetic alopecia. Patients with a history of hair transplant or other treatment for alopecia in the previous 6 months were excluded. At baseline, the men's average age was 37 years, and they had significant hair recession, many with involvement of the vertex; according to the Norwood-Hamilton scale, they were grades 3V to 5V. Groups seemed to be balanced, and analysis was by intention to treat. Patients were randomized to receive oral minoxidil, 5 mg, once daily plus placebo solution twice daily, or oral placebo plus topical minoxidil 5% twice daily. They were followed up for 24 weeks, and the primary outcome was terminal hair density in the affected or target area. At 24 weeks, improvements from baseline were similar for all outcomes, with the only statistically significant difference being better terminal hair density on the vertex with the oral minoxidil. The other difference was in adverse events, with more hypertrichosis (49% vs 25%) and headache (14% vs 2%) with the oral version and more scalp eczema (16% vs 2%) with the topical version. A limitation of the study was a high rate of loss to follow-up due to the COVID-19 pandemic, with only 68 of the original 90 men completing the study.