Topical Versus Oral Minoxidil: Differences in Efficacy for Men with Androgenetic Alopecia

Mariana Alvares Penha, MD, MSc

Credit: Doctoralia

A low dose of oral minoxidil has similar efficacy to topical minoxidil, 5%, in male patients with androgenetic alopecia, according to recent findings, and it may work as an option for those who prefer oral treatment or have issues with topicals.¹

These findings represent the conclusion of recent research from investigators in Brazil who compared both topical and oral minoxidil options for male hair regrowth among patients with androgenetic alopecia. It was led by Mariana Alvares Penha, MD, MSc, from the department of dermatology at the Faculty of Medicine of Botucatu in São Paulo State University (UNESP).

The investigators noted the rise in interest observed worldwide in oral, low-dose minoxidil as a possible alternative option for androgenetic alopecia, adding that while the therapy has already been assessed, there had not been comparative therapeutic trials for this population.²

“This double-blind, placebo-controlled randomized clinical trial aims to compare the efficacy, safety, and tolerability of oral minoxidil, 5 mg, once per day vs topical minoxidil, 5%, twice per day for 24 weeks for male patients with AGA,” Penha and colleagues wrote.

Background and Methods

The investigators used a double-blind, parallel, placebo-controlled, randomized trial design which they carried out at a single center, holding their follow-up meetings with participants over 24 weeks.

Subjects were given randomly assignment in a 1:1 ratio to 2 possible study arms: those given a dose of oral minoxidil at 5 mg per-day along with a placebo solution for topical application twice per-day, and the those given 1 mL of topical minoxidil at 5% twice per-day along with an oral placebo once per-day.

The team recruited 90 male patients in the age range of 18 - 55 years, and they were enrolled at a specialized clinic in Presidente Prudente, Brazil. Recruitment lasted from January - December 2021, and all participants had a diagnosis of androgenetic alopecia by a board-certified dermatologist using clinical and trichoscopic assessment.

The investigators focused specifically on assessing the main impact on subjects’ terminal hair density in the frontal and vertex regions of their scalps. A secondary aim of the research team was to evaluate changes observed in overall hair density as well as photographic evaluations.

The team’s oral minoxidil capsules, placebo scalp solution, topical minoxidil solution, and placebo capsules were all provided by a compounding pharmacy, the process of which ensured identical appearance, packaging, and sensory perception. Their placebo solution was formulated to mimic the active solution as far as its composition and appearance, thereby maintaining consistency across the study arms.

Findings

Overall, among the 90 subjects, 68 were able to finish the trial, and the average age was 36.6 years. As far as the group divisions, 1 arm contained 33 subjects who received oral minoxidil and the other had 35 who received topical therapy, with both arms having been similar in demographic data and reported severity of androgenetic alopecia.

In their assessment of hair density changes at subjects’ frontal area from the point of baseline to the 24-week mark, a mean increase of 3.1 hairs per cm² (95% confidence interval [CI], −18.2 to 21.5; P = .27) was observed by the research team in subjects’ terminal hair density and 2.6 hairs per cm² (95% CI, −10.3 to 15.8; P = .32) was observed in total hair density for both arms.

They also reported that the mean change in the vertex area from baseline to the 24-week mark was 23.4 hairs per cm² (95% CI, −0.3 to 43.0; P = .09) in terms of their terminal density and 5.5 hairs per cm² (95% CI, −12.5 to 23.5; P = .32) in terms of their total hair density.

In their analysis of photographs, the investigators found that oral minoxidil had been more effective than topical minoxidil on participants’ vertex region (24%; 95% CI, 0 to 48; P = .04) but it had not been more effective in the frontal scalp region (12%; 95% CI, −12 to 36; P = .24). Additionally, the team noted that the subjects’ most common side effect reported among those in the oral minoxidil arm had been hypertrichosis for 49% and headache for 14%.

“Nevertheless, the overall photographic improvement in the vertex was superior in the oral minoxidil group,” they wrote. “Low-dose oral minoxidil has shown to be well tolerated and, therefore, is an option for patients who prefer oral therapy or are intolerant to topical treatment.”

References

1. ^{Penha MA, Miot HA, Kasprzak M, Müller Ramos P. Oral Minoxidil vs Topical Minoxidil for Male Androgenetic Alopecia: A Randomized Clinical Trial. JAMA Dermatol. Published online April 10, 2024. doi:10.1001/jamadermatol.2024.0284.}
2. ^{Gupta AK, Venkataraman M, Talukder M, Bamimore MA. Relative efficacy of minoxidil and the 5-α reductase inhibitors in androgenetic alopecia treatment of male patients: a network meta-analysis. JAMA Dermatol. 2022;158(3):266-274. doi:10.1001/jamadermatol.2021.5743.}