Treatment of androgenetic alopecia in transgender people receiving testosterone therapy with sublingual minoxidil: A randomized, double-blind, placebo-controlled clinical trial.

Abstract

Transgender people receiving testosterone may experience androgenetic alopecia. Treatments such as 5α-reductase inhibitors can interfere with masculinization. To assess the efficacy and safety of sublingual minoxidil in the treatment of mild androgenetic alopecia in transgender people receiving full-dose testosterone therapy. Participants were randomized 1:1 to receive either sublingual minoxidil 1.35 mg twice daily or placebo for 24 weeks; all received sublingual minoxidil 2.5 mg twice daily in an open-label extension phase. Tattoo-directed phototrichograms were performed. Co-primary endpoints were change in midfrontal and vertex target area hair count. Forty-six participants were randomized (23 per arm). At Week 24, midfrontal target area hair count improved by +15.7 hairs/cm² with minoxidil vs placebo (P = .03) but no difference observed in the vertex. In the exploratory open-label phase, net midfrontal improvement from Week 0 to 48 was +12.3 hairs/cm² (P = .02) and significant gains in the vertex occurred by Week 48 compared to baseline (+37.9 hairs/cm², P = .009). Minoxidil was well tolerated, with no effect on testosterone concentrations or serious adverse events. Mild baseline androgenetic alopecia may have reduced detection of change in global photographs and quality-of-life scores. Sublingual minoxidil was an effective and well tolerated option in this population for promoting hair growth in trans people receiving testosterone.