Minoxidil vs Conventional Androgenic Alopecia Treatments

The relative efficacy of minoxidil for male androgenic alopecia (AGA) treatment compared with conventional 5-a reductase inhibitor treatments found oral dutasteride to be most effective for AGA, according to a meta-analysis published in JAMA Dermatology.

Investigators conducted systemic literature searches in PubMed on March 5, 2021, without date restrictions. They included studies that investigated monotherapy with any dose and administration route of minoxidil, dutasteride, and finasteride for male AGA. They incorporated single-arm trials into a network of randomized studies, and combined randomized and observational data using naïve pooling. The outcomes of interest were change in total and terminal hair count after 24 and 48 weeks of therapy, quantified in hairs per cm². A network meta-analysis was conducted for each outcome under a Bayesian random-effects model.

A total of 23 studies were included in the analysis. The mean patient age ranged from 22.8 years to 41.8 years.

The greatest increase in total hair count at 24 weeks was seen with 0.5 mg/d of dutasteride treatment, which was significantly more effective than 1 mg/d of finasteride (mean difference, 7.1 hairs/cm²; 95% CI, 5.1-9.3 hairs/cm²), 0.25 mg/d of minoxidil (mean difference, 23.7 hairs/cm² ; 95% CI, 9.5-38.0 hairs/cm²), 5 mg/d of minoxidil (mean difference, 15.0 hairs/cm²;95% CI, 3.9-26.1 hairs/cm²) and 2% minoxidil solution (mean difference, 8.5 hairs/cm².

The greatest increase in terminal  hair count at 24 weeks was seen with 5 mg/d of minoxidil, which was significantly more effective than the 0.25 mg/d dose (mean difference, 43.6 hairs/cm²; 95% CI, 29.7-57.7 hairs/cm²), 2% solution (mean difference, 29.3 hairs/cm²; 95% CI, 21.1-37.5 hairs/cm²), 5% solution (mean difference, 29.8 hairs/cm²;95% CI, 19.7-39.8 hairs/cm²), and 1 mg/d of finasteride (mean difference, 10.4 hairs/cm²;95% CI, 2.2-18.6 hairs/cm²).

The greatest increase in total hair count at 48 weeks was with 5 mg/d of finasteride, which was significantly more effective than 2% topical minoxidil (mean difference, 20.7 hairs/cm²; 95% CI, 9.5-31.9 hairs/cm²). The greatest increase in terminal hair count at 48 weeks was with 1 mg/d of finasteride, which was significantly more effective than 2% topical minoxidil (mean difference, 32.1 hairs/cm²; 95% CI, 23.9-40.3 hairs/cm²) and 5% topical minoxidil (mean difference, 26.2 hairs/cm²;95% CI, 16.2-36.2 hairs/cm²).

The study was limited by possible selection bias involved in using hair count as an end point and by limited generalizability of results since no studies included in the analysis had exclusion criteria for participant race and ethnicity, the investigators noted.

“One possible ranking of efficacies–in decreasing order–is 0.5 mg/d of oral dutasteride, 5 mg/d of oral finasteride, 5 mg/d of oral minoxidil, 1 mg/d of oral finasteride, 5% topical minoxidil, 2% topical minoxidil, and 0.25 mg/d of oral minoxidil,” the study authors wrote, adding that future randomized clinical trials are needed to further support this order.

Reference

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. Published online February 2, 2022. doi:10.1001/jamadermatol.2021.5743