Finasteride for Androgenetic Alopecia
January 1998
in “
NEJM Journal Watch
”
TLDR Finasteride increases hair count in men with hair loss, but the effect isn't permanent and hair loss returns if treatment stops.
Finasteride, an inhibitor of type II 5α-reductase, has been found to be effective in reducing the conversion of testosterone to dihydrotestosterone (DHT) in hair follicles and the prostate. Two one-year, double-blind, randomized, controlled trials were conducted with 1,553 men with androgenetic alopecia. After one year of treatment with finasteride, scalp hair counts increased by about 80% from baseline, while those on placebo experienced a decrease of about 20%. Hair counts remained stable in men who continued finasteride for the second year, and those who switched from placebo to finasteride saw a 50% increase in hair counts. The treatment was well-tolerated, with only a small percentage of men experiencing decreased libido or erectile dysfunction. However, it is important to note that hair loss returns to baseline within six months of stopping finasteride, indicating that it is not a permanent solution.