Jerry Shapiro, Division of Dermatology
University of British Columbia, Vancouver, Canada
Study Information and Results:
Drake et al showed that median scalp and serum DHT levels decreased with 0.2 mg, 1 mg and 5 mg of finasteride after 42 days of treatment.
Roberts et al confirmed that finasteride 1 mg daily was the optimal dose, with 1 mg and 5 mg superior to lower doses such as 0.2 mg/day.
The 5 mg dose was not more efficacious than the 1 mg dose.
Three double-blind, randomized, placebo-controlled studies were conducted in 1879 men ages 18 to 41 years with mild to moderate hair loss. Two of the studies enrolled men with vertex hair loss and one with frontal hair loss. Finasteride 1 mg tablets or placebo tablets were taken once daily for 24 months in the vertex studies and 12 months in the frontal study. All three studies showed a significant hair count increase in men treated with finasteride, with a significant decrease in hair counts in men treated with placebo.
Finasteride stabilized hair loss in 83% of the cases with vertex hair loss atafter two years. and in 70% of cases for frontal hair loss after one year. The chances of mild to moderate visible regrowth are 61% on the vertex atfter 2 years and 37% on the frontal area after one year.
Van Neste et al. using the phototrichogram method provided direct evidence that finasteride 1 mg daily promotes the conversion of hairs into the anagen phase. A study of finasteride in 136 post-menopausal women with androgenetic alopecia (AGA) showed no benefit compared with placebo.
Finasteride is well tolerated and side effects are rare. Side effe ts include 1.8% decreased libido (1.3% placebo), 1.3 % erectile dysfunction (0.7% placebo) and 0.8% decreased ejaculate volume (0.4% placebo). There was no significant difference from the placebo group for each of these side effects taken alone, but there is a statistical difference when all side effects are considered together (3.8% vs 2.1%). Side effects will subside spontaneously in 58% most of those who decide to continue the treatment and are reversible upon cessation of treatment within days or a week.