Finasteride cream in hirsutism

To determine, in a preliminary study, whether women with hirsutism attributable to various causes would benefit from treatment with finasteride cream.

Finasteride cream (0.25%) and placebo cream were administered to eight women with various degrees of facial hirsutism. The two creams were used on opposite sides of the face in an area of excessive hair growth. The side chosen for the finasteride cream versus placebo was randomized and blinded. In a 1 cm2 area on each side of the face, hair counts were done every 2 months throughout the 6-month study period. Hair thickness was also measured.

Hair follicles respond to testosterone by the conversion of this androgen to dihydrotestosterone through the action of 5a-reductase. Finasteride partially blocks this enzyme. Because of the easy solubility of this medication through the skin, a cream applied to the area of hair growth would be expected to decrease hirsutism locally. After a 6-month period, mean hair counts decreased significantly from 27.5 to 15.5 (P<0.05) in the finasteride-treated sites but showed no significant change from baseline in the placebo-applied sites. Moreover, the mean thickness of the measured hairs (in hundredths of millimeters) was significantly different between the placebo and finasteride-treated sites (4.33 versus 3.11, respectively; P<0.001).

In this study of women with facial hirsutism, topically applied finasteride significantly decreased hair growth and thickness, and no adverse effects were noted.