RECENTLY, the Food and Drug Administration (FDA) approved the use of the drug finasteride (Proscar) under a new name, Propecia, for treatment of male pattern baldness. Although the generic term for the drug is finasteride, it is marketed under these 2 different proprietary names. The Proscar pill is 5 mg and the Propecia pill, 1 mg. Proscar is prescribed for older men suffering from benign prostatic hyperplasia. It is not surprising that Proscar affects hair growth since it inhibits the normal conversion of testosterone to dihydrotestosterone (DHT). It is also known that impotence is connected to levels of DHT.
Frankel S. Study of the Food and Drug Administration Files on PropeciaDosages, Side Effects, and Recommendations. Arch Dermatol. 1999;135(3):257-258. doi:10.1001/archderm.135.3.257