Finasteride is the generic name of the brand name drug Proscar. A drug that binds with the type 2 5-Alpha Reductase enzyme to reduce the amount of DHT in the prostate and serum. Proscar is manufactured by Merck and is FDA approved for the treatment of benign prostate enlargement. More recently 1mg tablets of finasteride have been marketed under the brand name Propecia as a treatment for hairloss.