Proscar (generic: finasteride) is a prescription medication used to treat symptoms of prostatic hyperplasia (BPH), or enlargement of the prostate gland, in men. Proscar belongs to a group of drugs called 5-alpha-reductase inhibitors, which block the conversion of testosterone to DHT. DHT causes the prostate to enlarge, so by reducing the amount of DHT, Proscar can help decrease the size of the prostate.

This medication comes in tablet form and is taken once a day, with or without food.

Common side effects of Proscar include trouble getting or keeping an erection, decrease in sex drive, and decreased volume of ejaculate.