What is finasteride?

Finasteride prevents the conversion of testosterone to dihydrotestosterone (DHT) in the body. DHT is involved in the development of benign prostatic hyperplasia (BPH) and hair loss. Finasteride is used to treat benign prostatic hyperplasia (enlarged prostate). Finasteride is also used to reduce hair loss due to male pattern baldness. Finasteride may also be used for purposes other than those listed in this medication guide.