The role of dihydrotestosterone in benign prostatic hyperplasia

The enzyme 5-reductase converts intraprostatic testosterone into the potent androgen dihydrotestosterone (DHT). Hereditary defects in 5-reductase prevent the development of benign prostatic hyperplasia. Recently, an inhibitor of 5-reductase, finasteride, has been shown to decrease prostatic volume by 20–30% and improve urination in men with established BPH.