Dihydrotestosterone, or DHT, is a form of the hormone androgen that occurs when an enzyme called 5-alpha reductase transforms testosterone into a more potent hormone. It appears in both men and women and it is the hormone that helps the normal development of men, sexual performance and other activities like prostate growth. DHT is essential to the body, but it cannot be considered entirely beneficial; as the hormone builds up in the head, it may start decreasing the size of the hair follicles, which ultimately results in hair loss.