DHT (Dihydrotestosterone) is a hormone in the body which is important for the development of male external genitalia before birth and male sex characteristics like facial hair, deep voice & muscle growth. In females, increased levels of DHT cause excess facial hair, abnormal changes in genital organs & absence of monthly periods. DHT Free levels indicate the amount of hormone available to act on the tissues of your body. This test is used to check for delayed or precocious puberty in boys; erectile dysfunction in males; reduced libido in males & hirsutism in females.