Androgens Sources of androgens males testes are a major source of androgens adrenal cortex is a minor source of androgens females adrenal cortex is a major source of androgens Androgen biosynthesis adrenal cortex in adrenal cortex, zona reticularis synthesizes and secretes adrenal androgens via a biosynthetic pathway that begins with cholesterol login to view 1 more bullet testes Leydig cells of testes synthesize and secrete testosterone via a biosynthetic pathway that begins with cholesterol login to view 4 more bullets Leydig cells of testis may also synthesize and secrete dihydrotestosterone (DHT) login to view 2 more bullets androgenic target tissues in some androgenic target tissues, DHT is an active androgen login to view 2 more bullets Androgen potency DHT > testosterone > androstenedione Androgen function actions mediated by testosterone fetal differentiation of internal male genitalia login to view 1 more bullet pubertal growth spurt login to view 3 more bullets increased muscle mass cessation of pubertal growth spurt login to view 6 more bullets actions mediated by DHT fetal differentiation of external male genitalia login to view 1 more bullet male hair pattern and male pattern baldness sebaceous gland activity growth of prostate 5α-reductase inhibitors e.g., finasteride inhibit conversion of testosterone to DHT DHT mediates male hair pattern and growth of prostate 5α-reductase inhibitors may be used in treatment of benign prostatic hyperplasia (BPH) and hair loss in males Exogenous testosterone exogenous testosterone inhibits hypothalamic-pituitary-gonadal axis decreases testosterone levels in testes login to view 2 more bullets