Testosterone is a steroid hormone (androgen) made by the testes in males. The production of testosterone is stimulated and controlled by luteinising hormone (LH), which is manufactured in the pituitary gland.
In men, testosterone stimulates the enlargement of the penis, growth of body hair, muscle development, and a deepening voice. It is present in large amounts in boys during puberty and in men to regulate the sex drive and maintain muscle mass.
In women testosterone levels are about one tenth of those in men. Testosterone is produced both in small amounts from the ovary and by conversion from other weak androgens in the body.
Testosterone is also produced by the adrenal glands in both men and women.
