Men need to maintain a steady level of testosterone, because it is the hormone is responsible for the normal growth and development of male sex organs, and the maintenance of secondary sex characteristics.

In men, testosterone is made in significant amounts by the testicles. In women, small quantities of testosterone are made by the ovaries. In both men and women, testosterone is made in small amounts by the adrenal glands.

Low levels of testosterone may lead to anxiety, depression, confusion, or a decreased sex drive. Inadequate levels of testosterone may also result in a decline in muscle mass and strength, and an increase in upper body and abdominal fat.