Testosterone is the primary male sex hormone, and its main function is to control male physical features. This hormone is created in the testes, and testosterone helps transform a boy into a man. Testosterone deepens the voice, builds muscle, strengthens bones, increases penis size and produces body hair, such as facial hair and pubic hair. Women also produce testosterone; however, women produce the hormone in much smaller amounts.
Men require a normal amount of testosterone to produce sperm and have children. This hormone plays a vital role in developing the prostate and male reproductive tissues, such as the testes and the penis. Testosterone promotes healthy secondary sexual characteristics, such as increased bone mass and sex drive. Additionally, a normal testosterone level is necessary for good health and the prevention of osteoporosis.
The level of testosterone in adult men is more than seven times the amount of testosterone in adult females, and the daily metabolic consumption of the hormone in men is 20 times greater than women. Poor nutrition, excessive exercise and illness lead to low testosterone. Low testosterone can cause a decrease in sex drive, reduced sperm count, poor erections and enlarged breasts. Symptoms of low testosterone can also lead to less energy.