The Effects of Testosterone on the Human Male

Testosterone is a hormone that is produced in the testes in males and regulated by the hypothalamus and anterior pituitary gland. Women have small amounts of testosterone as well; however, testosterone is primarily responsible for the sexual development of males.

Production of testosterone begins to rise during puberty and peaks in males' early twenties, as boys begin to mature and develop secondary sex characteristics. Testosterone can have a varying effect on males as its production levels rise and fall, causing males to experience a wide range of physical and psychological side effects.

Sexual Effects

One of the main functions of testosterone is to develop and maintain sexual functions, including puberty, sex organs and the production of sperm. Testosterone is also responsible for a heightened libido and phallic growth during adolescence. After puberty, testosterone maintains sexual functions.

Secondary Sex Characteristics Effects

Testosterone plays a large role in the development of secondary sex characteristics in males, including deepening of the voice, increased muscle mass, broadened shoulders, growth of an Adam's apple, and body and facial hair. The hormone also affects bone density.

Psychological Effects

Men who have an imbalance of testosterone production can suffer a wide range of psychological side effects. Some males who produce too much testosterone seem aggressive, irritable and experience other types of mood swings. An insufficient amount of testosterone in males can cause depression, lethargy, mood swings and a loss of interest in sex. Mood swings are one of the main warning signs for a male to see his physician to test his testosterone levels.