Androgens are a group of chemically-related male sex hormones. They can be produced naturally by the body or be manufactured synthetically and then administered to the individual. Androgens belong to a group of hormones called steriod hormones. Testosterone is the most abundant androgen in the male body.

Testosterone is responsible for the development of male sexual characteristics. In normal males, it is produced at the onset of puberty by the testes in response to stimulation by hormones called gonadotrophins that originate in the anterior pituitary gland and the hypothalamus, a part of the brain.

Testosterone causes boys to acquire the sexual characteristics of men. In response to testosterone, the penis, testes, and scrotum grow and the voice deepens. Hair grows on the body and face and the skin becomes coarser. Androgens also stimulate growth. Not only do boys grow taller during puberty, they also develop larger, bulkier muscles...