At normal body levels, testosterone triggers the onset of male secondary sexual characteristics during puberty and boosts muscle development and growth. Used medically to supplement normal hormone levels after injury or disease, steroids are also used illegally by bodybuilders and others to increase muscle mass, reduce body fat, and enhance endurance.
Steroids are available in both pill and liquid form for injection.
Steroids have lived in the shadows of professional and amateur sports for decades, due to the explosive physical changes they trigger. Psychological effects are also part of their draw, and range from euphoria and increased motivation to inflated feelings of self-esteem. Steroids are used medically to rebuild tissues weakened by injury or disease, to assist in regaining or maintaining weight after illness, and to aid recovery from breast cancer and osteoporosis in women. Steroids are a controlled substance under provisions of the Anabolic Steroids Control Act of 1990. In addition, a related chemical, human growth hormone, is now also controlled.