Anabolic steroids are synthetically-produced derivatives of testosterone, a natural hormone that, among other things, promotes muscle growth. There are a number of different types of manufactured steroids. The official name for this type of steroid is androgenic anabolic steroid, or in English, "a drug that promotes protein synthesis (anabolic) and leads to masculine secondary sexual characteristics (androgenic)."

To understand how anabolic steroids work, it helps to know how testosterone works. Testosterone is a male sex hormone (although women also produce it) that serves two basic purposes. During the first stage of puberty, young men produce an increased amount of testosterone for a number of months. During this stage, the bulk of the male physical maturation process occurs including bone growth, deepening of voice, and development of facial and body hair. Testosterone also maintains the male reproductive system and helps to produce larger body size and muscle mass.

Androgenic steroids are prescribed by doctors for therapeutic treatment of conditions where testosterone (or its effects) need to be added or replaced. Anabolic steroids are designed to copy the muscle-building effects of testosterone but with fewer of the accompanying "masculinization" effects.

Users of anabolic steroids can be divided into two groups:

  • Those who use them for medical purposes
  • Those who use them to enhance their strength and athletic ability, and/or enhance their physical appearance by adding muscle mass

Anabolic steroids are prescribed for a small number of legitimate medical purposes. These include the treatment of:

  • People with significant weight loss due to extensive surgery, trauma, HIV, cancer, or other conditions
  • Bone pain accompanying osteoporosis