Steroids are synthetic forms of the male sex hormone testosterone.
The effect of testosterone in the body is to stimulate the development of bone, muscle, skin, hair growth, lowering of the voice, and emotional responses. When too much testosterone is produced, the body can react by shutting down skeletal growth mechanisms. The use of steroids for medical reasons accounts for approximately three million prescriptions a year in the United States to treat certain anemic conditions, protein anabolism and some gynecologic conditions. Non-medically, steroids are used to build muscle and increase strength, and have a high abuse potential. The 1994 National Household survey estimates that over one million people in the U.S. use steroids.