Steroids or, more precisely, androgenic anabolic steroids, are a class of drugs similar to the male hormone testosterone. These drugs have muscle-building (anabolic), masculinizing (androgenic) and mind-altering (psychoactive) effects. Steroids are manufactured by pharmaceutical companies. The drugs are also produced in uncontrolled laboratories.
Steroids were first developed in the 1930s to treat a male growth problem that affected physical development and sexual functioning. Today they are still prescribed for certain health conditions. Steroids are also used for non-medical reasons. Some bodybuilders use steroids to increase their muscle mass and strength, and some athletes use the drugs believing they will improve their physical performance.