Steroids are a synthetic version of the human hormone called testosterone. Testosterone stimulates the development of bones and muscle, promotes skin and hair growth, and can influence emotions and energy levels.
Anabolic steroids were first developed in the 1930s in Europe, in part to increase the physical strength of German soldiers. Anabolic steroids were tried by physicians for many other purposes in the 1940s and 1950s with varying success. Disadvantages outweighed benefits for most purposes, and during the later decades of the twentieth century medical use in North America and Europe was restricted to a few conditions.