Anabolic steroids are synthetically produced variants of the naturally occurring male hormone testosterone. Both males and females have testosterone produced in their bodies: males in the testes, and females in the ovaries and other tissues. The full name for this class of drugs is androgenic (promoting masculine characteristics) anabolic (tissue building) steroids (the class of drugs). Some of the common street (slang) names for anabolic steroids include arnolds, gym candy, pumpers, roids, stackers, weight trainers, and juice. Currently, there are more than 100 different types of anabolic steroids (steroizi) that have been developed, and each requires a prescription to be used legally in the United States. Anabolic steroids can be taken orally, injected intramuscularly, or rubbed on the skin when in the form of gels or creams. These drugs are often used in patterns called cycling, which involves taking multiple doses of steroids over a specific period of time, stopping for a period, and starting again. Users also frequently combine several different types of steroids in a process known as stacking. By doing this, users believe that the different steroids will interact to produce an effect on muscle size that is greater than the effects of using each drug individually.