"Anabolic Steroids" are any drug(s) (other then estrogens, progestins, and corticosteroids) or hormonal substance(s), chemically related to testosterone, a male hormone that promotes muscle growth. Today, there are more than 100 varieties of anabolic steroids that have been developed, but only a limited number have been approved for human or veterinary use, and each of them are Schedule III and require a prescription in order to be used medically in the United States. Many of the illegal steroids are smuggled in from other countries, illegally diverted from U.S. pharmacies, or synthesized in secret laboratories. Estimates show that there are more than $400 million worth of black-market (illegal) sales of steroids per year . For the most part, illicit steroid use is linked to athletic competitions and/or an athlete trying to gain a competitive edge ; but, sports and athletic competitions are not the only place steroids are used. Outside of sports, they are used because someone wants to alter his or her physical appearance, usually based on distorted perceptions that he or she is obese, underweight, too weak, or other personal views. Over the years, the popularity of steroids has varied, but in 2001, it was found that about 2% of high school students used steroids in the past year.