Anabolic androgenic steroids (AAS) were initially created for therapeutic purposes, and synthetic derivatives of the male hormone testosterone. Due its great anabolic effects, these drugs are being used on a large scale, for the improvement of sports performance. In this present study, we aim to show the history of it’ use, present their mechanisms of action, more particularly its use correlate with improved body composition, muscle mass, aerobic capacity and verify their possible side effects, analyzing their use therapeutic and indiscriminate, through direct scientific research with the sports. Sources were reviewed scientific the following search engines: PUBMED, LILACS and SCIELO. The results showed that in presence of a suitable AAS and diet can contribute to increases in body weight, particularly lean body mass and muscle strength gains achieved by high intensity exercise, these effects can be further potentiated, the use of supraphysiological doses, but in the aspect of aerobic power, there are not scientific evidence to support their improvement. Regarding side effects, the use of AAS, is related to several complications in the liver, cardiovascular system, reproductive system and psychological characteristics, always assigned by the non-therapeutic and abuse of AAS. Thus we conclude that the use of AAS, are directly linked to gains muscle mass, strength, as well several side effects, always assigned to abusive and indiscriminate doses, it is noteworthy that the scientific literature, still has a certain lack of studies, mainly randomized, controlled, with supraphysiological doses in human, so many effects are still unknown.
The legal status of anabolic steroids varies from country to country. In the ., anabolic steroids are listed as Schedule III controlled substances under the Controlled Substances Act , which makes the possession of such substances without a prescription a federal crime punishable by up to seven years in prison.  In Canada, anabolic steroids and their derivatives are part of the Controlled drugs and substances act and are Schedule IV substances, meaning that it is illegal to obtain or sell them without a prescription. However, possession is not punishable, a consequence reserved for schedule I, II or III substances. Those guilty of buying or selling anabolic steroids in Canada can be imprisoned for up to 18 months. Importing or exporting anabolic steroids also carry similar penalties.  Anabolic steroids are also illegal without prescription in Australia,  Argentina, Brazil, and Portugal,  and are listed as Schedule 4 Controlled Drugs in the United Kingdom.
Michael A. Ball, DVM, completed an internship in medicine and surgery and an internship in anesthesia at the University of Georgia in 1994, a residency in internal medicine, and graduate work in pharmacology at Cornell University in 1997, and was on staff at Cornell before starting Early Winter Equine Medicine & Surgery located in Ithaca, . He is also an FEI veterinarian and works internationally with the United States Equestrian Team. Ball authored Understanding The Equine Eye , Understanding Basic Horse Care , and Understanding Equine First Aid , published by Eclipse Press and available at or by calling 800/582-5604.