Winstrol is a synthetic anabolic steroid approved by the FDA for human use. It is derived from testosterone. Winstrol has high oral bioavailability, because it survives thanks to liver metabolism and is therefore present in tablet form. As a final product does not produce estrogen. Winstrol is popular with female bodybuilders because of its great anabolic effect and weak androgenic effects; however, virilization and masculinization are the most common side effects. It is prohibited by Winstrol, IAAF and many other sports bodies for use in sporting events. Winstrol is popular in bodybuilders due to its anabolic effects; because it tends to retain lean body mass without any water retention and weight loss. Winstrol is also thought to be a fatty tissue burner, but there is little evidence to support it. It is used for anabolic effects to strengthen the masculine appearance by bodybuilders. It is clinically used in the treatment of human anemia and hereditary angioedema with remarkable success and is very popular among physicians. It was used in veterinary medicine to increase body mass in weak animals and increase blood count and appetite. Winstrol was used to provide a metabolic support in horse racing during the preparation of the race.