Winstrol is an androgen and anabolic steroid (AAS) medication which was derived from dihydrotestosterone (DHT), it is used to treat hereditary angioedema. It is used in veterinary medicine. Stanozolol has mostly been discontinued, and remains available in only a few countries. It is given by mouth in humans or by injection into muscle in animals.
Unlike most injectable AAS, stanozolol is not esterified and is sold as an aqueous suspension, or in oral tablet form. The drug has a high oral bioavailability, due to a C17α alkylation which allows the hormone to survive first-pass liver metabolism when ingested. It is because of this that stanozolol is also sold in tablet form.
Stanozolol is one of the AAS commonly used as performance-enhancing drugs and is banned from use in sports competition under the auspices of the International Association of Athletics Federations (IAAF) and many other sporting bodies. Additionally, stanozolol has been used in US horse racing.