Stanozolol (abbrev. Stz), sold under many brand names, is an androgen and anabolic steroid (AAS) medication derived from dihydrotestosterone (DHT). It is used to treat hereditary angioedema. It was developed by American pharmaceutical company Winthrop Laboratories (Sterling Drug) in 1962, and has been approved by the U.S. Food and Drug Administration for human use, though it is no longer marketed in the USA. It is also used in veterinary medicine. Stanozolol has mostly been discontinued, and remains available in only a few countries