Winstrol or stanozolol is a synthetic anabolic steroid which resembles testosterone. Stanozolol is both an anabolic and androgenic hormone. In females it does cause virilizing effects.

Once widely available on the market, today it is a difficult product to find. Despite the hype on cyberspace about Winstrol being available, there have been many incidences of fake formulations or contaminants in products bought over the internet.