Winstrol is a popular brand name for the synthetic anabolic steroid Stanozolol, first patented in U.S. by Sterling back in 1962. The compound itself is a derivate of dihydrotestosterone, although its activity is much milder than this androgen in nature. It is technically classified as an anabolic steroid, shown to exhibit a slightly greater tendency for muscle growth than androgenic activity in early studies. While dihydrotestosterone really only provides androgenic side effects when administered, Stanozolol instead provides quality muscle growth. Admittedly the anabolic properties of this substance are still mild in comparison to many stronger compounds, but it is still a reliable builder.
Structurally Stanozolol is not capable of converting into estrogen. Likewise an antiestrogen is not necessary when using this steroid, gynecomastia not being a concern even among sensitive individuals. Since estrogen is also the culprit with water retention, instead of bulk Stanozolol produces a lean, quality look to the physique with no fear of exceed subcutaneous fluid retention. This makes it a favorable steroid to use during cutting cycles, when water and fat retention are a major concern. It is also very popular among athletes in combination strength/speed sports such as Track and field. In such disciplines one usually does not want to carry around excess water weight, and may therefore find the raw muscle-growth brought about by Stanozolol quite favorable over the lower quality mass gains of more estrogenic agents.
As mentioned Stanozolol is prepared in two distinct forms, as an oral tablet and an injectable solution. Although they are chemically identical, the injectable usually allows the user to take much higher dose of the steroid. This is of course because the injectables are much more cost effective, and therefore usually the preferred form of administration. You may find big differences in the appearance on the injectable product to another however. In particular there are big discrepancies in the size of the steroid particles used to manufacture the various stanozolol suspensions.