Oxymetholone (also known as anapolon or anadrol) is a very drastic synthetic steroid, 17-alpha-alkylated modification of dihydrotestosterone. It was developed for the treatment of osteoporosis and anaemia, as well as to stimulate muscle gain in malnourished and debilitated patients. Oxymetholone has been approved by the American Food and Drug Administration (FDA) for use in humans. Later there where created non-steroidal drugs that effectively could treat anaemia and osteoporosis; because of this anapolon lost his popularity and by 1993 Syntex decided to cease the production of the drug, as well as other manufacturers did.
The Mesterolone hormone is not estrogenic. It does not aromatize and it carries no progestin nature. As a result, the side effects of Proviron will not include any related effects such as gynecomastia or excess water retention. Such adverse effects are impossible with this steroid. This will also greatly reduce the risk of high blood pressure as high blood pressure associated with anabolic steroid use is often due to extreme water retention. In fact, Proviron should provide an anti-estrogenic effect by preventing testosterone to estrogen conversion or at least tremendously slow it down.