Proviron is an oral DHT steroid compound similar to Masteron. Although it is not an ideal compound for building muscle (actually it is not good at all for this purpose), Proviron is helpful in stacks because of its unique ability to keep the body from turning testosterone into estrogen, thus giving the testosterone a better anabolic effect. This aids the bodybuilder in many ways. First, it helps reduce estrogenic side effects of other steroids water-retention, lowered sex drive, gynocomastia, etc. Also, Proviron can help boost the potency of testosterone in the body by freeing testosterone from its binding to sex hormone-binding globulin (SHBG).
Proviron is therefore best stacked with testosterone, which makes taking anti-estrogen compounds unnecessary. However, Proviron can cause high blood pressure so blood pressure medication may be required for those prone to hypertension.
Proviron the oral androgen mesterolone (1 methyl-dihydrotestosterone). Just as with DHT, the activity of this steroid is that of a strong androgen which does not aromatize into estrogen. In clinical situations Proviron is generally used to treat various types of sexual dysfunction, which often result from a low endogenous testosterone level. It can usually reverse problems of sexual disinterest and impotency, and is sometimes used to increase the sperm count. The drug does not stimulate the body to produce testosterone, but is simply an oral androgen substitute that is used to compensate for a lack of the natural male androgen.
Although this steroid is strongly androgenic, the anabolic effect of it is considered too weak for muscle building purposes. This is due to the fact that Proviron is rapidly reduced to inactive metabolites in muscle tissue, a trait also characteristic of dihydrotestosterone. The belief that the weak anabolic nature of this compound indicated a tendency to block the androgen receptor in muscle tissue, thereby reducing the gains of other more potent muscle building steroids, should likewise not be taken seriously. In fact due to its extremely high affinity for plasma binding proteins such as SHBG, Proviron may actually work to increase the activity of other steroids by displacing a higher percentage into a free, unbound state. Among athletes Proviron is primarily used as an anti-estrogen. It is believed to act as an anti-aromatase in the body, preventing or slowing the conversion of steroids into estrogen. The result is somewhat comparable to Arimidex (though less profound), the drug acting to prevent the buildup of estrogen in the body. This is in direct contrast to Nolvadex, which only blocks the ability of estrogen to bind and activate receptors in certain tissues. The anti-aromatization effect is preferred, as it is a more direct and efficient means of dealing with the problem of estrogenic side effects. Another disadvantage of Nolvadex is that if discontinued too early, a rebound effect may occur as high serum estrogen levels are again free to take action. This of course could mean a rapid onset of side effects such as gynecomastia. Most actually prefer to use both Proviron and Nolvadex, especially during strongly estrogenic cycles. With each item attacking estrogen at a different angle, side effects are often greatly reduced.