Proviron (Mesterolone), the active ingredient is Mesterolone. Chemical name: 17b-hydroxy-1a-methyl-5a-androstan-3-one-1-methyl-5a-dihydrotestosterone. A hormonal drug with moderate androgenic activity and significantly improves erectile function. It appeared in 1934 and, despite its longevity, remains a unique anabolic.


The drug has less liver toxicity, which in turn makes it possible to take Proviron in combination with other anabolic tablets during the steroid cycle.
Its action is aimed at blocking the transformation of testosterone into estrogen, but its effectiveness in this regard is very low. Therefore, its action is not equal to that of aromatase inhibitors (it cannot cope with the continuous aromatization). However, Proviron can desensitize estrogen receptors, further increasing its effectiveness by decreasing circulating estrogen.

A more important effect is the suppression of sex hormone binding globulin. This increases the effectiveness of the cure by increasing the amount of free testosterone in the blood. It happens when the testosterone in the human body is 80-98% inactive due to globulin and albumin, which bind to the sex hormone and prevent the release of testosterone. And the participation of proviron in this ballet leads to the fact that dihydrotestosterone, which has a greater affinity for these proteins than testosterone, binds to globulin and albumin, releasing a large amount of free testosterone and this leads to a better anabolic activity. The reduction in SHBG helps to increase the cure result.

Proviron for men

Proviron for men

The drug reduces the side effects of steroids related to the male reproductive system, helps not to lose libido and maintain erectile function. Mesterolone is related in the event that a reduction in SHPG cannot be achieved without resorting to this drug. It is generally used as part of a range of steroids. As an independent drug, it is not used, as it does not have special anabolic properties. It is not suitable for building muscle mass. But as a preparatory step for serious steroids, its use is justified.
At the same time, Mesterolone is used in the general course of steroids to increase androgenicity (it’s good and bad – an individual approach is used). Therefore, Proviron is often used in combination with steroids such as nandrolone and trenbolone, which have a weak androgenic effect. This combination gives a pleasant and predictable result: an increase in libido. DHT plays a key role in enhancing libido which is why Proviron is used along with these steroids to weaken or lessen the insidious side effect.

Proviron in bodybuilding is often used for competitions. Significantly improves muscle relief. Such a positive effect is due to the low level of regulation of estrogen receptors in muscle tissue, which leads to a decrease in the water balance of the body, which gives a visual effect of dry, high-quality and hard muscles. This drug on the course of testosterone helps during drying. It enhances the effect of the hormone on the body, allows the athlete to relax a little in the diet without switching to protein alone.

Proviron on the course. Side effects

Proviron. Side effects

The drug in a number of steroids is considered one of the safest. The side effect on the male body is insignificant or completely absent. But for women, it can cause a lot of problems. After application, hair growth may increase in different parts of the body, the voice becomes rougher, the appearance is more masculine. It can also increase the level of cholesterol in the blood, increase pressure, rashes may appear on the body. The hair on the head may begin to fall out. In women, the drug can also cause infertility.