Proviron is a derivative of dihydrotestosterone. In clinical practice it is used to treat sexual dysfunction of various kinds, which are most often caused by a low level of endogenous testosterone. It can enhance potency and sexual interest and, in some cases, increase the sperm count. The drug does not stimulate the production of testosterone by the body, it simply replaces its lack. Proviron is not an ideal drug for growing muscle mass. It works in the best way in stack with other anabolic steroids such as testosterone. Proviron has antiestrogenic activity, i.e. prevents conversion of steroids into estradiol. The second advantage of proviron is that it greatly reduces sex hormone-binding globulin (SHBG), increasing amount of free (= bioavailable and active) testosterone in the blood. In fact, studies have shown that mesterolone is capable of binding to SHBG much stronger than any other steroid. Proviron as a derivative of dihydrotestosterone gives the muscles hardness and density, while at the same time contributing to the burning of excess fat, hence it`s an ideal choice for cutting cycles.