Mesterolone is an orally applicable androgen, and DHT derivative. It is sold under the brand name Proviron, by Schering. In the late 70's and early 80's it was used with some success in controlled studies of men suffering from various forms of depression.
This drug has good binding to the androgen receptor, but in muscle tissue most of it never reaches the androgen receptor because it is enzymatically converted to the diol. Thus, it is not an effective anabolic. It is somewhat effective as an anti-gyno agent, however, and appears to reduce estrogenic bloating if that problem exists.
Proviron reduces either levels of estrogen or the effect of estrogen. Thus, it is useful for avoiding gynecomastia, although it probably should not be relied upon as the sole drug for that. It is not hepatotoxic. It has the usual side effects of anabolic/androgenic steroids, with the added effect that it is particularly prone to cause erections.
Proviron is 5-alpha reduced and not capable of forming estrogen, and also has a very high affinity for binding to the aromatase enzyme (the enzyme responsible for converting all that good testosterone in your body into all that nasty estrogen). That means if you choose to take proviron with testosterone and/or any aromatizable steroid, it should actually serve to prevent estrogen build up by the aforementioned binding to the aromatase enzyme, which prevents aromatase from doing it´s dirty work and making a bunch of estrogen out of the other steroids you are taking. It should also be noted that Proviron also binds very well to SHBG (Sex Hormone Binding Globulin& a hormone responsible for reducing the amount of circulating free testosterone in your body). It bounds to SHBG better than any other drug studied. Proviron bounds to the Anabolic Receptor better than any oral anabolic , having an ability to bind to the AR better then testosterone, but not as well as Nandrolone. It´s important to remember that DHT and DHT derived compounds are used quite successfully to treat gynocomastia, and in this area, Proviron is no different.
Androgen Receptors are found in fat cells as well as muscle cells, and while they act on the AR in muscle cells to promote growth, they also act directly on the AR in fat cells to affect fat burning. The stronger the androgen binds to the A.R, the higher the lipolytic (fat burning) effect on adipose (fat)tissue. As if that´s not enough good news, some steroids (notably, testosterone) even increase the numbers of A.R. in muscle and fat. Thus, if you are taking a simple stack of proviron and testosterone, you´ll have more of the test you shoot as free testosterone floating around building muscle (compliments of the Proviron), more androgen receptors to be bound to (compliments of your testosterone) by your Proviron, thus causing more fat loss. Testosterone and Proviron are a very nice synergistic stack, pretty nearly an "ideal" stack of an oral and injectable, because both drugs will actually act to enhance the effect of the other.
So what we have here is a steroid which can basically make other steroids more effective by preventing their conversion into estrogen, as well as increasing the amount of circulating free testosterone in your body. This of course all provides a more hardened and quality look to muscles. Proviron is very much a "synergistic" drug in this respect, and it´s inclusion in any cycle would definitely make all of the other steroids perform better, and provide better gains. This is all compounded by the fact that proviron is a very lipolytic (fat-burning) drug.
Proviron can positively affects your HPTA (Hypothalamic-Pituitary-Testicular-Axis), the thing that regulates the male hormonal system. When a reasonable dose of this stuff is given (100-150mgs/day), it had no depressing effect on low or normal serum FSH and LH levels. Follicle Stimulating Hormone (FSH) and Leutenizing Hormone (LH) are two hormones which send a signal to your testes to produce testosterone. Good news for people considering it for PCT is that it can even raise your LH! Thus, by not suppressing those hormones and maybe even raising some, your normal testosterone levels will remain intact. This points to a novel use for this compound during Post-Cycyle-Therapy for a non-suppressive "bridge" between cycles. In fact, in yet another study, administration of Proviron (basically the same dose as in the last study) produced no changes in steroids, thyroid hormones, gonadotropins nor PRL (Prolactin Levels& you want those to remain low).
Effective Dose: 25-200mgs/day
Active Life: up to 12 hours
Detection Time: 5-6weeks
Androgenic: Anabolic Ratio:30-40/100-150
Store in temperature not exceeding 77oF(25oC).