This is a tidbit taken right off
www.steroid.com/proviron.php, I love this site because they provide tons of references for everything they claim. Here goes:
"Letīs delve into some of the positive points of this drug before we go any farther. Androgen Receptors are found in fat cells as well as muscle cells(5), and whilethey act on the AR in muscle cells to promote growth, they also act directly on the AR in fat cells to affect fat burning.(9)(3) The stronger the androgen binds to the A.R, the higher the lipolytic (fat burning) effect on adipose (fat)tissue(6)(2). As if thatīs not enough good news, some steroids (notably, testosterone) even increase the numbers of A.R. in muscle and fat (9)(7). Thus, if you are taking a simple stack of proviron and testosterone, youīll 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 itīs 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."
Aside from all this, my competitive friends have all told me roughly the same, take 50-75mg proviron daily and you'll have amazing results with whatever you're taking, these guys go through bottles of proviron like crazy. But above is the science behind it, in layman's terms, proviron basically opens up your body's AR receptors and allows you to use more of them (very crude explanation, I know) proviron also acts locally as a fat burner.