Mesterolone (Proviron) Profile

[The Anonymizer]

Proviron (mesterolone) is basically an orally active DHT (Dihydrotestosterone) preparation. For comparision, we can think of some other orally prepared DHT compounds like Winstrol, Anavar, etc& Those both act very similarly in mechanism to Proviron, but a more accurate way to think of this compound is as something like "Oral Masteron." As I´m sure you noticed, their anabolic/androgenic ratio is very similar.Remember, DHT is 3 to 4 times as androgenic as testosterone and is, of course, incapable of forming estrogen. Also, Proviron is quite unique in that a simple look at it´s 4-ring structure will show us that it is not going to be too liver toxic, since it is not c17-Alpha-Alkylated, as many orals are& this modification (lacking in Proviron) makes drugs more liver toxic. Proviron has a 1-metyhl group added, instead. Looks pretty great on paper, right? Well, as usual, things tend to look better on paper than they do in the body. Your body has a negative feedback loop which prevents your body from having too much DHT floating around(if you´ve been paying attention up to now from reading my other stuff, you already know this). An excess of DHT will eventually be changed into another (largely not anabolic) compound.
And of course, being a DHT-based compound, this stuff isn´t going to be great for female athletes to use. Virilization (development of male sexual characteristics) is going to be a concern for women daring enough to try this stuff. My advice is that there is much better, safer compounds for female athletes and bodybuilders to use.
So lets go back to the comparison with being some sort of "Oral Masteron"& basically since 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 I know you wouldn´t even be doing a cycle without including some form of 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)(1). As a matter of fact, in the last study I read, it bound to SHBG better than any other drug studied. Also, I´d like to note that Proviron bound to the Anabolic Receptor better than any oral anabolic (except for the insanely toxic MethylTrienolone), having an ability to bind to the AR better then testosterone, but not as well as Nandrolone (1). Unfortunately, as we know, DHT also has a high affinity for binding to receptors in the scalp and prostate, causing some possible nasty side effects, like male pattern baldness and prostate enlargement. 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.
Let´s 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 that´s 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, 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.
Now, as if all of this weren´t enough, let´s talk about how Proviron 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 (6). 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 (10)! 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). (8).
Unfortunately, this stuff is not too hot on it´s own. It´s a good drug for inclusion in a cycle containing testosterone and other armoatizable steroids, and it´s a good drug for a possible "bridge" between cycles. Alone, however, as an androgenic or anabolic agent, it´s effects have been very weak in both studies (9), as well as in the experience of everyone I spoke to about it. This may be due to the addition of the 1-methyl-group to DHT, which makes this stuff orally active. Whatever the case, as a stand alone anabolic or androgenic compound, it´s not too impressive.
This drug is a rare find on the American Black Market, and many Underground Labs don´t even produce it, but if you can find it, I´d say that you shouldn´t be paying more than .50cents for each 50mg tab.
Proviron (Mesterolone) Profile

[1 alpha-methyl-17 beta-hydroxy-5 alpha-androstan-3-one]
Molecular Weight: 304.4716
Molecular Formula: C20H32O2
Melting Point: N/A
Manufacturer: Schering
Release Date: 1960
Effective Dose: 25-200mgs/day
Active Life: up to 12 hours
Detection Time: 5-6weeks
Androgenic: Anabolic Ratio:30-40/100-150

References:

1. Relative binding affinity of anabolic-androgenic steroids: comparison of the binding to the androgen receptors in skeletal muscle and in prostate, as well as to sex hormone-binding globulin.Endocrinology. 1984 Jun;114(6):2100-6.
2. APMIS. 2000 Dec;108(12):838-46.
3. (Xu X, et al. "The effects of androgens on the regulation of lipolysis in adipose precursor cells." Endocrinology 1990 Feb;126(2):1229 ).
4. J Anim Sci. 1992 Nov;70(11):3381-90.
5. Am J Physiol. 1998 Jun;274(6 Pt 1):C1645-52.
6. The effect of mesterolone on sperm count, on serum follicle stimulating hormone, luteinizing hormone, plasma testosterone and outcome in idiopathic oligospermic men.Int J Gynaecol Obstet. 1988 Feb;26(1):121-8.
7. J Appl. Physiol.94 1153-61 2003
8. Effect of non aromatizable androgens on LHRH and TRH responses in primary testicular failure.Horm Metab Res. 1984 Sep;16(9):492-7.
9. [Androgen substitution in the andrological disease picture] Andrologia. 1983 May-Jun;15(3):283-6. German.
10. The effects of mesterolone, a male sex hormone in depressed patients (a double blind controlled study). Methods Find Exp Clin Pharmacol. 1984 Jun;6(6):331-7.