View Full Version : Proviron~mesterolone

12-27-2010, 02:22 PM
Proviron® (mesterolone)

Androgenic 30-40
Anabolic 100-150
Standard Testosterone propionate
Chemical Names 17beta-hydroxy-l alpha-methyl-Salpha-androstan-3-one l-methyl-Salpha-dihydrotestosterone
Estrogenic Activity none
Progestational Activity not significant


Proviron® is Schering's brand name for the oral androgen mesterolone (1-methyl dihydrotestosterone). Similar to dihydrotestosterone, mesterolone is a strong androgen with only a weak level ofanabolic activity.This is due to the fact that like dihydrotestosterone, mesterolone is rapidly reduced to inactive diol metabolites in muscle tissue where concentrations of the 3-hydroxysteroid dehydrogenase enzyme are high. The belief that the weak anabolic nature of this compound indicates a tendency to block the androgen receptor in muscle tissue, thereby reducing the gains of other more potent muscle-building steroids, should likewise not be taken seriously. In fact, due to its extremely high affinity for plasma binding proteins such as SHBG, mesterolone may actually work to potentate the activity of other steroids by displacing a higher percentage into a free, unbound state. Among athletes, mesterolone is primarily used to increase androgen levels when dieting or preparing for a contest, and as an antiestrogen due to its intrinsic ability to antagonize the aromatase enzyme.


According to company literature, Schering developed Proviron® in 1934, making this is an extremely old medication as far as anabolic/androgenic steroids. Schering also states that it was the first medication put into clinical practice for the treatment of "hormone-related diseases and complaints in men."Accordingly, mesterolone would have been developed around the same time as methyltestosterone (1935) and testosterone propionate '(1937), which are both very old agents generally considered obsolete by today's standards. In spite of its age, Proviron has a long history of clinical effectiveness and , safety, and remains in widespread clinical use today. It is generaly prescribed to males for the treatment of declining physical and mental capacity caused by age and subnormal androgen levels, low libido caused by insufficient androgen levels, hypogonadism (in pre-and post-pubescent males), and infertility (in certain situations mesterolone increases the quality and quantity of sperm).

The use of mesterolone as a fertility aid is perhaps one of the most controversial indications for this drug considering that anabolic/androgenic steroids are generally linked to infertility. It is also a use of mesterolone that is quite often misunderstood by athletes. Mesterolone is applicable here because it is an effective androgen that offers minimal suppression of gonadotropins in normal therapeutic doses, not because it increases LH output. Absent gonadotropin suppression, the drug may supplement androgenicity necessary for sperm production. It is well understood that androgens have direct stimulatory effects on spermatogenesis, and also influence the transportation and maturation of sperm via effects on the epididymis, ductus deferens, and seminal vesicles. So the role of these hormones is not entirely suppressive. Mesterolone seems to have a unique positive influence on certain cases of male fertility because its potential stimulatory effects on sperm quantity and quality are not overridden by the suppression of gonadotropins.

Mesterolone is widely manufactured by Schering, which currently sells the drug in more than thirty countries worldwide.The most common brand name used for its sale is Proviron, although Schering has sold the agent under other names in certain markets, including Mestoranum and Provironum. Additionally, other manufacturers have sold mesterolone over the years, appearing under such brand names as Pluriviron (Asche, Germany), Vistimon (Jenepharm, Germany), and Restore (Brown & Burke, India). In spite of its long track record of safety and efficacy, mesterolone was never approved for sale in the United States. It remains available in many Western nations, however. Schering remains the major (almost exclusive) global supplier of mesterolone today, although on rare occasion other brands of the drug can be located.

How Supplied:

Mesterolone is widely available in human drug markets. Composition and dosage may vary by country and manufacturer; preparations generally contain 25 mg or 50 mg of steroid per tablet.

Structural Characteristics:

Mesterolone is a modified form of dihydrotestosterone. It differs by the addition of a methyl group at carbon 1, which helps protect the hormone from hepatic metabolism during oral administration. The same structural modification is also used with oral Primobolan® (methenolone) tablets. Alkylation at the one position slows hepatic metabolism of the steroid during the first pass, although much less profoundly than c-17 alpha alkylation. Mesterolone is resistant enough to breakdown to allow therapeutically beneficial blood levels to be achieved, although the overall bioavailability remains much lower than c-17 alpha alkylated oral steroids. Mesterolone also has a very strong binding affinity for Sex Hormone Binding Globulin.71o This may act to displace other steroids more weakly bound to SHBG into a free (active) state.

Administration (Men):

To treat androgen insufficiency, mesterolone is usually given in a dose of 1 tablet (25 mg) three times per day at the initiation of therapy. The drug is later continued at a lower maintenance dose, which usually consists of taking 1 tablet (25 mg) one to two times per day. Similar doses are used to support male fertility, usually in conjunction with other fertility drugs like injectable FSH. The usual dosage among male athletes is between 50 mg and 150 mg of mesterolone per day, or two to six 25 mg tablets. The drug is typically taken in cycles of 6-12 weeks in length, which is usually a sufficient period of time to notice the benefits of drug therapy.

Many bodybuilders favor the use of mesterolone during dieting phases or contest preparation, when low estrogen and high androgen levels are particularly desirable. This is especially beneficial when anabolics like Winstrol®, Anavar, or Primobolan® are being used alone, as the androgenic content of these drugs is relatively low. Mesterolone can be effectively used here to adjust the androgen to estrogen ratio upwards, bringing about an increase in the hardness and density of the muscles, supporting libido and general sense of well being, and increasing the tendency to burn body fat. It is also commonly used (at a similar dosage) to prevent gynecomastia when other aromatizable steroids are being administered, often in conjunction with 10-20 mg per day of Nolvadex.

Administration (Women):

Mesterolone is not approved for use in women.This agent is not recommended for women for physique-or performance-enhancing purposes due to its strong androgenic nature and tendency to produce virilizing side effects. Some women do favor the drug, however, and find a single 25 mg tablet enough to efficiently shift the hormone balance in the body, greatly impacting the look of definition to the physique. Intake is usually limited to no longer than four or five weeks in such situations to minimize the chance of developing lasting virilizing effects. One tablet used in conjunction with 10 or 20 mg of Nolvadex® can be even more efficient for muscle hardening, creating an environment where the body is much more inclined to burn off extra body fat, especially in female trouble areas like the hips and thighs. Extreme caution should be taken with such use, however.

Llewellyn’s W. (2009). Anabolics (9th ed), Proviron® mesterolone(pp. 369-371): Jupiter, FL: Molecular Nutrition

12-27-2010, 02:23 PM


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


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.
APMIS. 2000 Dec;108(12):838-46.
(Xu X, et al. "The effects of androgens on the regulation of lipolysis in adipose precursor cells." Endocrinology 1990 Feb;126(2):1229 ).
J Anim Sci. 1992 Nov;70(11):3381-90.
Am J Physiol. 1998 Jun;274(6 Pt 1):C1645-52.
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.
J Appl. Physiol.94 1153-61 2003
Effect of non aromatizable androgens on LHRH and TRH responses in primary testicular failure.Horm Metab Res. 1984 Sep;16(9):492-7.
[Androgen substitution in the andrological disease picture] Andrologia. 1983 May-Jun;15(3):283-6. German.
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.

steroid.com-Anthony Roberts

12-27-2010, 03:13 PM
Women and Proviron

*Note: *caveat about this is "typical" and not medically recommended*

Proviron Overview
Proviron has primarily androgenic properties (versus anabolic properties), meaning it is great for hardening, particularly in the abs area, but not really for muscle building.

Typical Use
Proviron is often used towards the end of a competition prep, along with Nolvadex, to tighten up in the mid-section. Because of its very androgenic nature, like Nolvadex, it is not something you would use as a "maintenanc protocol for fat loss". It is still a steroid and not a "fat loss aid".

Typical Cycle
- Dosage: 25 mg per day, split into 1/2 in the AM, and 1/2 in the PM.
- Cycle duration: 4-8 weeks max
- Commonly stacked with Nolvadex, at 20 mg per day, 1/2 in the AM and 1/2 in the PM.

Typical Sides
Note that most of these sides would be present from any other compounds being cycled as part of contest prep or low bodyfat as part of contest prep.
- acne
- interrupted menstrual cycle

01-03-2011, 03:20 PM
Anabolic Pharmacology

By Seth Roberts


Pharmacology is the study of drugs and their effects. Anabolic Pharmacology is the study of drugs that have a growth promoting effect in muscle. This column will explore Anabolic Pharmacology by profiling a different anabolic drug and its effects each month. The focus of discussion this month will be the anabolic androgenic steroid, Proviron:

Mesterolone is a simple derivative of dihydrotestosterone and is commonly known by its trade name, Proviron. The addition of a methyl group to the 1 position, like methenolone, should help to provide a small amount of protection from metabolism when taken orally. In fact the only difference between methenolone and mesterolone is the presence of a double bond in the 1,2 position with methenolone. This double bond changes the shape of the A-ring as well as the location of the 1-methyl group. Though these drugs are so similar in appearance, they are quite different in activity. While the 1-methyl and 1-double bond help to keep methenolone from being metabolized to inactive metabolites, the presence of only a 1 methyl group seems to provide mesterolone with little protection and it is likely deactivated quickly.

Since mesterolone is already 5-alpha reduced, it is not subject to further metabolism by 5-alpha reductase. Mesterolone, as a DHT-derivative, cannot be converted by aromatase to estrogenic metabolites and has some degree of inhibition of aromatase and likely some inhibition of 5-alpha reductase as well. In fact, many consider mesterolone to be an anti-estrogen, and its use in the literature seems to support this to some degree. Mesterolone is one of the strongest binder of SHBG commercially available, in fact, only DHT binds to SHBG more strongly1,2. As discussed earlier, SHBG plays a very important role in testosterone metabolism. Because mesterolone binds so strongly to SHBG it tends to bump other less strongly bound molecules in the ??free? state where they can bind the androgen receptor3. Therefore, some athletes have attempted to use mesterolone for this purpose. They add mesterolone to a cycle if the hopes that more steroid will remain free and active. This would also be true for testosterone and estrogen.

Mesterolone would be capable of bumping both of these hormones into circulation as well which may result in androgenic or estrogenic effects. There is no evidence that mesterolone binds to glucocorticoid or progesterone receptors. Mesterolone is not known for being very anabolic even though the anabolic to androgenic ratio when given subcutaneously is favorable. When given orally, mesterolone undergoes significant metabolism that greatly reduces any anabolic effect4. The fact that mesterolone has been shown to have little effect on red blood cell production, unlike other androgens, seems to confirm its rapid metabolism5. Mesterolone has been studied quite extensively in the literature as a fertility treatment to increase sperm quantity. There is quite a bit of conflicting data showing mesterolone to have variable effects on LH and FSH, though it is generally been shown to not reduce normal levels of LH and FSH6. Though its use as an SHBG binder is somewhat questionable, it may have use in blocking the metabolism of other DHT derivatives by 3-alpha hydroxysteroid dehydrogenase since it seems to have significant affinity for this enzyme.

Seth Roberts is a former pharmaceutical research scientist with over ten years of pharmacological research in the discovery and development of novel therapeutics. If you want to learn more about Anabolic Steroids, pick up Seth??s new book ANABOLIC PHARMACOLOGY at Ergogens - UnderConstruction (http://www.Ergogens.com). [© Seth Roberts, 2009. All rights reserved. For informational purposes only, not to be considered as medical advice or an endorsement of the use of illegal substances.]


1. Saartok T, Dahlberg E, Gustafsson JA: 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. Jun;114(6):2100-6, 1984
2. Pugeat MM, Dunn JF, Nisula BC: Transport of steroid hormones: interaction of 70 drugs with testosterone-binding globulin and corticosteroid-binding globulin in human plasma. J Clin Endocrinol Metab. Jul;53(1):69-75, 1981
3. Aakvaag A, Stromme SB: The effect of mesterolone administration to normal men on the pituitary-testicular function. Acta Endocrinol (Copenh). Oct;77(2):380-6, 1974
4. Schanzer W: Metabolism of anabolic androgenic steroids. Clin Chem. Jul;42(7):1001-20, 1996
5. Jockenhövel F, Vogel E, Reinhardt W, Reinwein D. Effects of various modes of androgen substitution therapy on erythropoiesis. Eur J Med Res. 2(7):293-8, 1997
6. Varma TR, Patel RH. 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. 26(1):121-8, 1988

05-22-2012, 08:05 AM
Proviron is dose dependent as far as effects on LH. Low doses do not reduce already low/normal LH but will lower high levels of LH. At higher doses Proviron shuts down T production so its absolutely suppressive dose dependently.

Methods Find Exp Clin Pharmacol. (http://www.ncbi.nlm.nih.gov/pubmed/6431212#) 1984 Jun;6(6):331-7.

The effects of mesterolone, a male sex hormone in depressed patients (a double blind controlled study).

Itil TM (http://www.ncbi.nlm.nih.gov/pubmed?term=Itil%20TM%5BAuthor%5D&cauthor=true&cauthor_uid=6431212), Michael ST (http://www.ncbi.nlm.nih.gov/pubmed?term=Michael%20ST%5BAuthor%5D&cauthor=true&cauthor_uid=6431212), Shapiro DM (http://www.ncbi.nlm.nih.gov/pubmed?term=Shapiro%20DM%5BAuthor%5D&cauthor=true&cauthor_uid=6431212), Itil KZ (http://www.ncbi.nlm.nih.gov/pubmed?term=Itil%20KZ%5BAuthor%5D&cauthor=true&cauthor_uid=6431212).

Based on computer EEG (CEEG) profiles, in high doses, antidepressant properties of mesterolone, a synthetic androgen, were predicted. In a double-blind placebo controlled study, the clinical effects of 300-450 mg daily mesterolone were investigated in 52 relatively young (age range 26-53 years, mean 42.7 years) male depressed outpatients. During 6 weeks of mesterolone treatment, there was a significant improvement of depressive symptomatology. However, since an improvement was also established during the placebo treatment, no statistically appreciable difference in the therapeutic effects of mesterolone was established compared to placebo. Mesterolone treatment significantly decreased both plasma testosterone and protein bound testosterone levels. Patients with high testosterone levels prior to treatment seem to have had more benefit from mesterolone treatment than patients with low testosterone levels. The degree of improvement weakly correlated to the decrease of testosterone levels during mesterolone treatment.

PMID:6431212 [PubMed - indexed for MEDLINE]

11-04-2018, 02:36 PM
Provo Ron was highly useful when there were no ai's because the way it inhibits gyno is like an ai. It will also give hardness to an alreaean physiwue. 50 mgs a day is enough. Personally I think it's worthless. Everything that proviron does another drug out there can do better.