Proviron (mesterolone) by Jintani Labs

Proviron (mesterolone) is oral androgen mesterolone (1-methyl dihydrotestosterone). Similar to dihydrotestosterone, mesterolone is a strong androgen with only a weak level of anabolic 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.

Mesterolone is a modified form of dihydrotestosterone. It differs by the addition of a methyl group at carbon, 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/1o This may act to displace other steroids more weakly bound to SHBG into a free (active) state.

Mesterolone is not aromatized by the body, and is not measurably estrogenic. An anti-estrogen is not necessary when using this steroid, as the drug is unlikely to induce gynecomastia, water retention, or other estrogen-related side effects. Mesterolone is actually believed to act as an antiaromatase in the body, preventing or slowing the conversion of steroids into estrogen.

The result is somewhat comparable to Arimidex, although less profound. The anti-estrogenic properties of mesterolone are not unique, and a number of other steroids have demonstrated similar activity. Dihydrotestosterone and Masteron (2-methyl-dihydrotestosterone), for example, have been successfully used as therapies for gynecomastia and breast cancer due to their strong androgenic and potentially anti-estrogenic effect. It has also been suggested that nandrolone may even lower aromatase activity in peripheral tissues where it is more resistant to estrogen conversion (the most active site of nandrolone aromatization seems to be the liver).The antiestrogenic effect of all of these compounds is presumably caused by their ability to compete with other substrates for binding to the aromatase enzyme. With the aromatase enzyme bound to the steroid, yet being unable to alter it, an inhibiting effect is achieved as it is temporarily blocked from interacting with other hormones.

Mesterolone is classified as an androgenic steroid. Androgenic side effects are common with this substance, especially with higher doses. This may include bouts of oily skin, acne, and body/facial hair growth. Anabolic/androgenic steroids may also aggravate male pattern hair loss. Women are also warned of the potential virilizing effects of anabolic steroids. These may include a deepening of the voice, menstrual irregularities, changes in skin texture, facial hair growth, and clitoral enlargement. Additionally, the 5-alpha reductase enzyme does not metabolize mesterolone, so its relative androgenicity is not affected by finasteride.

Mesterolone is not c17-alpha alkylated, and not known to produce hepatotoxic effects; liver toxicity is unlikely.

Anabolic/androgenic steroids can have deleterious effects on serum cholesterol. This includes a tendency to reduce HDL (good) cholesterol values and increase LDL (bad) cholesterol values, which may shift the HDL to LDL balance in a direction that favors greater risk of arteriosclerosis. The relative impact of an anabolic/androgenic steroid on serum lipids is dependant on the dose, route of administration (oral vs. injectable), type of steroid (aromatizable or non-aromatizable), and level of resistance to hepatic metabolism. Mesterolone is an oral non-aromatizable androgen,and expected to have a notable negative effect on lipids. Studies administering 100 mg of mesterolone per day to hypogonadal men for approximately 6 months demonstrated a significant increase in total cholesterol (18.80/0) and LDL cholesterol (65.20/0), accompanied by a significant decrease in HDL cholesterol (-35.7°;6).

Mesterolone should not be used when cardiovascular risk factors preclude the use of other oral steroids. To help reduce cardiovascular strain it is advised to maintain an active cardiovascular exercise program and minimize the intake of saturated fats, cholesterol, and simple carbohydrates at all times during active anabolic steroids administration. Supplementing with fish oils (4 grams per day) and a natural cholesterol/antioxidant formula such as Lipid Stabil or a product with comparable ingredients is also recommended.

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.

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.

Proviron (mesterolone)

Proviron is an oral DHT steroid compound similar to Masteron. Although it is not an ideal compound for building muscle (actually it is not good at all for this purpose), Proviron is helpful in stacks because of its unique ability to keep the body from turning testosterone into estrogen, thus giving the testosterone a better anabolic effect. This aids the bodybuilder in many ways. First, it helps reduce estrogenic side effects of other steroids water-retention, lowered sex drive, gynocomastia, etc. Also, Proviron can help boost the potency of testosterone in the body by freeing testosterone from its binding to sex hormone-binding globulin.

Proviron is therefore best stacked with testosterone, which makes taking anti-estrogen compounds unnecessary. However, Proviron can cause high blood pressure so blood pressure medication may be required for those prone to hypertension.

Proviron is the Schering brand name for the oral androgen mesterolone (1 methyl-dihydrotestosterone). Just as with DHT, the activity of this steroid is that of a strong androgen which does not aromatize into estrogen. In clinical situations Proviron is generally used to treat various types of sexual dysfunction, which often result from a low endogenous testosterone level. It can usually reverse problems of sexual disinterest and impotency, and is sometimes used to increase the sperm count. Proviron does not stimulate the body to produce testosterone, but is simply an oral androgen substitute that is used to compensate for a lack of the natural male androgen.

Although Proviron is strongly androgenic, the anabolic effect of it is considered too weak for muscle building purposes. This is due to the fact that Proviron is rapidly reduced to inactive metabolites in muscle tissue, a trait also characteristic of dihydrotestosterone. The belief that the weak anabolic nature of this compound indicated 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 sex hormone-binding globulin, Proviron may actually work to increase the activity of other steroids by displacing a higher percentage into a free, unbound state. Among athletes Proviron is primarily used as an anti-estrogen. It is believed to act as an anti-aromatase in the body, preventing or slowing the conversion of steroids into estrogen. The result is somewhat comparable to Arimidex (though less profound), the drug acting to prevent the buildup of estrogen in the body. This is in direct contrast to Nolvadex, which only blocks the ability of estrogen to bind and activate receptors in certain tissues. The anti-aromatization effect is preferred, as it is a more direct and efficient means of dealing with the problem of estrogenic side effects. Another disadvantage of Nolvadex is that if discontinued too early, a rebound effect may occur as high serum estrogen levels are again free to take action. This of course could mean a rapid onset of side effects such as gynecomastia. Most actually prefer to use both Proviron and Nolvadex, especially during strongly estrogenic cycles. With each item attacking estrogen at a different angle, side effects are often greatly reduced.

The anti-estrogenic properties of Proviron are not unique to this compound. A number of steroids have in fact demonstrated similar activity. Dihydrotestosterone and Masteron (2methyl-dihydrotestosterone) for example have been successfully used as therapies for gynecomastia and breast cancer due to their strong anti-estrogenic effect. It has been suggested that nandrolone may even lower aromatase activity in peripheral tissues where it is more resistant to estrogen conversion (the most active site of nandrolone aromatization seems to be the liver). The anti-estrogenic effect of all of these compounds is presumably caused by their ability to compete with other substrates for binding to the aromatase enzyme. With the aromatase enzyme bound to the steroid, yet being unable to alter it, and inhibiting effect is achieved as it is temporarily blocked from interacting with other hormones.

Proviron is also favored by many during contest preparations, when a lower estrogen/high androgen level is particularly sought after. This is especially beneficial when anabolics like Winstrol, oxandrolone and Primobolan are being used alone, as the androgenic content of these drugs is relatively low. Proviron can supplement a well needed androgen, and bring about an increase in the hardness and density of the muscles. Women in particular find a single 25mg tablet will efficiently shift the androgen/estrogen ratio, and can have a great impact on the physique. Since this is such a strong androgen however, extreme caution should be taken with administration. Higher dosages clearly have the potential to cause virilization symptoms quite readily. For this reason females will rarely take more than one tablet per day, and limit the length of intake to no longer than four or five weeks. One tablet used in conjunction with 10 or 20mg 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).

The typical dosage for men is one to four 25 mg per tablets per day. This is a sufficient amount to prevent gynecomastia, Proviron is often used throughout the entire cycle. As mentioned earlier, it is often combined with Nolvadex (tamoxifen citrate) or Clomid (clomiphene citrate) when heavily estrogenic steroids are being taken (Dianabol, testosterone etc.). Administering 50mg of Proviron and 20mg Nolvadex daily has proven extremely effective in such instances, and it is quite uncommon for higher dosages to be required. And just as we discussed for women, the androgenic nature of this compound is greatly welcome during contest preparation. Here again Proviron should noticeably benefit the hardness and density of the muscle, while at the same time increasing the tendency to burn off a greater amount of body fat. Proviron is usually well tolerated and side effects (men) are rare with dosages under 100 mg per day. Above this, one may develop an excessively high androgen level and encounter some problems. Typical androgenic side effects include oily skin, acne, body/facial hair growth and exacerbation of a male pattern baldness condition, and may occur even with the use of a moderate dosage. With the strong effect DHT has on the reproductive system, androgenic actions may also include an extreme heightening of male libido. And as discussed earlier, Women should be careful around Proviron. It is an androgen, and as such has the potential to produce virilization symptoms quite readily. This includes, of course, a deepening of the voice, menstrual irregularities, changes in skin texture and clitoral enlargement.

Proviron is also not a c17 alpha alkylated compound, an alteration commonly used with oral anabolic steroids. Not using this structure in the case of Proviron removes the notable risk of liver toxicity we normally associate with oral drugs. It is therefore considered a “safe” oral, the user having no need to worry about serious complications with use. This steroid in fact utilizes the same 1-methylation we see present on Primobolan (methenolone), another well tolerated orally active compound. Alkylation at the one position also slows metabolism of the steroid during the first pass, although much less profoundly than 17 alpha alkylation. Likewise Proviron and Primobolan are resistant enough to breakdown to allow therapeutically beneficial blood levels to be achieved, although the overall bioavailability of these compounds is still much lower than methylated oral steroids.

The popularity of Proviron amongst bodybuilders has been increasing in recent years. Many experienced bodybuilders have in fact come to swear by it, incorporating it effectively in most markedly estrogenic cycles. Due to high demand Proviron is now very easy to obtain on the black market. Most versions will be manufactured by Schering, and should cost about $1-$2 per 25 mg tab. This drug is packaged in both push-through strips and small glass vials, so do not let this alarm you. There is currently no need to worry about authenticity with this drug, as no counterfeits are known to exist. If money and availability does not prevent it, Arimidex, Femara, or Aromasin ares actually a much better choice than Proviron though. These drugs were designed specifically as an anti-aromatase, and works much more effectively than anything else we have available.