Proviron (active ingredient: mesterolone) is a hormonal medication that exhibits moderate androgenic activity and significantly enhances erectile function. It is often used in bodybuilding during anabolic steroid cycles for various purposes.
Among the well-known manufacturers of mesterolone are several branches of Schering (Proviron in 25 mg tablets), Moldovan company Balkan Pharmaceuticals (Provimed, 50 mg tablets), Gerth Pharmaceuticals (Proviger, 50 mg tablets), and a few others.
It acts as a weak aromatase inhibitor, meaning it slightly impedes the conversion of steroids to estrogens in the body. According to numerous athlete reports, in practice, Proviron does not prevent gynecomastia, water retention, fat deposition in a female pattern, and other estrogenic side effects.
Proviron almost does not affect the body's own testosterone production (though it may suppress it in large doses), yet it helps increase the concentration of free testosterone in the blood by inhibiting the activity of sex hormone-binding globulin. These properties make Proviron an attractive addition during a steroid cycle.
It is frequently used as part of post-cycle therapy, although its efficacy is questionable since it does not restore the secretion of endogenous testosterone.
How to Use Proviron During a Cycle
The usual daily dosage for men is 50 mg per day, divided into two equal intakes, preferably after meals. A dosage of up to 100 mg of Proviron per day is considered acceptable. Higher doses may lead to effects opposite to the expected ones. In case of prolonged erection, which is often quite painful and inconvenient, the dosage should be reduced or the intake should be stopped altogether.
Given that the drug enhances libido and improves potency in men, its use is justified in cycles with drugs that lower libido (for example, with the use of nandrolone or trenbolone).
Furthermore, Proviron is often used in bodybuilding for pre-competition preparation to enhance muscle hardness and definition. It is a favorite among Western actors seeking a muscular appearance without resorting to heavier steroid "artillery". Women bodybuilders also use it to give their muscles density, though their dosages should not exceed 25 mg per day for more than four weeks to avoid masculinization, despite professional bodybuilders often exceeding these guidelines.
Medical Uses Proviron
"Improves the quality and increases the quantity of sperm. Compensates for male sex hormone (androgen) production deficiencies, stimulating the development of male genitalia and secondary sexual characteristics, enhances libido and potency, exhibits anabolic properties, stimulates erythropoiesis." Administration method: Orally, without chewing, 25 mg 1–3 times a day.
Some studies suggest Proviron has performed well as an antidepressant. In experiments, mesterolone and amitriptyline both showed good mood improvement results. However, mesterolone was found to be less toxic to the human body, with fewer side effects.
Side Effects
It is not toxic to the liver in moderate dosages, making it safe for use during a course over several weeks. Considering its chemical nature and similarity to dihydrotestosterone, potential side effects include prostate hypertrophy and male pattern baldness.
For prevention, periodic prostate examinations are recommended. Caution in Use: Rarely, the intake of hormonal substances in Proviron has led to the formation of benign, and even more rarely, malignant liver tumors. In some cases, intra-abdominal bleeding caused by such tumors has been life-threatening. If a man using Proviron experiences severe upper abdomen pain, liver enlargement, or signs of intra-abdominal bleeding, the possibility of a liver tumor should be considered in the differential diagnosis.
Interaction with Anabolic Steroids (AS)
Many authors, such as A. Vasilenko and others, point out that the use of Proviron and anabolic steroids (AS) on the same receptors may supposedly reduce the effectiveness of the latter. However, basic pharmacokinetic knowledge debunks this. Firstly, this antiestrogen is rapidly degraded in muscles to inactive metabolites. Secondly, due to its high affinity for binding proteins (SHBG), the drug can increase the concentration of free AS, enhancing the effectiveness of the course.
Choosing Anti-Estrogens
The choice between anti-estrogenic drugs often arises.
Tamoxifen blocks estrogen receptors but does not prevent the formation of estrogens. It is more conducive to the restoration of one's own testosterone because it can directly affect the pituitary gland. Its disadvantage is that it slightly reduces the anabolic activity of steroid drugs. It is used only during PCT.
Proviron increases the concentration of androgens by binding to SHBG, thereby enhancing the effectiveness of the course. However, research has shown that Proviron does not aid in restoring testosterone secretion, unlike tamoxifen. Repeated hormone level analyses have shown that Proviron's anti-estrogenic action during a course is practically non-existent.
Considering the advantages and disadvantages of both drugs, an optimal steroid course is structured as follows (applicable only for aromatizable AS):
Starting from the 2nd week of the course, Proviron is introduced at a dose of 50 mg per day. Additionally, aromatase inhibitors should be used to control estrogen levels.
Immediately after the course ends, Proviron intake is stopped, and after the steroids are eliminated from the body, Tamoxifen is prescribed for 2-3 weeks at a dose of 10-20 mg per day.