Proviron, the brand name for mesterolone, is a synthetic type of male sex hormone. Mesterolone, chemically known as 1-methyl-5?-dihydrotestosterone (DHT), is methylated (the addition of a methyl group –CH3) making it an active steroid very similar to natural DHT that does not convert into estrogen or progesterone (both female hormones) once in the body. Proviron has many positive effects on the body, including increasing muscle mass, enhancing testosterone levels and treating male sexual dysfunction.
Proviron on its own is considered to be a weak steroid according to a study by A.T. Kicman published in the British Journal of Pharmacology. However, it has unique properties that make it a useful and effective enhancer, especially of testosterone. In normal levels in the body, testosterone is mostly inactive because most of it is bound by sex hormone binding globulin (SHBG) and albumin. Proviron also has a great affinity for SHBG, so when administered, it will bind to the SHBG, leaving more testosterone free.
Increase Muscle Density
The increase in free testosterone can then mediate anabolic activities, including protein synthesis, which in turn increases muscle gain.
Estrogen is only active and effective when bound to estrogen receptors. Proviron decreases the ability of these estrogen receptors, found in the muslces, to bind to estrogen, therefore decreasing the amount of active estrogen. In addition, Proviron has an affinity for the aromatase enzyme, which is the enzyme in the body that binds with testosterone and converts it to estrogen. When Proviron binds to the enzyme, it blocks testosterone from binding, therefore reducing the amount of estrogen produced. These effects result in a decrease in water buildup in the body, which gives the muscles a leaner, harder look.
Impotence, also referred to as erectile dysfunction, is the inability to achieve or maintain an erection. One of the causes of impotence is a low level of testosterone. Proviron, as dicussed in the section above, has the ability to enhance testosterone, which can then relieve the symptoms of impotence.
Male infertility, or sub-fertility, is often caused by a problem with the production of sperm. Although the full mechanism of male fertility is not yet understood, it is known that the production of sperm is dependent upon both androgens (like testosterone) and gonadotrophins which are the hormones that stimulate the sexual organs. Androgens have been used to treat infertility problems, but they often decrease gonadotropin secretion, making it ineffective for inducing sperm production.
Proviron stimulates androgens while having little to no effect on the gonadotrophins, according to a study conducted by Patrick Bye and published in the Postgraduate Medical Journal. Proviron, therefore, is a desirable candidate to treat some male infertility and more studies continue to be conducted.