1. Mesterolone is a dihydrotestosterone (DHT) derived anabolic androgen steroid. Specifically it is a structurally altered DHT hormone possessing the addition of a methyl group at the carbon one position. This allows the hormone to survive oral ingestion by protecting it from hepatic breakdown. 

 2. This is one of the only oral anabolic steroids that is not C17-alpha alkylated (C17-aa) but instead carries the added methyl group. Oral Primobolan is the other most well-known Oral steroiddthat carries this same methyl group.

 3. While the added methyl group does in fact protect it from breakdown, the total bioavailability of Proviron will be far less than most all C17-aa oral steroids. For this reason it has fallen out of popularity among many performance enhancing athletes but as we will see perhaps unjustifiably so.

 4. Proviron carries an androgenic rating of 30-40 and an anabolic rating of 100-150. All ratings derive from and are measured againsteestrogen,which carries a rating of 100 in both categories. Despite having an anabolic rating that is potentially greater than testosterone, 

 5. Proviron will display very low anabolic traits. This is very similar to Halotestin (Fluoxymesterone), which carries a massive anabolic rating but very little translatable anabolic activity.

 6. In the case of Proviron, while structurally very anabolic, the Mesterolone hormone converts and reduces to Diol metabolites, in turn reducing anabolic activity. However, 

 7. Proviron’s androgenic rating is a different story. In fact, its translatable androgenic activity appears to commonly be higher than its structural rating would imply.

 8. On a functional basis, Proviron carries four primary traits that largely define its mode of action. First and foremost the Mesterolone hormone has a strong binding affinity to Sex-Hormone-Binding-Globulin (SHBG). In fact, it appears to be one of the strongest anabolic steroids in this regard. 

 9. By binding to SHBG, a hormone partially responsible for reducing free testosterone, binding SHBG will enhance the amount of circulating free testosterone. 

 10. More importantly for the anabolic steroid user, it will make a larger percentage of the anabolic steroids used available in a free rather than bound state. A simple way to look at it is the anabolic steroids you’re taking become more powerful and potent.

 11. Proviron also has the ability to interact with the aromatase enzyme, the enzyme responsible for the conversion of testosterone to estrogen. 

 12. By binding to the aromatase enzyme, Proviron can actually inhibit aromatase activity, thereby offering protection against estrogenic side effects. It will not carry an anti-estrogenic effect near the level of power of an Aromatase Inhibitor (AI) but it will be notable.

 13. Depending on the nature of the cycle the individual undertakes it is quite possible for Proviron to take care of all your anti-estrogen needs.

 14. The Mesterolone hormone will also carry a strong binding affinity to the androgen receptor. Once again this will promote the functionality of other steroids to a degree but more importantly promote enhanced metabolic activity through direct lipolysis. 

 15. Then we’re left with the final issue that surrounds Proviron as a fertility medication. This is an anabolic steroid that does not suppress gonadotropins similarly to other anabolic steroids. 

 16. With minimal suppression and its extremely strong androgenicity, this will enhance sperm production as androgens are necessary to spermatogenesis stimulation. This not only enhances the amount of sperm produced but greatly and equally important enhances the quality of the sperm. 

 17. Before we go any further understand Proviron does have the ability to suppress gonadotropins, but there’s a line that has to be crossed for notable suppression to interfere with sperm production. This will make sense once we dive into the side effects section