Trade Names: Proviron

Chemical Names: Mesterolon

Routes: Oral

Half-life: 12 hours

Proviron was developed by Schering in 1934, making it one of the first drugs used in hormone replacement therapy. Mesterolone is very similar to dihydrotestosterone in that it is a strong androgen but a very weak anabolic agent.

When used on its own Proviron doesn't lead to large muscle gains. Where it does play a significant role, is that it binds as much as 60-65% to the Sex- Hormone Binding Globulin (SHBG). This may act to displace other steroids more weakly bound to SHBG into a free (active) state. SHBG binds to testosterone very strongly and about 95-99% of your testosterone is connected to it. Only the free fraction of circulating testosterone is actually what is making you grow. In simpler terms, Proviron’s ability to connect so strongly to SHBG will free up other steroids in your stack to allow them to exercise more activity. Proviron also binds to the aromatase enzymes, preventing them from converting your other steroid compounds to estrogen. This gives Proviron the added benefit of acting as a moderately effective anti-estrogen. Thanks to this, Proviron has no estrogenic side-effects making it a very welcome addition to any pre-contest cycle.

Another advantage is that Proviron is not c-17 alpha alkylated. Instead it was modified with the addition of a methyl group at carbon one, which helps protect the hormone from hepatic metabolism during oral administration. This is a characteristic shared with oral Primobolan. Since it’s not c-17 alpha alkylated liver toxicity is non-existent and thus Proviron is considered one of the safest steroids out there together with Primobolan. Androgenic side-effects like oily skin, acne, facial/body hair growth and male pattern boldness are still very common. Woman should avoid this drug due to its virilising side-effects. Suppression of testosterone is minimal compared to some others. Low dosages of 20 to 25mg can thus be used during PCT without affecting your PCT in any negative way. Normal dosages can range from 20mg up to 100mg per day. Some use it in the 150 to 200mg per day dosage range. It is a very safe drug and even at those dosages, has very little detrimental effect. Beyond the 100mg per day dosage, you start going into the zone of diminished returns. I personally have found the most effective dose to be between 50-100mg per day. Proviron is readily available and moderately priced. Proviron is definitely a drug that can be used in any stack and even beginners can add it to their cycles to aid results without increasing the dosage of other steroids.