Mesterolone Proviron (mesterolone) is basically an orally active DHT (Dihydrotestosterone) preparation. For comparision, we can think of some other orally prepared DHT compounds like Winstrol, Anavar, etc& Those both act very similarly in mechanism to Proviron, but a more accurate way to think of this compound is as something like "Oral Masteron." As I´m sure you noticed, their anabolic/androgenic ratio is very similar.Remember, DHT is 3 to 4 times as androgenic as testosterone and is, of course, incapable of forming estrogen. Also, Proviron is quite unique in that a simple look at it´s 4-ring structure will show us that it is not going to be too liver toxic, since it is not c17-Alpha-Alkylated, as many orals are& this modification (lacking in Proviron) makes drugs more liver toxic.