Double strength is the distinguishing feature: Pharmacom fills each of the fifty tablets with 50 mg of mesterolone, where every other entry in this group sits at 25 mg.
The compound is an oral 1-methylated androgen of the dihydrotestosterone family, non-aromatizable and only weakly anabolic; it is grouped with oral steroids on structure rather than on muscle-building potency. Pharmacom appends the strength to the product name as house style, so the 50 in Provironos 50 counts milligrams per tablet, not tablets per pack.