Mesterolone is a dihydrotestosterone derivative taken by mouth: an androgen with only weak anabolic character, which is why its medical history lies in androgen deficiency rather than tissue building. Unlike testosterone, it is not a substrate for aromatase.
Alpha Pharma's version is Provibol, fifty 25 mg tablets to the pack, the strength the molecule has carried since first registration. It does not rely on the 17-alpha-alkylation that burdens many oral compounds; a 1-methyl group handles oral survival instead.
