Proviron is a synthetic androgen (1 methyl-dihydrotestosterone) that lacks anabolic properties but has a "hardening" effect on muscle. Unlike most orals, it is not a 17-alkylated compound. It is also a mild estrogen antagonist. Because it is used primarily for non-building purposes, it is used at relatively low dosages (< 50mg QD). For these reasons it is normally NOT associated with liver toxicity.