Proviron contains mesterolone, a synthetic androgen derived structurally from dihydrotestosterone. It is orally active and binds to androgen receptors, producing androgenic effects.

Mesterolone has been used in some countries for conditions associated with androgen deficiency and certain male reproductive disorders. Unlike testosterone, mesterolone does not undergo aromatization to estrogen.

The supplied product identifies a 25mg tablet strength. As with other androgenic medicines, clinical use requires consideration of hormonal status, prostate health, fertility, cardiovascular factors, and other individual risks