And for an androgen component, Deca are better choices, including Primobolan. Tablets are typically 25 mg, and taken one or two at a time. Amounts greater than this have no further effect on improving libido off-cycle, but if used for a specific occasion, whether on-cycle or off-cycle, may temporarily improve vascularity, if it is already noticeable but has room for improvement. Mesterolone is the chemical name of active ingredient in Proviron. Mesterolonesold under the brand name Proviron among others, is an androgen and anabolic steroid AAS medication which is used mainly in the treatment of low testosterone levels. Side effects of mesterolone include symptoms of masculinization like acneincreased hair growthvoice changesand increased sexual desire. Mesterolone was first described by  and introduced for medical use by Mesterolone is used in the treatment of androgen deficiency in male hypogonadismanemia Nandrolone, and to support male fertility among other indications. Mesterolone has been used for physique- and performance-enhancing purposes by competitive athletesbodybuildersand powerlifters. Side effects of mesterolone include virilization among others.