Primobol is a mild anabolic with extremely low androgenic activity, meaning that there is only a minimal chance of typical steroid side-effects. It does not convert to estrogen and, therefore, estrogen-caused water retention and fat deposition will not occur from using it. Methenolone increases the conversion of protein to lean muscle tissue through its anabolic activity. Because methenolone has virtually no androgen (i.e., masculinizing) effects, it can generally be used safely by women.