Primobolan is the injectable version of the steroid methenolone. It is the same compound as the one in Primobolan Orals (methenolone acetate), both produced by Schering. In this injectable version, an enanthate ester is added to the steroid, which makes for a slow and gradual release from the site of injection. Its length of activity would thus be quite similar to Testosterone enanthate, with blood levels remaining elevated for approximately two weeks. Methenolone itself is a long acting anabolic, with extremely low androgenic properties. It’s anabolic effect is also quite mild, its potency is considered to be slightly less than DecaDurabolin (nandrolone decanoate) on a milligram for milligram basis. For this reason, Primobolan is most commonly used during cutting cycles when a mass increase is not the main goal. Some athletes do prefer to combine a mild anabolic like “Primo” with bulking drugs such as Dianabol, Anadrol, or testosterone however, presumably to lower the overall androgen dosage and minimize uncomfortable side effects. When choosing between Primobolan versions, the injectable is preferred over the oral, as it is much more cost effective.
Since Primobolan does not convert to estrogen, it displays many favorable characteristics. Estrogen related side effects should therefore not be seen at all when using this steroid. Sensitive individuals need not worry about developing gynecomastia, nor should they be noticing any water retention with this drug. The gains seen with Primobolan will be only quality muscle mass, and not the smooth bloat which accompanies most steroids open to aromatization. During a cycle the user should additionally not have much trouble with blood pressure values, as this effect is also related (generally) to estrogen and water retention. At a moderate dosage of 100-200mg weekly, Primobolan should also not interfere with endogenous testosterone levels as much as when taking an injectable nandrolone or testosterone. At higher dosages strong testosterone suppression will be noticed, as all steroids can act to suppress testosterone production at a given dosage. Here of course a proper post cycle therapy is a must.