Primobol is an injectable steroid made by Balkan Pharmaceuticals. Primobolan is the injectable version of the steroid Methenolone and although it produces a weaker effect than Deca Durabolin it is a very good basic steroid whose effects are predominantly anabolic. The fact that an enanthate ester is added to this steroid enables a slow and gradual release from the injection site. This addition allows for a longer half-life of approx 14 days (similar to Testosterone Enanthate) although most athletes prefer to administer it on a weekly basis.