10ml vial of 300mg/ml Deca (Nandrolone decanoate) Rohm Labs is an injectable steroids and considered the most powerful mass gaining product. It promotes lean muscle mass gains and significant strength without strong androgenic or estrogenic side effects. Deca durabolin can effectively be used in both mass and cutting cycles. It is a form of nandrolone decanoate. This decanoate ester provides slow release of nandrolone for up to 3-4 weeks. It exhibits strong anabolic properties like testosterone. It is used as off-season mass building steroid. It allows the user to achieve their body mass goals easily with impressive results. Deca exhibits significant anabolic effects with minimal androgenic side effects. It is most commonly injected once per week at a dosage of 200-400mg. Thus, with this small amount, estrogen conversion is low and therefore gyno is usually not a problem.