Nandrolone (NPP) is well known for being one of the best off-season bulking agents for steroid users. The primary functions of NPP include but are not limited to the following: Enhanced protein synthesis, inhibiting glucocorticoid hormones, promotes enhanced IGF-1 production, increases nitrogen retention, increases red blood cell count, increase collagen synthesis and enhances bone mineral content. The recovery factor this promotes is truly tremendous and is one of the reasons and often the only reason some athletes use the steroid.