Nandrolone Phenylpropionate (NPP) is a version of nandrolon that is not as popular. Before we go any further, you should know the difference between NPP and Deca, which is just the ester. Both are a version of nandrolon, but the ester in Deca is longer than the one in NPP. A lot of people don’t realize that they can take this popular compound via a shorter ester. The only bad thing would be that with a shorter ester you have to take more injections per week, as least one every three days. But with a longer ester it only requires about one or two injections per week.