What is Nandrolone Phenylpropionate? Nandrolone Phenylpropionate (NPP) – anabolic steroid that has garnered significant attention and usage within medical and athletic communities. As a variant of the well-known steroid nandrolone, NPP distinguishes itself through its phenylpropionate ester. History and Development The journey of Nandrolone Phenylpropionate began in the 1950s, a period marked by significant advancements