Nandrolone phenylpropionate (NPP), or nandrolone phenpropionate, sold under the brand name Durabolin among others, is an androgen and anabolic steroid (AAS) medication which has been used primarily in the treatment of breast cancer and osteoporosis in women. It is given by injection into muscle once every week.
NPP is the lesser known and less popular phenylpropionate ester version of nandrolone. First off its important to understand the difference between what we know as ‘deca’ and what we know as “NPP”. To put it in simple terms the difference is simply the ester.