Nandrolone Phenylpropionate is a 19-nortestosterone (19-nor) anabolic androgenic steroid. The 19-nor classification refers to a structural change of the testosterone hormone in that the carbon atom has been removed at the 19^th position. This simple structural change gives us Nandrolone, and by adding the short Phenylpropionate ester we have Nandrolone Phenylpropionate.

On the basis of the hormone’s function, Nandrolone Phenylpropionate is identical to Nandrolone Decanoate. Both forms are comprised of the same active hormone. In the case of NPP we have a shorter ester version that gives a larger burst of Nandrolone after injection, but also carries a much shorter half-life. This means Nandrolone Phenylpropionate has to be injected more frequently than its larger ester counterpart if blood levels are to remain stable.

Nandrolone Phenylpropionate is slightly more anabolic than testosterone with a rating of 125 compared to testosterone’s rating of 100. It is also significantly less androgenic with a rating of 37 compared to testosterone’s rating of 100. The reduced androgenicity is due to the Nandrolone hormone reducing to dihydronandrolone (DHN) instead of dihydrotestosterone (DHT). This is one of the reasons Nandrolone Phenylpropionate can be well tolerated at higher doses in some men than higher doses of testosterone.