Nandrolone phenylpropionate, often abbreviated as NPP, is an esterified form of nandrolone. Its phenylpropionate ester provides a shorter release profile than nandrolone decanoate.

The compound belongs to the anabolic-androgenic steroid family and can influence androgen-responsive tissues and reproductive hormone signaling. Potential effects include suppression of endogenous testosterone production, reduced fertility, lipid changes, and cardiovascular concerns.