Nandrolone phenylpropionate is an injectable form of the anabolic steroid nandrolone. The properties of this drug are strikingly similar to those of Deca-Durabolin®, which uses the slower acting drug nandrolone decanoate. The primary difference between these two preparations is the speed in which nandrolone is released into the blood. While nandrolone decanoate provides a release of nandrolone from the area of injection lasting approximately 3 weeks, nandrolone phenylpropionate is active for only about a week. In clinical situations, Deca-Durabolin can thus be injected once every 2 or 3 weeks, while Durabolin® is usually administered every several days to once weekly. Otherwise, the two drugs are virtually interchangeable. Like Deca Durabolin, Durabolin is valued by athletes and bodybuilders for its abilities to promote strength and lean muscle mass gains without significant estrogenic or androgenic side effects.

Structural Characteristics:

Nandrolone phenylpropionate is a modified form of nandrolone, where a carboxylic acid ester (propionic phenyl ester) has been attached to the 17-beta hydroxyl group. Esterified steroids are less polar than free steroids, and are absorbed more slowly from the area of injection. Once in the bloodstream, the ester is removed to yield free (active) nandrolone. Esterified steroids are designed to prolong the window of therapeutic effect following administration, allowing for a less frequent injection schedule compared to injections of free (unesterified) steroid. Nandrolone phenylpropionate provides a sharp spike in nandrolone release 24-48 hours following deep intramuscular injection, and declines to near baseline levels within a week.

Administration (Men):

The usual dosage for physique- or performance-enhancing purposes is in the range of 200-400 mg per week, taken in cycles 8 to 12 weeks in length. This level is sufficient for most users to notice measurable gains in lean muscle mass and strength. Note that due to the fastacting nature of the phenylpropionate ester, the weekly dosage is usually subdivided into 2 separate applications spaced evenly apart.

Administration (Women):

For physique- or performance-enhancing purposes, a dosage of 50 mg per week (given in a single weekly injection) is most common, taken for cycle lasting 4 to 6 weeks. Higher doses or longer durations of use are discouraged due to potential for androgenic side effects. Although only slightly androgenic, women are occasionally confronted with virilization symptoms when taking this compound. Should virilizing side effects become a concern, nandrolone phenylpropionate should be discontinued immediately to help prevent a permanent appearance.