Deca Durabolin is a brand name of Organon Company, the manufacturer of the drug containing the substance nandrolone decanoate. Although nandrolone decanoate is still contained in many generic compounds, almost every athlete connects this substance with Deca Durabolin. Most common are the administrations of 50 mg/ml and 100 mg/ml. Deca Durabolin is the most widespread and most commonly used injectable steroid. Deca’s large popularity can be attributed to its numerous possible applications and, for its mostly positive results. Deca Durabolin causes the muscle cell to store more nitrogen than it releases so that a positive nitrogen balance is achieved. A positive nitrogen balance is synonymous with muscle growth since the muscle cell, in this phase, assimilates (accumulates) a larger amount of protein than usual. The same manufacturer, however, points out on the package insert that a positive nitrogen balance and the protein building effect that accompany it will occur only if enough calories and proteins are supplied. One should know this since, otherwise, satisfying results with Deca cannot be obtained. The highly ana-bolic effect of Deca Durabolin is linked to a moderately androgenic component, so that a good gain in muscle mass and strength is obtained. At the same time, most athletes notice considerable water retention which, no doubt, is not as distinct as that with injectable testosterones but which in high doses can also cause a smooth and watery appearance. Since Deca also stores more water in the connective tissues, it can temporarily help with existing pain in joints. This is especially good for those athletes who complain about pain in the shoulder, elbow, and knee; they can often enjoy painfree workouts during treatment with Deca Durabolin. Athletes use Deca, depending on their needs, for muscle buildup and in preparation for a competition.