Nandrolone decanoate is an injectable form of the anabolic steroid nandrolone. The decanoate ester provides a slow release of nandrolone from the site of injection, lasting for up to three weeks. Nandrolone is very similar to testosterone in structure, although it lacks a carbon atom at the 19th position (hence its other name, 19- nortestosterone). Like testosterone, nandrolone exhibits relatively strong anabolic properties. Unlike testosterone, however, its tissue-building activity is accompanied by weak androgenic properties. Much of this has to do with the reduction of nandrolone to a weaker steroid, dihydronandrolone, in the same androgen responsive target tissues that potentate the action of testosterone (by converting it to DHT). The mild properties of nandrolone decanoate have made it one of the most popular injectable steroids worldwide, highly favored by athletes for its ability to promote significant strength and lean muscle mass gains without strong androgenic or estrogenic side effects.
 
Deca Durabolin Recommendations
For these reasons I generally recommend against Deca Durabolin use except where the athlete already knows that he can experience joint relief from the compound, or he wishes to see if that will be the case for him and he understands the possible adverse side effects. I prefer for Deca use to be as low as is effective for any such joint problems, and for the majority of the total steroid dosage to be from other compounds.
The long half-life of the drug results in slow clearance. For this reason, Deca Durabolin is unsuited to short cycles or where drug testing is a possibility. I also consider the drug a poor choice for women due to being at least as virilizing per milligram as most other anabolic steroids except testosterone and taking too long to clear if side-effects occur.