Decabol is an injectable preparation containing the active ingredient Nandrolone Decanoate. Decabol is used in the treatment of Osteoporosis (ie – bone degeneration) due to its positive influence on calcium metabolism and the increase in bone mass. It also has a positive effect on protein metabolism and is used where a protein deficiency exists, eg. during chronic debilitating diseases, after major surgery & severe trauma. This drug is unique (so far as I know) in that 5a -reductase, the enzyme which converts testosterone to the more-potent DHT, actually converts nandrolone to a less-potent compound. Therefore this AAS is somewhat deactivated in the skin, scalp, and prostate, and these tissues experience an effectively-lower androgen level than the rest of the body. Therefore, for the same amount of activity as another drug at the androgen receptors (ARs) in muscle tissue, Deca gives less activity in the scalp, skin, and prostate. Thus, it is the best choice for those particularly concerned with these things.