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. Its effectiveness at the androgen receptor of muscle tissue is superior to that of testosterone: it binds better. Yet, it gives only about half the muscle-building results per milligram. This I think is a result of its being less effective or entirely ineffective in non-AR-mediated mechanisms for muscle growth.
It also appears less effective or entirely ineffective in activity on nerve cells, certainly on the nerve cells responsible for erectile function. Use of Deca as the sole AAS often results in complete inability to perform sexually. These problems can be solved by...