This compound came around early in the wave of commercial steroid development, first being made available as prescription medication in 1962. This steroid is an extremely long acting compound, with the decanoate ester said to provide this drug a slow release time of up to three or four weeks. While perhaps true in a technical sense, what we find with further investigation is that the release paeameters after a single injection are such that strong release of nandrolone is really only maintained for one to two weeks. This figure admittedly fails to take into account drug buildup that may occur after multiple injections, which may allow a longer duration of good effect to be seen.
Nandrolone decanoate its popularity is due to the simple fact that it exhibits many very favorable properties. Structurally nandrolone is very similar to testosterone, although it lacks a carbon atom at the 19th position (hense its other name 19-nortestosterone). The resulting structure is a steroid that exhibits much weaker androgenic properties than testosterone. Of primary interest is the fact that nandrolone will not break down to a down potent metabolite in androgen target tissues. You may remember this is a significant problem with testosterone. Although nandrolone does undergo reduction via the same (5-alpha reductase) enzyme that produces DTH from testosterone, the result in this case is dihydronandrolone. This metabolite is weaker than the parent nandrolone, and is far less likely to cause unwanted androgenic side effects. Strong occurrences of oily skin, acne, body/facial hair growth and hair loss occur very rarely. It is however possible for androgenic activity to become apparent with this as any steroid, but with nandrolone higher than normal doses are usually responsible.
Nandrolone also show an extremely lower tendency for estrogen conversion. For comparison, the rate has been estimated to be only about 20% of that seen with testosterone. This is cause while the liver can convert nandrolone to estradiol, in the other more active sites of steroid aromatization such as adipose tissue nandrolone is far less open to this process. Consequently estrogen related side effects are a much lower concern with this drug.