The unusual properties of Deca Durabolin are due to its parent steroid, nandrolone, also known as 19-nortestosterone. One of the principal positive qualities of nandrolone is that it has relatively low conversion to estrogen compared to testosterone.
In earlier years, testosterone and nandrolone were the only pharmaceutical injectables that were both widely available to bodybuilders and economical. Estrogen control did not then exist. For this reason, Deca’s low aromatizing properties were then quite useful. Deca therefore won wide popularity.
Since deca durabolin is formulated using nandrolone decanoate, one of the longest esters in existence, it is very oil soluble, the way all steroids with long esters are. This easy solubility in oils means that manufacturers have to use a lower percentage of solvents to manufacture the products; thus, making for a less irritating shot. Generally, deca injections are done weekly by most bodybuilders.