For some reason, Eq is usually compared with Deca and the only real comparison is that gains with the two are very similar, with perhaps the edge in strength going to Eq, and the edge in weight gain going to Deca Durabolin. In terms of actual action in the body, Eq doesn’t act much like Deca. In fact, Deca is a progestin and a 19-nor derived steroid whereas Eq is much more closely related to testosterone (being only one double bond different).
EQ was created as an attempt to produce an injectable version of Dbol. To do this, scientists simply added an ester (the very slow releasing Undeclynate ester) to the same steran nucleus they created out of testosterone to create Dianabol. This means they simply added a double bond between carbon atoms 1 and 2, and in this case, estrified it. This 1-2 double bond dramatically slows the rate of conversion to estrogen.
Because of that simple modification it is only going to convert to estrogen (aromatize) at about half the rate of Testosterone.
Still, a lot of test aromatization all together. I think arimidex is a good idea personally.