sustanon is a mixture of 4 testosterone variations. test propionate, test phynolpropionate, test isocaproate, and test decanoate. the first two are fast acting, the 2nd two are longer lasting. IMO it should be shot EOD to take advantage of the short esters, and being that it hurts like hell I stay away from it. test enanthate and cypionate that you mentioned are each single compounds and are far easier to cycle with.