Personally, and this is only me, I use it e3d or eod if I'm running higher than normal test. Depends on your body and how sensitive you are to the compounds that you are running. Luckily I don't have a lot of problems with gyno and aromatization, but I know a lot of guys that do. I have a friend who gets gyno really bad if he looks at a bottle of test and doesn't take it eod. There are others here who may disagree but that's what works for me. I just watch how I feel and keep an eye on my bloods.