Its going to be different for everyone. Remember that we dont want to just wipe estreogen out totally. You want to have some to maintain normal health. We all react differently to different AI's. Personally, I like to stick with Adex, espiecally for a newer user. It can be more forgiving than letro, which is very strong and can wipe estrogen away quickly, leaving you with other issues of low E. Arom is good but it also can be hard to take enough when someone is prone to estrogen issues. I find that for some guys, if they miss a dose, pre-gyno signs pop up quickly when they forget a dose. So until you learn more about how your body responds, stick with arimiex. Then later when you are more confident, you could try arom. It will be easier on cholesterol and I would save the letro for precontest, when you dont mind tanking estrogen, if you want lower E for the last few weeks.