to be extra safe, check estro 1 month into cycle. if its high, start AI and re-check 2wks later. most people will have high estro on cycle whether they feel it or not, but some people react very strongly to ai. for them, the standard .25mg eod of adex may be too much. simply decrease that to e5d or even once a wk. but no matter what, some ai is almost always needed.