My fav is Arimidex. I use 1/4 tab QOD and have results i.e loosing estrogen weight asap. Only problem is they are expensive if you can get the right brand product.It is potent since binds aromotase irrevrsibly. I use it anytime when estrogen rise during the cycle. Post cycle i prefer Clomid since FSH & LH are raised with a different MOA rather lowering Estrogen.