I was in a study where they were giving me 10 mg of anastrozole, and it shoved my estrogen way down for a moment but then way up and I started having periods again. Horrible! That scared me and my doctor, so I was taken off anastrozole and they said I should not be on it again. My doc suggested I try another AI, but I was rather terrified by the first go-round with anastrozole; I lost trust. Also, my heart rate went into the 90s when I'm used to it being in the 60s. I feel the systemic effects of AIs were more damaging than helpful. IDK, it's really hard to say what to do. I'm trying so hard to get my cholesterol down, using exercise and fish oil supplements. Also, I don't want my A1C to rise as I'm borderline now. I'm also osteopenic and would have needed Zometa infusions. However, I've needed a fair amount of dental work done, so that would have been a real mess if I had had the infusions. There are so many things that can go wrong using the AIs and only one thing (lowering estrogen) that can possibly go right; even that is a crap shoot. Also, I had debilitating depression, which was awful. So many pieces to the puzzle ...