@tygerrag2 have you tried an aromatase inhibitor at all? I know I am not answering your question. I hope though that anyone who needs an AI, based on pathology and Oncotype or Mammaprint, will try different AI's and different manufacturers. It can also be helpful to realize that initial side effects may fade as the body adjusts to the shift in hormones. Many of us did not have significant issues taking them (aside from bone loss, for me, which can be addressed more easily than stage 4 cancer).