I was on Femura/Letrozole for 6 weeks and had all the symptoms your described for Arimidex. Horrible. My oncologist told me to take a break for 2 weeks, which I did. I am now on Aromosin for 3 weeks and the jury is still out. Have some aches, but I think the worse kicks in about 5-6 weeks. I would love to try Tomoxifen but my Oncologist wanted me to try Aromosin first.