@AllyJay Your theory makes lots of sense to me. It sounds logical and I can only hope it's true! It's exactly three months today since I started Letrozole, and I've got progressively worse. This last two weeks have seen the aches spread, the mood worsen and the fatigue increase. I'd love a plateau to settle into! I hope it settles down soon. Experience tells me I'll get used to a lot of it but I need it to be stable to relegate it to a background murmur rather than a foreground chatter... Still can't get my head around the fact that my ankles are going to badly ache 24 hours a day for at least five years...