I have I have been on Letrozole now for 7 months. I had muscle & joint pain together with mould nausea initially. After reading up lots on this site and anywhere else I could find anything, I increased my water intake (always carry a water bottle and sip constantly through the day) and slowly built up my exercise regime (walking, cycling & Pilates classes) and these symptoms slowly subsided. Was it just my system getting used to Letrozole, who knows?? At this stage though I don’t have any of these side effects although my blood pressure has now increased somewhat. GP doesn’t believe 5his is linked to Letrozole but I do wonder!
Hope your unwanted side effects settle down quickly.