Hi dmcook, I've been on tamoxifen for 6 months now and find that if I don't exercise I get joint pain, I also get horrific muscle cramps (have always had them to some extent but they have now reached a wonderful new level). I take daily magnesium for the muscle cramps. Sleepwise I used to toss and turn a lot of the night and I've found that my core body temperature seems to have increased (along with the hot flushes) so I don't bother with blankets and just use a sheet to drape over my knees when the temperature drops towards sunrise. My sleep has improved and I don't spend the whole night pulling a cotton blanket on and then throwing it off for 3/4 of the night. I was also getting incredibly forgetful and my oncologist told me about an app for my mobile for brain training. I ended up using the Elevate phone app and that has worked wonders. All in all have found ways around most of the side effects. Hoping for you that you can reduce your joint pain and sleep issues. Xx Cath