I’m on Tamoxifen and Zoladex and I also get joint pain. My nutritionist recommended that I take 5 milligrams each day of high strength fish oil. I find that if I take that each day and exercise regularly I hardly get any joint pain - in fact I actually feel normal again. Although when I don’t take it regularly my joint pain comes back.
This is what I take:
https://www.bioceuticals.com.au/mobile/preview/UltraClean-85-Liquid/products_b.BioCeuticals