I changed from over 2 years on Letrozole to low dose Tamoxifen. I am 68 now and had bone pain, (mostly lower leg and hip) no energy, poor sleep, and dry eye. Have been off Letrozole for about 2 months now and on the low dose Tamoxifen. I feel so much better. ( More like my old self. Even have been getting up early every day!) I am stage !a, T1c, Er Positive, Pr Negative, Her Negative.