I had a lumpectomy in 2007, aged 48, followed by radiotherapy, then 5 years on Tamoxifen with only mild side effects - hot flushes, a few headaches. After 5 years on Tamoxifen by oncologist recommended I change to Femara for 5 years, and I lasted 6 months, but have just made the decision, in conjunction with the Oncologist, to change back to Tamoxifen after a 2 week break, as I couldn't cope with the side effects. First I got joint stiffness, followed by a stress fracture in my foot, which they put down to over-exercising. While I was recovering the aches and pains got worse, and I gained weight, which I put down to not being able to exercise. I slowly started to reintroduce exercise after about 4 months, but broke down again almost immediately, this time with my knee. An MRI has revealed another stress fracture, this time in the top of the tibia where it weight bears the knee. Other side effects are sleeplessness at night, aching in every joint (I hobble out of bed in the morning like a 90 year old) and can hardly bend my fingers sometimes, also very emotional. Both my GP and the Oncologist seem to think Femara is the cause, so we will see how I go whilst back on Tamoxifen in a couple of weeks.