I am also on letrozole. I can't deny it has had an impact on my bone density - mine was very good to begin with so I am likely to get through the 5 years my oncologist recommends without anything disastrous. I also have quite severe vaginal dryness. One needs to be monitored, the other to be worked around. No other side effects. I will stick with it because I feel it helps keep any recurrence at bay. There are of course no guarantees but the old refrain - I know I am doing everything I can - is a powerful one. Best wishes with your own choices.