I started Letrozole in Oct 2016, and I have stiff sore ankles, and sometimes knees, and less often, fingers. I am just about to start on anastrozole (arimidex) instead to see if that makes a difference. It is worst early morning, after being in the car for a while, or in the evenings. I was taking paNadal osteo, but switched to fish oil capsules, which give about the same effect. The oncologist said a study had shown when a group of people were switched between letrozole and arimidex, about 50% experienced an improvement in side effects, the other 50% reported no change, so I will give it a try. My cholesterol had increased at last GP appointment, but not sure if it is medication related.
The good news is that both letrozole and anastrozole are available from the FBM (For Benefit Medicines) brand, where profits go back to cancer research. Here is their website
http://www.forbenefitmedicines.com.au