I was on Letrozole for 9 months before chemo. The only side effect I had was hot flashes. My neuropathy is chemo induced and improved somewhat after chemo finished. I'm off Letrozole in two months and looking forward to some (hopefully) real improvements in the next year. I'm also transitioning off Prolia which I think may be sharing the blame for a lot of my joint issues. I'm blaming Letrozole (or any AI, I've been on all 3) for insomnia, brain fog, elevated lipid levels, moodiness, inability to lose weight, and probably more. But after the initial improvement of my neuropathy after finishing chemo (about a year), my neuropathy has worsened only slightly in the last year. (I finished chemo 4 years ago).