I’ve been on Letrozole for over nine years - after about a year my hair shedding pattern changed (from almost nothing to pretty normal) - other than that I have had no problems with hair at all, and the shedding change is more likely to have been a long term side effect of chemo. I have mostly kept to the new weight I had after chemo ( I lost weight on chemo) but any fluctuations are probably due to changes in exercise patterns (no gym for long slabs because of COVID) or just being careless with carbs, rather than Letrozole. Best wishes.