I was on letrozole and had low energy levels enough to need a sleep every afternoon, painful knees and fingers as well as low moods. Doctor wouldn't change it for 3 months to give it time to settle, it then took another 5 weeks for the new prescription to arrive at my gp. I've been on exemestane for 6 weeks now and have my energy back, think nothing of a mile walk and a lot brighter in myself. So if letrozole doesn't suit persevere in getting one that does.
