There is no natural alternative to letrozole. The main side effects is arthritis type pain in smaller joints. But once up and moving mine go away, sonetimes needing panadol. Vaginal dryness I manage with replens . But there is a natural product called yes. Some people swear by fish oil capsules...perhaps just increase the fish naturally. I guess you won't know until you start but I have been pleased so far on the medication as was expecting lots if issues like I had with chemo.