Before taking letrozole, tell your doctor or pharmacist if you are allergic to it; or to anastrozole; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems.
To cure the syndrome, they recommend a candida cleanse diet, which includes  no sugar, white flour, yeast and cheese, based on the theory that these foods promote candida overgrowth. Unfortunately, there isn't much evidence to support the diagnosis of yeast syndrome.
Starchy vegetables like potatoes, yams, and beets can feed the yeast overgrowth. While you're healing your gut, I would also avoid legumes like black beans, pinto beans, lentils, peanuts, cashews, and chickpeas. As you heal, you can test these to see how your body handles them.