I was at the end of my rope with sinus issues. I saw my ND who did two things: he had me tested for food allergies using the ELISA method and I took Thorne SF722 for candida overgrowth. I'm almost 100% certain that food allergies were the culprit as about 1.5 weeks into my new "safe food" diet, I no longer had congestion, post-nasal drip, sinus headaches, among other things.
I had actually been to the ER because my headaches had gone on for months, had become non-stop and so painful that I needed medicine stronger than I could get OTC.
I know everybody is different but I came up allergic to wheat, milk, eggs, pineapple (which is in bromelain, commonly used as a natural remedy for allergies), cranberry, kidney bean, brewer's yeast, baker's yeast, chili pepper, and almond. It's amazing what eliminating these foods has done for my health...not to mention my sanity