Hi, I am on LDN and actually increased to 9mg because I have long COVID and my Epstein Barr Virus was triggered. My doctor slowly increased my dosage to 9mg because he said 9mg has been helping patients with inflammation. I split my dosage in half and take one in the am and one in the pm. It does not cause my headaches. Have you ever tried hydrogen peroxide spray to help with sinus and allergies ? It works great for my husband and I. It is over the counter. My local heath store carries it but I know Amazon has it too. I will attach a picture of it. It is natural product. Hope this helps.