I too deal with brain fog. Typically after an "event" it is the worst. I use cerefolin nac (Dr Grubb recommended) - also use l-methlyfolate, methylcobalamin, and n-acetyl-cysteine (as substitue for cerefolin nac) because the rx is very expensive and my insurance doesn't cover. Thought earlier this year I was coming down with RA - every joint hurt so bad in the morning. Felt like crumpled spider getting out of bed in the morning. Had a friend recommend removing gluten from my diet and i feel SO MUCH BETTER! Helps with the brain fog too. Hope this helps and best wishes.