Hi... i am new to this board, so please forgive me, as I am just now learning aout all these conditions. I suffered from Chronic Fatigue for years without knowing the root cause. My dr. tested me for the MTHFR mutation and sure enough, I am homozygous (2 copies). Anyway, he told me it was nothing and not even necessary to treat and meanwhile, I went on and on exhausted and miserable for months. Finally, I did my own research on the mutation and found that I should be treating it and that it is absolutely a cause of CFS. Sure enough, I started taking folic acid a few times a day (methylfolate was not in yet, although I ordered it) and I felt great and very energetic within my first few doses. Fast forward, my l-methylfolate 1000 mcgs arrived on Monday, so I stopped taking the folic acid and I was just getting over a cold and BAM, I got a bad sore throat. Ever since I've taken it, every day, the sore throat continues. Is this a coincidence or is it causing my sore throat? it's miserable. The worst part is that it is my only son's birthday party tomorrow and I want to be well, but it doesn't seem in site. For now, i am going to stop taking it and see if I see any improvements. Thank you all so much for listening and for any sharing of your experiences.