I just introduced myself in the members forum and realized that a lot of CFS sufferers have not tried sulbutiamine, which for me is the only thing that has worked, and it works WELL. At 800/mg per day, after a couple days loading period, it completely resolves my CFS. And when I stop taking it, about five days later, my symptoms return. I notice a large effect both in my mind as well as physical energy. Interestingly, thiamine and benfotiamine do nothing for me, and sulbutiamine is the only one shown to cross the BBB. Here is a little reading that can help add some extra information: High-dose thiamine improves the symptoms of fibromyalgia. Thiamine and Fatigue in Inflammatory Bowel Diseases: An Open-label Pilot Study. Pharmacologic and therapeutic features of sulbutiamine. Adjuvant role of vitamin B analogue (sulbutiamine) with anti-infective treatment in infection associated asthenia. There is a lot more reading as well on how it affects memory and other benefits, but I think these are the important ones related to CFS.