I don't deal with CFS but Fibro and advancing OA issues, hip replacement damage so OA is a lot worse after this surgery. A friend who deals with CFS put me on the Potassium and it's possible deficiency in our bodies...The RDA for adults is 4700mg+ daily. We don't get near that much with foods... She takes 200mg potassium gluconate 3-4 times daily and the best foods with potassium, this helps the ME she deals with. I take extra potassium daily and realized this morning I was more fatigued when I woke up, didn't take the 200mg I often take at bedtime....So I believe I hit on something here... I've had labs done and always come in at lower end of range. So....this could be a big key to more energy for so many. Do your research of course.