I have injected methylcobalamin 5 milligrams once a week. I haven't tried adenosylcobalamin injections yet but I will try them soon. I am just not sure what the dosage should be. What dosage do you use when you inject adenosylcobalamin? What are the effects? There was a swedish study according to which CFS patients have high level of homocysteine in their cerebral fluid. That would indicate B12-deficiency in the fluid. According to one doctor in Sweden, 10 milligrams once every 4 to 6 weeks would be enough to lower high homocysteine levels in cerebral fluid and my quess is, also in the brain. I think this because one small pilot study showed increased homocysteine levels in the brains of reacently deceased CFS patiens. One 5mg methylcobalamin shot a week seems to help my cognitive symptoms such as ability to concentrate and remember but it doesn't seem to give me more energy. Not atleast yet, after injecting for two weeks. I will try later 5mg in two weeks. Does any of you get more energy from methylcobalamin? What symptoms go away with methylcobalamin injections?