It went away when I dropped the dose down even further (or at least, I think it did. I seem to be pretty close to where I was before). I really didn't like what it was doing to me, so I never waited out the higher dose long enough to know whether the side effects would have faded with time. I can't say for sure whether I'm any worse than I used to be in terms of the overstimulation, but if I am it's subtle now. The lower dose isn't doing anything noticeably bad. ...Though it is a very low dose, so I'm not certain how much good it's doing either. I can't remember where the info originally came from, but I recall acetyl-l-carnitine having a connection to acetylcholine levels (helping to increase production, I believe). I'm willing to bet it shot yours through the roof for some reason. Sounds very much like what you're describing (like the gas pedal on your brain was pushed to the floor). I think it may have done something similar to me. Maybe our natural acetylcholine levels are already quite high? Maybe we just process it differently. It might be worth trying regular l-carnitine (non acetyl), as I believe it might be the acetyl component that's used directly to produce acetylcholine. Maybe we just don't need a boost to that side of things.