This is a supplement that was tested in boys with FX with symptoms of ADHD. There is some info on it here and here. Both of the Drs. we saw at Children’s were in favor of trying this before trying any sort of stimulant medication. They prefer the l-acetyl carnitine vs. l-carnitine which is more widely available.
When you search you’ll see that this is widely used by body builders and the doses they use are higher than were tested. I found a liquid format by MRM (Amazon and Seacoast Vitamins both carry it) that will be easier to give to Monkey since he doesn’t do pills and it will be easier to cut the dosage.