Clinicians giving several grams a day of pure L-Glutamine do not report excitotoxic reactions. The main one is for the synthetic chemical MSG. Sometimes people react to fermented foods, which indicates a problem in containment and nutritional status. Vitamin C removes glutamate from the neurons, which are additionally protected by antioxidants (tocotrienols, tocopherols, et al) and by magnesium. Branched-chain amino acids help to compartmentalize glutamates. Glutamine is fine with other aminos; the main competition is between the arginine pathway aminos (arginine, ornithine, and lysine); with another noted competition to get through the Blood Brain Barrier between the Large Neutral Amino Acids: aromatic aminos (tyrosine, phenylalanine, and tryptophan) and the BCAAs (leucine, isoleucine, and valine).