MSG is a sodium salt of L-glutamic acid (we as humans can not consume other isomeric forms, so L-forms are the only participating in biosynthesis etc.)Hydrochloride of glutamic acid is essentially same salt, just hydrocloride acts as pseudocation. If you take it in, you will have same anion - glutamic acid anion or glutamate, as produces MSG. it is just a matter of where cation or pseudocationis bound to, in hydrocloride it sits on amino group, in monosodium glutamate on one of the OH groups subsituting H.In fact, to be honest, I am staying on the position that MGS threat is one of the 'sity hoaxes', becasue eating cheese or meat or soybean proteins (ANY proteins in fact) daily stuffes you with natural glutamate and all 'artificial' MSG in fact is a NATURAL one, taken from the broth or milk serum etc.here is some basic info about glutamic acid and its properties: . As you see, GA can damage your brain only at ishemic consitions when there is no normal methabolism. Under normal conditions hardly it could be harmful - and therefore adding some extra with the pill hardly can be useful compared to huge amounht you normally consume.So, basically I doubt both severe and irreversible harm casued by MSG in the food (becasue it exsits in every protein containing food in form of glutamic acid) and benefit of putting some small extra amount of refined GA hydrocloride into your belly (cheese is cheaper and tastes nice).