That's a terrific question, thanks. We need a long term trial with a washout period to spot suspected deficiencies of the tested non essential AA. I've just had a little look and can't see any evidence of this happening but it does make total sense. I suspect that the body will stop producing the AA but perhaps it can get back on track as soon as the supplemented AA is stopped. I wonder how long that would take? I'll see if I can find any more info about it and get back to you if I do.