Thanks for that second link. I had read about glycine for sleep, mood, bipolar and schizophrenia (via Glenn Close family study) but not for possible life extension. It does improve my own mood with a dose of several grams per day but the best mental effect seems to be the day I stop taking it. Lower dose does not produce that, it seems to be a dynamic response. So it seems important but complicated, but that's just my anecdote.