I did make a mistake in my previous post because Glycine is not chiral, it has no L- or R-. so it is not L-Glycine it's simply Glycine. It's a very simple ammino acid.
I have Chronic-Fatigue-Syndrome so anything which shifts things towards relaxation/sleep is not required. I am constantly rebalancing my nervous system because of all the parasympathetic nervous stimulation that is generated.
Glycine is very beneficial and is one of the most widely used amino acids by the body. It makes up a significant portion of collagen which is the reason why I purchased it because of a scar that I wanted to reduce. One of the best sources and cheapest is Bone broth soup but it is present in many foods, animal protein in particular. It is recommended for chronic fatigue but it did not benefit me.