Glycine
The smallest amino acid: sleep trials, collagen math and the GlyNAC studies, with critiques.
Education only, not medical advice.

Glycine
Glycine and sleep
3 g before bed improved subjective sleep in small Japanese trials funded in part by a glycine maker.
4 min · 3 sources · Grade C
Glycine and collagen
Glycine is a third of collagen. One analysis argues the body may not make enough; this is a hypothesis.
3 min · 1 sources · Grade D
GlyNAC: the Kumar and Sekhar trials, with critiques
Glycine plus NAC raised glutathione in small trials from one lab. Interesting, unreplicated.
6 min · 3 sources · Grade D