Glycine is sold across the wellness internet as a sleep aid, a collagen builder, and an anti aging amino acid for glutathione synthesis. The sleep evidence is real. The other two are mechanism plausible Glutathione prevents chronic oscillating glucose intake induced cell dedifferentiation and failure Cell Death & Disease Glutathione Beyond the Surface Detoxification of methylglyoxal by the glyoxalase system is required for glutathione availability and virulence activation in Listeria monocytogenes PLOS Pathogens Dietary sulfur amino acid restriction improves glucose homeostasis through hepatic de novo serine synthesis bioRxiv