@kazani: Glycine's role in sleep, glutathione, and aging

Glycine, the simplest amino acid, is described as a foundational molecule whose "non-essential" classification may be scientifically incomplete. Research cited suggests that 3 grams taken before bed may activate receptors in the brain's master clock, linked to peripheral vasodilation and a drop in core body temperature that supports sleep onset. Glycine is described as the rate-limiting amino acid for glutathione, one of the body's key intracellular antioxidants, and supplementing it with NAC has been associated with improvements in multiple hallmarks of aging. Research also suggests glycine may enhance exercise performance, reduce lactic acid accumulation, and support muscle recovery.