Glycine

Glycine independently promotes better sleep quality, beyond its role in glutathione synthesis. Glycine supports blood sugar regulation by participating in gluconeogenesis and insulin signaling. Glycine promotes sleep quality by acting as an inhibitory neurotransmitter in the central nervous system. Glycine is a background nutrient rather than a fast-acting stimulant. The recommended daily amount of glycine for an average adult is 4–10 grams, with needs increasing with age. The body produces about 3 grams of glycine per day, typical diets supply 1.5–2 grams, but the estimated daily need is about 15 grams, leaving most people roughly 10 grams short each day. Glycine’s effects depend on dose, diet, timing, consistency, and methylation status. Nutrition scientist Dr. Allen Jackson of the University of Southampton has argued that glycine does not belong among the truly non-essential amino acids, implying its official classification understates its biological importance. Glycine is the smallest amino acid and is considered one of the oldest molecules, estimated to date back approximately 3.8 billion years. Glycine is the most accessible precursor amino acid for glutathione synthesis. Gl…