Used as a stable isotope-labeled tracer in metabolic studies to track glycine metabolism in biological systems. Enables precise measurement of glycine turnover, protein synthesis, and collagen formation in humans and animals. Commonly applied in clinical research, nutrition studies, and cancer metabolism investigations using mass spectrometry or NMR techniques. Helps distinguish endogenous versus exogenous glycine pools in metabolic pathways such as one-carbon metabolism and glutathione synthesis. Also used in pharmaceutical development for deuterated or labeled drug studies where isotopic purity is critical.