Used as a biomarker in clinical diagnostics to assess muscle metabolism and turnover, particularly in studies related to exercise physiology and metabolic disorders. It is also employed in research settings to investigate amino acid transport mechanisms due to its structural similarity to other amino acids. Its presence in biological fluids can indicate altered protein catabolism, making it valuable in monitoring certain genetic or mitochondrial diseases. Additionally, it serves as a reference compound in analytical chemistry for chromatographic and mass spectrometric method development.