Used primarily in research and development, particularly in the field of biochemistry and pharmacology, as a stable isotope-labeled compound. It serves as an internal standard in mass spectrometry for accurate quantification of metabolites in biological samples. This compound is also employed in studies investigating the metabolism and pharmacokinetics of related cysteine derivatives, aiding in the understanding of drug mechanisms and detoxification pathways. Its deuterated form enhances precision in analytical methods, making it valuable for tracing and monitoring biochemical processes in both in vitro and in vivo experiments.