L-Selenocystine is primarily utilized in biochemical research due to its role as a precursor for the synthesis of selenoproteins, which are crucial for various biological functions. It is often employed in studies investigating the mechanisms of selenium metabolism and its impact on antioxidant defense systems. Additionally, L-Selenocystine is used in the development of therapeutic agents targeting oxidative stress-related diseases, such as cancer and neurodegenerative disorders. Its incorporation into peptides and proteins helps researchers explore the structural and functional effects of selenium in biological molecules. Furthermore, it serves as a valuable tool in nutritional studies to understand the benefits of selenium supplementation in improving cellular health and immune function.