S-Benzyl-L-cysteine is widely used in peptide synthesis as a protecting group for the thiol functionality of cysteine. This helps prevent unwanted side reactions during the formation of peptide bonds, ensuring the integrity of the peptide chain. It is also employed in the preparation of cysteine-containing peptides for pharmaceutical research, particularly in the development of drugs targeting oxidative stress and neurodegenerative diseases. Additionally, it serves as a key intermediate in the synthesis of bioactive molecules and enzyme inhibitors, contributing to advancements in medicinal chemistry. Its role in stabilizing cysteine residues makes it valuable in biochemical studies and protein engineering.