S-Sodium ethanethiosulfonate is widely used in organic synthesis as a versatile reagent for introducing thiol groups into various chemical compounds. It is particularly valuable in the preparation of thioethers and sulfides, which are essential intermediates in the production of pharmaceuticals, agrochemicals, and specialty chemicals. Additionally, it serves as a key component in the modification of peptides and proteins, enabling the study of their structure and function. In material science, it is employed to functionalize surfaces and polymers, enhancing their properties for specific applications. Its role as a sulfur donor in chemical reactions also makes it useful in the synthesis of sulfur-containing heterocycles, which are important in drug discovery and development.