Lcysteine is recognized as a conditionally essential amino acid. Under normal physiologic conditions, the body can produce sufficient levels of L-cysteine.
The primary role of Lcysteine is in the production of important antioxidants such as glutathione. Lcysteine serves as precursors for synthesis of proteins, glutathione, taurine and coenzyme A. Pharmaceutical uses include improvement of hepatic function and pigmentation. The acetyl, ethyl ester and carboxymethyl derivatives are used in agents for dissolving air passage mucosa (expectorant).