In the body, NAC (N-Acetyl Cysteine) converts to L-cysteine, a nonessential amino acid. The body then uses L-cysteine to make glutathione, which is a tripeptide or chain of amino acid cysteine, glycine, and glutamic acid.Glutathione is an antioxidant with important functions in the body, such as protective effects towards DNA damage & carcinogenesis, supporting the immune system, supporting the function of specific enzymes, helping certain organ functions, and more.Increasing L-cysteine will increase the rate of the supply of glutathione production in the body. NAC is more soluble than L-cysteine itself, which is why NAC is often used in supplements instead of L-cysteine by itself.NAC increases exercise performance and reduces oxidative stress, especially in those low in glutathione. Studies have also indicated that NAC may help reduce the mucus build-up and inflammation of the lungs and bronchial tubes by way of glutathione.