N-Acetyl Cysteine (NAC) is a precursor for the amino acid L-cysteine which when taken orally can cause the body to produce more of the potent antioxidant glutathione that it otherwise would. By raising glutathione levels NAC provides antioxidant effects and similar benefits to taking bioavailable glutathione supplements. In addition to its ability to raise the body’s production of glutathione, NAC also supports healthy liver, lung, and kidney function and may support healthy immune system functioning.