N-acetyl-cysteine (NAC) is a derivative of cysteine, an amino acid. It has many health benefits, including its ability to promote the replenishment of key antioxidants like glutathione, the most powerful antioxidant in the body.*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease. To get the most out of NAC, you need high-performance supplementation: NP PRO NAC 1200.