NAC [N AcetylCysteine] is a precursor of Glutathione. PICTURE: Glutathione is made from three amino acids and cysteine is one of them 87 studies. 9,000+ children. and most parents have never heard this conversation. A meta analysis of 87 studies involving over 9,000 children found consistently lower glutathione levels and higher oxidative stress in children Glutathione Metabolism in Renal Cell Carcinoma Progression and Implications for Therapies Amazon.com: Klaire Labs SFI Health N Acetyl L Cysteine 500mg Amino Acid Glutathione Precursor NAC Supplement to Support Cellular Antioxidant Protection Hypoallergenic, Soy Free, Corn Free (90 Capsules) : Health & Household