Appraising the Role of Astrocytes as Suppliers of Neuronal Glutathione Precursors Immunocal Glutathione Precursor Whey Protein Isolate, Immune Support Sante Medi Glycine and N acetylcysteine (NAC) are amino acidbased nutrients that serve as precursors for glutathione, one of the body's most important intracellular antioxidants. Glutathione plays a central role in reducing oxidative stress, supporting Glutathione Metabolism and Its Implications for Health ScienceDirect