Glutathione metabolic pathways. GCL, glutamate cysteine ligase; GST, Download Scientific Diagram Everyone says NAC can make glutathione. Wrong. Evidence against this is staring right at you. As you can see here, my wife's GCLC gene is genetically slower. Thus, she cannot convert Cysteine Extracellular levels of glutamate, glutamine, cystine, glutathione, and xanthine correlate with transporter expression in tamoxifen resistant MCF 7 cells and poor overall survival in breast cancer patients Cell Biochemistry and Biophysics Glutathione for Food and Health Applications with Emphasis on Extraction, Identification, and Quantification Methods: A Review