The mechanism of action of N acetylcysteine (NAC): The emerging role of H2S and sulfane sulfur species ScienceDirect 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 TYLENOL [Acetaminophen] metabolism A lot of GLUTATHIONE is needed to deal with the Oxidative Stress generated by the CYP 450 metabolism of Tylenol. When people go to the ER for Tylenol Overdose Full article: Dietary Glutamylcysteine: Its Impact on Glutathione Status and Potential Health Outcomes