As a precursor to make glutathione, NAC has been used for decades both as an acute medication and as an over the counter supplement. Recently, the line between medication and supplement has been NAC N Acetyl Cysteine Super Antioxidant Glutathione Precursor Gene NAC Pure Powder Glutathione & Cellular Health Support* NOW Foods Is It Safe to Take Glutathione and Collagen Together? All About NAC (N acetylcysteine): What it is and what benefits it has Zenement