Meno Clinic NAC (N Acetyl L Cysteine): Building Blocks for Glutathione Meno Clinic N acetylcysteine (NAC) is an important medication used in the management of acute liver failure, especially when it is caused by paracetamol (acetaminophen) overdose. NAC works by replenishing glutathione, a vital antioxidant in Did you know NAC helps your body make glutathione aka your body's strongest antioxidant? That means: Detox support Reduced oxidative stress Immune boost Brain + mood support NAC vs. Glutathione and How They Work Invigor Medical