How Long Does It Take for NAC Supplements to Work? Body Kitchen The Central Nervous System Modulatory Activities of N Acetylcysteine: A Synthesis of Two Decades of Evidence N Acetyl L Cysteine (NAC) glutathione precursor What is NAC? Axon Integrative Health LLC NAC (N acetyl cysteine) is a supplement that supports detoxification, brain health, and lung functionand it's the precursor to the antioxidant glutathione! Key benefits of NAC: Detox Support Helps the liver break