NAC is a great supplement. It's awesome stuff to support healthy lungs. NAC is a known mucolytic. That is a fancy term meaning breaking up mucus. Now, research does show that NAC Frontiers Glutathione: A Samsonian life sustaining small molecule that protects against oxidative stress, ageing and damaging inflammation Levels of Reduced Glutathione (GSH) in Plasma and Lungs of Control and Download Table Glutathione: The Master Antioxidant Core Med Science Lung glutathione and oxidative stress: implications in cigarette smoke induced airway disease American Journal of Physiology Lung Cellular and Molecular Physiology American Physiological Society