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 Glutathione system enhancement for cardiac protection: pharmacological options against oxidative stress and ferroptosis Cell Death & Disease Nebulized Glutatione for respiratory health Dr. Kate McLaird ND Disturbances of the Lung Glutathione System in Adult Guinea Pigs Following Neonatal Vitamin C or Cysteine Deficiency Increase in Extracellular Glutathione Peroxidase in Plasma and Lungs of Mice Exposed to Hyperoxia Pediatric Research Full article: Role of glutathione in immunity and inflammation in the lung