N-acetylcysteine (NAC) is a precursor to glutathione synthesis and also acts on its own to reduce the effects of reactive oxygen species.
NAC also has mycolytic properties and decreases the viscosity of pulmonary secretions. Studies have shown that NAC has a protective effect on the liver and has been used to manage acetaminophen overdose, due to its ability to improve hepatic and mitochondrial glutathione levels and support mitochondrial energy metabolism.