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 mucolytic properties and decreases viscosity of lung secretions. NAC has been shown by studies to have a protective effect on the liver and has been used to manage acetaminophen overdose, due to its ability to enhance hepatic and mitochondrial levels of glutathione and by supporting the mitochondrial energy metabolism.