One of the only viable methods of increasing intracellular levels of the superantioxidant glutathione is supplementing with N-acetylcysteine (NAC), a prodrug for the amino acid cysteine.1

Deficiency of intracellular glutathione can worsen oxidative stress and accelerate cellular death in multiple diseases, including Alzheimer disease, Parkinson disease, liver disease, HIV/AIDS, cystic fibrosis, sickle cell anemia, and diabetes.2 Consequently, the potential impact of enhancing this compound in the body is tremendous.


NAC is counted as one of the most important medications needed in a basic health system, according to the World Health Organization (WHO).3 

The WHO indicates NAC is essential for pulmonary and renal protection, antimicrobial uses, and psychiatry.3 NAC has been used as an antidote for acetaminophen toxicity.4 Pulmonologists have also used it as an effective inhaled mucolytic in patients with cystic fibrosis.4


The conversion of NAC to cysteine is the rate-limiting step in the very complex synthesis of glutathione in the human cell.5 Multiple studies both in vitro and in vivo have demonstrated rapid, massive cellular death when an organism is starved of cysteine.5 However, the actual mechanism of cell death appears to be the loss of available glutathione.

NAC has been used with success in respiratory conditions for many years, but the way it works is not clear. Current literature suggests that the main action of NAC is that of a tissue-specific antioxidant. In both cystic fibrosis and chronic obstructive pulmonary disease (COPD), excessive infiltration of pro-inflammatory cytokines and lymphocytes trigger massive up-regulation of potent reactive oxidative species.6 

As the delicate tissues of the pulmonary alveoli are subjected to this toxic stimuli year after year, the body gradually loses its ability to compensate, and lung function declines.

Studies designed to increase intracellular glutathione by means of cysteine supplementation in these respiratory diseases have shown positive results. 

This article originally appeared on Clinical Advisor