NAC: Offering Powerful Free Radical Protection

  • Ameya Juvekar

N-Acetyl-L-Cysteine, more commonly referred to as NAC, is a naturally occurring antioxidant1 that has been growing in popularity in recent years. This compound can be found in allium vegetables, namely onion and garlic. It is a derivative of the dietary amino acid l-cysteine and a precursor to glutathione, one of the most important antioxidants synthesized in the human body.2

Antioxidants are compounds that have the important job of helping fight free radical damage and preventing oxidative stress in the body. Other well-known antioxidants include vitamin C, vitamin E, and astaxanthin. Oxidative stress has been linked to a wide range of diseases and dysfunctions, including cellular damage and cancer3, making the role of antioxidants very important to overall wellness.

Benefits of NAC

In addition to its free radical scavenging abilities, NAC has anti-inflammatory properties.4 Because of these two factors, NAC has been studied as a potential treatment for a wide range of conditions.

Respiratory Health

Most often discussed, NAC has a high affinity for lung tissue. It can relieve symptoms of respiratory conditions by loosening mucus in your air passageways. It has been shown to protect lung tissue in cases of chronic bronchitis, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), and pneumonia.5,6 Oxidative stress and free radicals play a role in COPD, which makes anti-inflammatory substances and antioxidants a logical choice for helping to treat and manage the condition.

Liver and Kidneys

NAC plays an important role in your body’s detoxification process, so it is no surprise that several animal studies suggest that NAC supplementation may also help to moderate the effects of mercury and cadmium accumulation in the kidneys and liver. It may achieve these actions in part by promoting healthy glutathione levels or protecting tissues from peroxidation generated by heavy metals. Additionally, doctors regularly give intravenous NAC to people with an acetaminophen overdose to prevent or reduce kidney and liver damage.7

Insulin Sensitivity

NAC can aid in reducing the risk of insulin sensitivity and metabolic syndrome. In particular, studies have demonstrated that NAC may improve insulin sensitivity in women with polycystic ovary syndrome.7

Cardiovascular Function

Oxidative damage to heart tissue often leads to heart disease, causing strokes, heart attacks, and other serious conditions. NAC may also benefit the heart by reducing oxidative damage.8 A 2012 review found that NAC helped prevent significant cardiovascular illnesses including atherosclerosis, heart failure, and ischemic heart disease, as well as provided benefits prior to various heart surgeries.9


In summary, NAC can help support your body in dampening inflammation, supporting immune system modulation, and improving antioxidant status. All of which influences health on a deep cellular level. NAC provides valuable health benefits to the human body and is available as a stand-alone supplement or as an important ingredient in many supplement formulations.

  1. Antioxidant properties of N‐acetylcysteine: their relevance in relation to chronic obstructive pulmonary disease P.N.R. Dekhuijzen European Respiratory Journal Apr 2004, 23 (4) 629-636; DOI: 10.1183/09031936.04.00016804
  2. Šalamon Š, Kramar B, Marolt TP, Poljšak B, Milisav I. Medical and Dietary Uses of N-Acetylcysteine. Antioxidants (Basel). 2019;8(5):111. Published 2019 Apr 28. doi:10.3390/antiox8050111
  3. Antioxidant properties of N‐acetylcysteine: their relevance in relation to chronic obstructive pulmonary disease P.N.R. Dekhuijzen European Respiratory Journal Apr 2004, 23 (4) 629-636; DOI: 10.1183/09031936.04.00016804
  4. Tardiolo G, Bramanti P, Mazzon E. Overview on the Effects of N-Acetylcysteine in Neurodegenerative Diseases. Molecules. 2018;23(12):3305. Published 2018 Dec 13. doi:10.3390/molecules23123305
  5. Grandjean EM, Berthet P, Ruffmann R, Leuenberger P. Efficacy of oral long-term N-acetylcysteine in chronic bronchopulmonary disease: a meta-analysis of published double-blind, placebo-controlled clinical trials. Clin Ther. 2000;22(2):209-221. doi:10.1016/S0149-2918(00)88479-9
  6. Dekhuijzen PN, van Beurden WJ. The role for N-acetylcysteine in the management of COPD. Int J Chron Obstruct Pulmon Dis. 2006;1(2):99-106. doi:10.2147/copd.2006.1.2.99
  7. Mokhtari V, Afsharian P, Shahhoseini M, Kalantar SM, Moini A. A Review on Various Uses of N-Acetyl Cysteine. Cell J. 2017;19(1):11-17. doi:10.22074/cellj.2016.4872
  8. Liu C, Lu XZ, Shen MZ, et al. N-Acetyl Cysteine improves the diabetic cardiac function: possible role of fibrosis inhibition. BMC Cardiovasc Disord. 2015;15:84. Published 2015 Aug 6. doi:10.1186/s12872-015-0076-3
  9. Talasaz, Khalili, Fahimi & Mojtab. Potential role of N-acetylcysteine in cardiovascular disorders. Therapy (2011) 8(3), 237–245. ISSN 1475-0708.