By Chris D. Meletis, N.D.
N-acetyl L-cysteine—NAC for short—is a supplement form of cysteine, a semi-essential amino acid. Supplementing with NAC boosts levels of a powerful antioxidant known as glutathione. NAC is also an antioxidant on itsown.1 This means NAC can fight off excessive oxidative stress, a process that’s damaging to the body when it occurs at high levels.
In addition, NAC supports a healthy inflammatory response. Since the 1970s, it’s also been used for acetaminophen poisoning in the hospital setting thanks to its ability to replenish glutathione in the liver.1,2
Why include a NAC antioxidant supplement as part of your daily routine? Here are seven good reasons:
It’s an Immune System Supplement
A lot of my patients like to take NAC for immunity. Taking NAC supplements on a regular basis is linked to staying healthy in the winter. A randomized, double-blind study, evaluated 262 people primarily at least 65 years old who were given either a placebo or 600 mg of NAC twice per day for six months.3 The participants given NAC spent more time feeling healthy and when they did get sick had less severe symptoms and less down time. Only 25% of the subjects taking NAC developed symptoms compared to 79% in the placebo group.
NAC Helps Clear Stuffed Up Noses and Respiratory Passages
NAC breaks down mucus in the nasal passages and the lungs.1 It does this by breaking apart bonds that hold the mucus together, reducing the mucus viscosity so the body can clear it out easier.1
NAC Is an Ideal Lung Supplement
NAC’s ability to break down mucus can support lung health in people with asthma, cystic fibrosis, chronic obstructive pulmonary disease(COPD), and bronchitis.4,5 Each of these disorders is characterized by the secretion of an excessive amount ofmucus.4,5
NAC’s antioxidant actions are also beneficial for the lungs. Combining 1,200 mg/day of NAC with conventional treatment for pneumonia led to reduced oxidative stress. It also supported a healthy inflammatory response.6
It Defends Against Germs
Bacteria living in colonies form a protective shield known as a biofilm. NAC may break down biofilms.7Scientists first demonstrated this property of NAC in 1997, when they found it could stop the bacterium Staphylococcus epidermidis from forming biofilms.8 Later research found it could block biofilm formation of a number of bacteria, including the dental pathogen Enterococcusfaecalis.9
NAC for the Kidneys?
In certain medical imaging tests, patients are given a contrast agent to help improve the visibility of certain organs, tissues, or blood vessels. Sometimes, these agents can damage the kidneys. In some studies, NAC supports the kidney health of people given a contrast agent.10,11
It May Support Neurological Health
In one study, patients who took 1,200 mg/day of NAC in combination with weekly intravenous NAC, had better neurological health and improvement in midbrain dopamine neurons.12 In another study, researchers found that high oral doses of NAC safely raised levels of NAC in the cerebrospinal fluid without any adverseeffects.13 However, in one other study, very high oral NAC doses (6,000mg/day) resulted in a worsening of symptoms, indicating more studies are needed to find out if NAC can be beneficial for neurological health.
NAC for Male and Female Fertility
There’s a lot of good research on NAC and fertility in both men and women. It can increase sperm count and sperm motility (the ability of sperm to swim to a female’s eggs).14 It also may protect the sperm from damage and maintains sperm shape and structure.14,15
In women, NAC protects ovarian follicles and ovarian tissue16 and triggers ovulation in women with polycystic ovary syndrome (when used together a fertility drug).17When combined with folic acid, NAC improves the birth rate in women with a history of unexplained recurrent pregnancy loss.18
An Antioxidant Supplement for Vibrant Good Health
I find in my clinical practice that NAC builds a strong foundation of overall health in my patients. It fortifies their immune systems, maintains healthy lungs, and promotes fertility, to name just a few of the health benefits of N-acetyl cysteine. NAC is a wonderful go-to supplement to have on hand for either short-term support or long-lasting good health.
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2. Whitehouse LW, Wong LT, Paul CJ, Pakuts A, Solomonraj G. Post absorption antidotal effects of N-acetylcysteine on acetaminophen-induced hepatotoxicity in the mouse. Can J Physiol Pharmacol. 1985;63(5):431-437.
3. De Flora S, Grassi C, Carati L. Attenuation of influenza-like symptomatology and improvement of cell-mediated immunity with long-term N-acetylcysteine treatment. Eur Respir J. 1997;10(7):1535-1541.
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10. Awal A, Ahsan SA, Siddique MA, et al. Effect of hydration with or without n-acetylcysteine on contrast induced nephropathy in patients undergoing coronary angiography and percutaneous coronary intervention. Mymensingh Med J. 2011;20(2):264-269.
11. Marenzi G, Assanelli E, Marana I, etal. N-acetylcysteine and contrast-induced nephropathy in primary angioplasty. N Engl J Med. 2006;354(26):2773-2782.
12. Monti DA, Zabrecky G, Kremens D, etal. N-Acetyl Cysteine May Support Dopamine Neurons in Parkinson's Disease: Preliminary Clinical and Cell Line Data. PLoSOne. 2016;11(6):e0157602.
13. Katz M, Won SJ, Park Y, et al. Cerebrospinal fluid concentrations of N-acetylcysteine after oral administration in Parkinson's disease. Parkinsonism Relat Disord. 2015;21(5):500-503.
14. Jannatifar R, Parivar K, Roodbari NH, Nasr-Esfahani MH. Effects of N-acetyl-cysteine supplementation on sperm quality, chromatin integrity and level of oxidative stress in infertile men. Reprod Biol Endocrinol. 2019;17(1):24.
15. Barekat F, Tavalaee M, Deemeh MR, etal. A Preliminary Study: N-acetyl-L-cysteine Improves Semen Quality following Varicocelectomy. Int J Fertil Steril. 2016;10(1):120-126.
16. Olesen H, Pors SE, Jensen LB, et al.N-acetylcysteine protects ovarian follicles from ischemia-reperfusion injury in xenotransplanted human ovarian tissue. Hum Reprod. 2021;36(2):429-443.
17. Badawy A, State O, Abdelgawad S.N-Acetyl cysteine and clomiphene citrate for induction of ovulation in polycystic ovary syndrome: a cross-over trial. Acta Obstet Gynecol Scand. 2007;86(2):218-222.
18. Amin AF, Shaaban OM, Bediawy MA.N-acetyl cysteine for treatment of recurrent unexplained pregnancy loss. Reprod Biomed Online. 2008;17(5):722-726.