The Benefits of NAC: Uncovering the Science

Iron. Vitamin C. Omega-3 and 6. Calcium. Vitamin D. Magnesium. Zinc. Vitamin B12.

This is a pretty good list of vitamins and minerals you should be getting on a daily basis. When you combine a daily multivitamin with a balanced diet, you’re oh so close to giving your body everything it needs.

Yes, you read that right – you’re close to giving your body the nutrients and support it needs to power you through your days. 

But there are a couple of pieces missing in this giant nutrition and whole-body health puzzle – amino acids and antioxidants. 

And more specifically, I want you to know about N-Acetyl-Cysteine (NAC). 

NAC is the supplemental form of the amino acid cysteine. Cysteine is one of three amino acids used by the body to create glutathione, a powerful antioxidant.*

The benefits of NAC are wide-ranging from supporting healthy lung function to providing antioxidant support through to liver and kidney detoxification. So yes, NAC is something you need to know about. 

Use this blog as your guide to NAC and learn:

  • What NAC is
  • How antioxidants and amino acids impact your health
  • The science behind NAC
  • Benefits of NAC

What is NAC?

NAC, or N-Acetyl-Cysteine, is the supplemental form of the amino acid cysteine. NAC has a range of functions in the body including as a precursor of glutathione, one of the body’s most important antioxidants.*

Glutathione is used by every cell and tissue in the body and is essential for combating free radicals that result from oxidative stress which can damage cells and tissues in the body.*

NAC offers powerful support for respiratory, liver, immune health, and antioxidant activity.*

Amino Acids, Antioxidants, and Your Health

Amino acids and antioxidants are essential to supporting and maintaining your whole-body health. 

  • Amino acids are the building blocks of protein. Your body relies on these amino acids to power essential chemical processes and functions including building and repairing muscles, supporting tendons and ligaments, making hormones, transporting oxygen in your blood, repairing cells, and more.1
  • There are 20 different amino acids in your body, categorized as essential and nonessential. There are nine essential amino acids that cannot be produced by your body and must come from your diet. The 11 nonessential amino acids are synthesized from essential acids.2
  • Among the 11 nonessential amino acids, eight - arginine, cysteine, glutamine, tyrosine, glycine, ornithine, proline, and serine - are classified as conditional amino acids. Your body needs conditional amino acids when you are stressed, run-down, or not healthy.2
  • Along with helping your body make protein, amino acids are essential to digestion, metabolism and energy, immune system support, hormone and brain chemical production, and tissue, skin, hair, muscle, as well as nail growth and repair.2
  • Cysteine, a nonessential amino acid is vital for your body to produce glutathione, a powerful antioxidant. Cysteine has a pivotal role in energy production and providing immune system support.3,4
  • Antioxidants are molecules that help defend against free radical damage to your cells. At high or persistent levels, free radicals cause oxidative stress in your body. This oxidative stress may damage your cells, cause inflammation, and contribute to health conditions including diabetes or cancer.5,6
  • Your body can produce antioxidants. These powerful molecules are found in fruits, vegetables, other whole plant-based foods, and in supplements.5
  • Glutathione is a potent antioxidant made up of three amino acids: cysteine, glycine, and glutamine. While your body can make glutathione, your glutathione levels can be impacted by age, stress, environmental toxins, and diet. Glutathione has a primary role in reducing oxidative stress and free radical damage. High or persistent levels of oxidative stress can be a precursor to a range of health conditions.7

I could keep writing and writing about amino acids and antioxidants! They are that important and complex. Understanding the benefits of NAC is a fundamental place to start this discussion.

The Science Behind NAC

The science behind NAC highlights these key functions in the body: 3,4,8,9,10,11

  • NAC is a vital precursor to the antioxidant glutathione. Research shows that supplementing with NAC may support increased levels of glutathione. This has positive benefits for defending against oxidative stress, free radical damage, and providing immune system and energy support.
  • NAC is widely studied for its effectiveness in providing support for respiratory medicine. Researchers are actively investigating the treatment impacts of NAC for conditions including bronchitis, asthma, cystic fibrosis, and chronic obstructive pulmonary disorder. NAC may act to help thin mucus in bronchial tubes to decrease coughing, wheezing, and respiratory challenges. 
  • A double-blind, randomized trial with 262 participants evaluated the efficacy of NAC in supporting improved respiratory and immune system health. The results of this 6-month study included a decrease in the frequency, severity, and length of influenza-like conditions and positive cell-mediated immunity.

The Benefits of NAC

The benefits of NAC include:12,13

  1. Detoxification support for your kidneys and liver, helping to limit damage to these organs caused by environmental toxins, heavy metals, liver disease, and to treat an acetaminophen overdose. 
  2. Glutathione production support which trickles over into protecting your body from oxidative stress and free radical damage.
  3. NAC acts to regulate glutamate levels in your brain. Glutamate is one of your brain’s most essential neurotransmitters and is required for day-to-day brain function. However, high levels of glutamate can have negative brain health impacts. 
  4. Providing relief for respiratory conditions, by acting as an antioxidant, expectorant, and anti-inflammatory in your lungs, bronchial tubes, and nasal system. 

I know blogs like this that are heavy on the science can be challenging – but I truly believe that knowledge is power. And I want you to have the power to make informed decisions about your health.

Thank you for being so invested in your health that you want to go deep and know what the science says. Here’s to always learning and growing!

Consult your healthcare team before making changes to your nutrition, exercise, or supplements. Discuss all supplements, including the vitamins and minerals you take or plan to take, as these may interact differently with underlying health conditions and medication. Always follow the suggested use instructions and read the warnings on the supplement product label before consumption.


  1. Protein: The Nutrition Source Harvard T.H. Chan School of Public Health (Accessed September 6, 2023)
  2. Amino Acids: (Accessed September 6, 2023)
  3. Cacciapuoti, F. (2019). N-Acetyl-Cysteine supplementation lowers high homocysteine plasma levels and increases Glutathione synthesis in the trans-sulfuration pathway. Italian Journal of Medicine. (Accessed September 6, 2023)
  4. Correia MJ, Pimpão AB, Fernandes DGF, Morello J, Sequeira CO, Calado J, Antunes AMM, Almeida MS, Branco P, Monteiro EC, Vicente JB, Serpa J, Pereira SA. Cysteine as a Multifaceted Player in Kidney, the Cysteine-Related Thiolome and Its Implications for Precision Medicine. Molecules. 2022 Feb 19;27(4):1416. doi: 10.3390/molecules27041416. PMID: 35209204; PMCID: PMC8874463. (Accessed September 6, 2023)
  5. Antioxidants Explained in Simple Terms: (Accessed September 6, 2023)
  6.  What is Oxidative Stress?: (Accessed September 6, 2023)
  7. lutathione Benefits: (Accessed September 6, 2023)
  8. Minich DM, Brown BI. A Review of Dietary (Phyto)Nutrients for Glutathione Support. Nutrients. 2019 Sep 3;11(9):2073. doi: 10.3390/nu11092073. PMID: 31484368; PMCID: PMC6770193. (Accessed September 6, 2023)
  9. Calverley P, Rogliani P, Papi A. Safety of N-Acetylcysteine at High Doses in Chronic Respiratory Diseases: A Review. Drug Saf. 2021 Mar;44(3):273-290. doi: 10.1007/s40264-020-01026-y. Epub 2020 Dec 16. PMID: 33326056; PMCID: PMC7892733. (Accessed September 6, 2023)
  10. Pirabbasi E, Shahar S, Manaf ZA, Rajab NF, Manap RA. Efficacy of Ascorbic Acid (Vitamin C) and/N-Acetylcysteine (NAC) Supplementation on Nutritional and Antioxidant Status of Male Chronic Obstructive Pulmonary Disease (COPD) Patients. J Nutr Sci Vitaminol (Tokyo). 2016;62(1):54-61. doi: 10.3177/jnsv.62.54. PMID: 27117852. (Accessed September 6, 2023)
  11. 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 Jul;10(7):1535-41. doi: 10.1183/09031936.97.10071535. PMID: 9230243. (Accessed September 6, 2023)
  12. Health Benefits of NAC: (Accessed September 6, 2023)
  13. What are the Health Benefits of NAC (N-Acetyl Cysteine)?: (Accessed September 6, 2023)

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Jenny Perez is an herbal educator, researcher, and writer who has been immersed in the field of nutrition and botanical medicine for more than 20 years. Jenny has created curriculum, content, and educational materials for Quantum Nutrition Labs, Premier Research Labs, the American Botanical Council, and Bastyr University’s Botanical Medicine Department where she was Adjunct Faculty, Herb Garden Manager, and Director of the Holistic Landscape Design certificate program.