NAC: The Incredible Amino Acid for Your Lungs, Liver, and Longevity (2022)

What is NAC?

NAC stands for n-acetyl cysteine, which is the supplement form of the amino acid cysteine, found in protein foods like chicken, eggs, and fish. Amino acids like cysteine help the body with numerous functions like building and repairing DNA, metabolism, and immune function.

Many of NAC’s benefits come from its ability to act as a precursor–or building block–to glutathione, your body’s most powerful antioxidant that works to reduce damage done by free radicals all over the body. Free radicals play a role in almost every major modern disease, including diabetes, cancer and Alzheimer’s.

Antioxidants (like glutathione) neutralize free radicals. Integrative medicine doctors address antioxidant function when treating chronic illnesses. In other words, NAC can help combat cell damage throughout the body. It’s truly a jack of all trades when it comes to supporting different body systems.

Learn more: IV Therapy to increase antioxidants.

NAC Helps Your Body Make Glutathione

Why is helping your body make more glutathione so important? According to one study, glutathione may impact longevity by fighting the negative effects of oxidative stress that lead to many chronic diseases (1).

Coincidentally, you actually already make our own glutathione. But unfortunately, plenty of things–including a poor diet, sedentary lifestyle, medications, stress, aging, and illnesses–can quickly deplete this antioxidant that is absolutely crucial for healthy cell function.

You can see how these behaviors can compound pretty fast to result in glutathione being in short supply.

Normally your body can also recycle glutathione, except when your toxic load becomes too high. Then, you’ve developed an even bigger problem because glutathione also “recharges” other antioxidants such as vitamin C and vitamin E, which all help to fight free radical damage together.

This means that lowered glutathione levels ramp up oxidative stress, inflammation, infections, and irregular cell growth. Decreased glutathione can also overload your liver, making it harder to detoxify (more on detox later).

(Video) How to Take the Amino Acid NAC

Functional medicine detox: Core Restore 7-Day (chocolate or vanilla)

Low Glutathione Levels Linked with Chronic Disease

Many people who struggle with common chronic illnesses have depleted glutathione levels, including those with chronic fatigue syndrome (myalgic encephalitis, ME ), heart disease, cancer, chronic infections, autoimmune disease, diabetes, Alzheimer’s disease, Parkinson’s disease, kidney problems, and liver disease (2).

Optimizing glutathione status is one functional medicine treatment

Your body’s ability to produce and maintain adequate glutathione levels is vital to recovery from illness, disease prevention, and maintaining optimal health.

And that’s exactly why NAC is such a jack of all trades when it comes to supporting health.

Shop Numedica N-acetyl L-cysteine.

NAC Supports Detox in Your Kidneys and Liver

Much of the extensive research done with NAC looks at detox function, and its ability to protect both the kidneys and liver from damage.NAC: The Incredible Amino Acid for Your Lungs, Liver, and Longevity (1)

Notably, intravenous NAC is used in clinical settings as an antidote for hepatotoxicity due to acetaminophen overuse. Hepatotoxicity refers to liver damage due to medications, drugs, or chemicals.

(Video) 4 Most Liver Damaging Supplements (Avoid Over Usage)

The form of NAC given to patients in this instance aids in metabolizing a toxic byproduct of acetaminophen called n-acetyl-benzoquinoneimine, which rapidly depletes the body’s glutathione. NAC is thought to be hepatoprotective because it replenishes glutathione.

NAC is also important for phase II liver detoxification, helping to neutralize and package up toxins for excretion that were created in phase I.

NAC may even help prevent side effects from environmental toxins, such as exposure to heavy metals like mercury, cadmium, lead, and arsenic (3).

May Improve Brain Health

Research shows a positive effect of NAC supplementation for conditions such as Alzheimer’s, in addition to improving depressive symptoms and mood.

  • Mood and Depressive Symptoms – In one analysis, NAC “reduced depressive symptoms and resulted in an overall increase in functionality” (4).
  • Alzheimer’s Disease – NAC may help ameliorate some of the oxidative damage caused by mitochondrial dysfunction that is linked to Alzheimer’s disease. Healthy mitochondria are an important part of protecting against neurodegenerative disease, so supporting their function is key (5).

NAC for Immune Health + Autoimmune Disease

Because of its ability to support healthy immune function, antioxidant status, and modulate inflammation, NAC is an important consideration in the treatment of illnesses affecting the immune system.NAC: The Incredible Amino Acid for Your Lungs, Liver, and Longevity (2)

Decreased viral illness – One study showed reduced transmission and decreased symptom severity in influenza-like episodes in elderly patients who were receiving 600 mg/day NAC for 6 months. Further, 79% of people in the placebo group developed symptoms after infection, while only 25% of those infected in the NAC group developed symptoms (6).

NAC May Improve Autoimmune Disorders

Autoimmune diseases are worsened by inflammation in the body. Frequently, reducing this inflammation can improve symptoms–sometimes significantly.

Because NAC is a precursor to glutathione, it can help reduce the systemic inflammation that can worsen many autoimmune disease symptoms.

(Video) What is NAC (N-Acetyl-L-Cysteine)?

NAC has also been shown to inhibit certain inflammatory cytokines, making it a potential treatment for Th1-mediated autoimmune diseases (7).

Note: Autoimmunity is a complex condition that often requires multiple integrative medicine solutions, but NAC may be one form of functional support available.

Improves Lung Health

NAC is also useful to help fight long-term lung damage in those with chronic obstructive pulmonary disease (COPD) (8). In 2016, a review in the Journal of Respiratory Medicine concluded that NAC either alone or with antibiotics can help decrease symptoms or worsening of conditions such as COPD and chronic bronchitis (9).

Preliminary research also shows a promising link between NAC and potentially decreasing the severity of COVID-19 (10). Glutathione deficiency appears to be a crucial factor driving oxidative damage in the lungs and–as a result–leads to serious outcomes, such as acute respiratory distress syndrome (ARDS) and multiorgan failure (11).

There are clinical trials underway examining the effectiveness of NAC with coronavirus patients.

Boosts Fertility in Men and WomenNAC: The Incredible Amino Acid for Your Lungs, Liver, and Longevity (3)

Because of its ability to support antioxidants in the body, NAC has the potential to help with fertility in both women and men, in addition to improving hormone-related conditions like PCOS.

Improves sperm quality – Oxidative damage in semen is associated with sperm damage and dysfunction. Daily supplementation with NAC has been shown to improve both sperm motility and quality, in addition to decreasing oxidation of sperm DNA (12).

NAC for PCOS Symptoms – In a trial involving 100 women with PCOS, researchers compared the blood-sugar regulating drug, Metformin (commonly prescribed for PCOS) with NAC. Women were given 600 mg of NAC three times a day or 500 mg metformin three times daily. They found that both treatments significantly reduced menstrual irregularities, free testosterone, and insulin levels (13).

(Video) How Does NAC (N-Acetylcysteine) Work

A systematic review also found that NAC supplementation improved pregnancy and ovulation rates in women with PCOS (14).

NAC Can Destroy Biofilms

Harmful organisms in your gut form protective biofilms to shield themselves from your immune system and antibiotics. Healthy levels of friendly bacteria help fight biofilm defenses to allow your immune system to naturally eradicate harmful bacteria. For many people, however, there may not be enough friendly bacteria to break down these biofilms and this contributes to digestive imbalances such as SIBO and others.

N-acetyl cysteine can help break down the biofilms that harmful bacteria hide behind, and it’s also useful alongside antibiotic or antimicrobial herbs when treating a bacterial overgrowth or imbalance.

This means NAC helps disarm harmful bacteria, so that medications or therapies can reach the vulnerable part of the cell to do their job of ridding it from your body.

Protects Against Inflammation Caused by Oxidative Damage

Inflammation plays a role in the development of almost all modern diseases, including diabetes, obesity, neurodegenerative disease such as dementia, and heart disease.

Inflammation is largely produced often by oxidative damage as a result of an imbalance in free radicals vs. antioxidants. Antioxidants work to neutralize unstable, harmful free radicals to support cellular health and tissue function.

NAC is important for the production of glutathione, a powerful antioxidant, which can help reduce the oxidative stress that drives inflammatory processes.

Simply put, more antioxidants equals less oxidative damage and inflammation.

(Video) NAC: Super Supplement for Hormones, Liver, Lung, Brain Health and SO MUCH MORE!

The Bottom Line

N-acetyl cysteine has a long and varied history for supporting many different beneficial mechanisms in the body. It’s an amino acid that plays a significant role in optimal detoxification processes, lung health, and immune function. Because of this, it may even help reduce the severity of viral illness like COVID-19.

NAC’s unique ability to increase the production of glutathione can help integrative medicine doctors optimize antioxidant function to decrease oxidative stress which drives inflammation and disease.




Does NAC help repair lungs? ›

NAC supplements have been used to improve COPD symptoms, exacerbations, and lung decline ( 19 , 20 , 21). A review of multiple studies found that 600 mg of NAC twice a day significantly improved lung function and symptoms in those with stable COPD and that higher doses were more effective than lower ones ( 22 ).

Can NAC reverse liver damage? ›

N-acetylcysteine can improve liver function in patients with non-alcoholic fatty liver disease. Better results may be achievable in a longer follow up.

How much NAC should I take to detox my liver? ›

The most commonly used doses range from 600-1,800 mg daily and clinical studies have found that doses of up to 2,000 mg/day are safe. Many researchers have come to the conclusion that a deficiency of liver glutathione is one of the leading factors that allow liver disease to progress.

Can NAC cause liver damage? ›

Taken together, NAC has a dual effect on acute ethanol-induced liver damage. Pretreatment with NAC prevent from acute ethanol-induced liver damage via counteracting ethanol-induced oxidative stress. When administered after ethanol, NAC might behave as a pro-oxidant and aggravate acute ethanol-induced liver damage.

Is it OK to take NAC everyday? ›

Twice daily administration or three times daily administration is commonly recommended by the manufactures. There is no recommended daily allowance for NAC, because unlike vitamins, it's not an essential nutrient.

Can NAC reverse lung damage? ›

Conclusions: NAC attenuates lung damage, pulmonary emphysema and alveolar septal cell apoptosis by partly reversing the decrease in VEGF secretion and VEGFR2 protein expression in smoking-induced COPD in rats.

Why is NAC no longer available? ›

As we discussed in a recent response to two citizen petitions, the FDA has determined that NAC is excluded from the dietary supplement definition under the FD&C Act because NAC was approved as a new drug before it was marketed as a dietary supplement or as a food.

How long can I take NAC supplement? ›

Children: N-acetyl cysteine is likely safe when taken by mouth in doses of 900-2700 mg daily for up to 12 weeks.

Does NAC raise blood pressure? ›

Additionally, in human studies, using NAC as an adjunct to other antihypertensive therapies results in a decrease in blood pressure (38–40).

What can you not take with NAC? ›

Treatment with NAC may strengthen the effects of some medications that suppress the immune system, such as azathioprine (Imuran), cyclophosphamide (Cytoxan), or prednisone (Deltasone). Do not take NAC with these medications without talking to your doctor first.

Does NAC affect sleep? ›

NAC treatment also attenuated the sleep deprivation increased MDA levels and decreased GSH levels in the brain. against sleep deprivation-induced cognitive dysfunctions, anxiety like behaviour and oxidative stress.

Does NAC clean liver? ›

NAC plays a role in the detoxification of your kidneys and liver. It can help to prevent potential side effects of drugs and environmental factors — such as exposure to heavy metals — that may impact these organs.

Does NAC cause weight loss? ›

Hildebrandt et al. demonstrated that NAC may reduce fat mass in a trial including human subjects receiving either NAC or placebo for 8 weeks ((74)). The NAC group (N = 11) featured a 3% decrease in fat mass compared to an 8% increase in the placebo group ((74)).

When is the best time to take NAC? ›

When Should I Take NAC? Like other amino acid supplements, NAC should be taken either 30 minutes before, or two hours after, eating to avoid competing with protein for absorption. For cold and flu, start taking NAC as soon as symptoms appear.

Do you need to take vitamin C with NAC? ›

No interactions were found between NAC and Vitamin C.

Can NAC help with Covid? ›

Despite greater baseline risk, use of NAC in COVID-19 patients was associated with significantly lower mortality (OR 0.56; 95%CI 0.47-0.67), a finding that remained significant in a multivariate analysis adjusting by baseline characteristics and concomitant use of corticosteroids.

Does NAC help with energy? ›

Conclusion. Dietary NAC did not affect energy status but enhanced the hepatic antioxidant capacity by increasing the activities of antioxidant enzymes in cold-stressed broilers.

Does NAC clear mucus from lungs? ›

NAC (N-acetyl cysteine) helps break down mucus. For that reason, inhaled NAC is used in hospitals to treat bronchitis. NAC may also protect lung tissue through its antioxidant activity.

How long does it take for NAC to work for COPD? ›

Inflammation and oxidative stress in COPD

Namely, NAC decreased the chemoattractant properties of the sputum of COPD patients after 10 month treatment (van Overveld et al 2000) and modulated the inflammatory response after 10 weeks of intake (Sadowska et al 2005).

How do you fix lung scarring? ›

The lung scarring that occurs in pulmonary fibrosis can't be reversed, and no current treatment has proved effective in stopping progression of the disease. Some treatments may improve symptoms temporarily or slow the disease's progression. Others may help improve quality of life.

Does NAC break up mucus? ›

N-acetylcystine (NAC) is a mucolytic medication, meaning that it breaks apart mucus. Investigators know that mucus is a factor in severe asthma attacks. However, mucus may be a factor in chronic severe asthma as well.


1. The AMAZING Health Benefits of NAC ( N-Acetyl Cysteine)
(Dr. Nick Zyrowski)
2. Banned! Why is NAC Getting Removed from Shelves?
(Thomas DeLauer)
(Mimi Von Snatch)
4. NAC (N-acetyl cysteine) & Glutathione Update | Don't Freak Out Just Yet
(High Intensity Health)
5. How To Repair Liver Damage After Alcohol? – Dr.Berg on Liver Cirrhosis
(Dr. Eric Berg DC)
6. NAC N-Acetylcysteine
(Drbeen Medical Lectures)

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