Detox Learning Center

Top 12 Health Benefits of N-Acetyl Cysteine (NAC)

Imagine you have a toothache and pop too many acetaminophen (Tylenol) pills to deal with the pain. You end up with liver toxicity from the drug, and your doctor puts you on NAC to treat the overdose.

NAC (N-acetyl cysteine) is a common dietary supplement. But it’s also a top treatment doctors use to save your liver from acetaminophen poisoning. (1)

The main way NAC helps protect your liver from acetaminophen damage is by increasing your liver’s antioxidant defenses. (2)

So what exactly is NAC? This nutraceutical compound derives from cysteine. That’s an amino acid found in protein-rich foods, such as eggs, lentils, meat, and pumpkin seeds. (3)

Besides NAC’s impressive ability to protect your liver, NAC can also work throughout your body. That includes supporting the health of your brain, gut, and lungs. 

Here’s a closer look at the top 12 potential health benefits and uses of NAC.

1. Antioxidants

NAC packs a double punch when it comes to fighting free radicals. Those are pesky, unstable molecules that can damage your cells. When free radicals get out of control, its called oxidative stress, often associated with cancer, chronic diseases, and chronic inflammation. (4)

To fight this, NAC could work directly as an antioxidant to squelch free radicals. That can help reduce inflammation and preserve normal cell function. (4)

Second, the cysteine that NAC supplies is a key building block of glutathione. That’s a potent antioxidant your body makes to guard your cells against free radicals. (5, 6)

If you’ve heard of glutathione supplements, you may wonder why not take those rather than NAC? In other words, why not bypass “the middleman”?

Most glutathione supplements are quickly broken down in your gut or liver before they have a chance to work. Liposomal glutathione may work better, but those supplements are typically pricey. NAC is relatively inexpensive. (7, 8) Additionally, pushing glutathione directly too early can throw people into detox symptoms, whereas NAC is a precursor and supports your body in creating its own glutathione instead.

2. Biofilm Reduction

Biofilm is like a “protective blanket” that bacteria and other microbes produce. It helps shield them from your immune system and treatment strategies. (9)

To beat complex chronic illnesses, such as Lyme disease, it’s important to tackle biofilm. NAC may help with this. Though NAC hasn’t been tested against Borrelia (Lyme) biofilm, it has been tested against other resistant bacteria.

In a series of experiments, researchers tested NAC against seven types of antibiotic-resistant bacteria. That included MRSA (methicillin-resistant Staphylococcus aureus). Compared to a control group, NAC significantly reduced the thickness of biofilm made by all bacteria tested.

In addition, all the bacteria tested died within 30 minutes of treatment with NAC. Plus, NAC inhibited the growth of Candida albicans. (10)

Another lab study suggests NAC inhibits biofilm production in a dose-dependent manner. In other words, the effectiveness increases as the dose increases. (11)

3. Brain Function

Supports Healthy Brain Function

Your brain has a big workload but relatively low antioxidant defenses, so it’s vulnerable to damage. Plus, as you age, oxidative stress increases while glutathione levels gradually decrease. This means your brain has even less protection. (12)

You’d probably prefer not to think about your risk of a brain injury or losing good cognitive function. Yet, it’s a possibility we all face.

Brain dysfunction and memory loss can happen as a result of brain injuries, such as a stroke, as well as in Alzheimer’s disease. Oxidative stress could play a significant role in this, as it promotes inflammation and dysfunction of brain cells.

Research suggests NAC may help combat cognitive dysfunction in conditions including:

  • Alzheimer’s disease: Scientists have tested NAC for people with declining brain function, including early Alzheimer’s disease. When combined with certain vitamins and amino acids, NAC has helped improve people’s executive function. That’s the ability to carry out tasks requiring mental skills. (12)
  • Parkinson’s disease: NAC may help your brain use dopamine, a nerve messenger that declines in Parkinson’s. When people with Parkinson’s disease took NAC via a combo of an oral supplement and intravenous therapy, dopamine activity increased by 3–8%. (13)
  • Stroke: During a stroke, your brain produces a toxin called acrolein. Animal research suggests NAC may help detoxify this harmful compound. NAC helps increase glutathione levels in your brain, which can play a role in combating acrolein. (14)
  • Traumatic brain injury: NAC may help reduce symptoms of brain injury incurred during military service. When soldiers took NAC within 24 hours of a mild brain injury, they had an 86% chance of full recovery within 7 days compared to taking a placebo. (15)

4. Gut Health

Modern science confirms you need a healthy gut and microbiome for optimum wellness. NAC may be a powerful tool for helping you maintain intestinal health, including the function of your gut wall. 

Your gut lining is like a security system. It releases valuable nutrients into your bloodstream while minimizing the passage of harmful elements. That’s good for the rest of your body but leaves your gut vulnerable to toxins and increases your risk of developing a leaky gut.

When researchers fed animals NAC for three weeks, it reduced leaky gut. Plus, it decreased intestinal inflammation caused by toxins. NAC may also provide these gut protective effects in ulcerative colitis, an inflammatory bowel disease. (16, 17)

NAC may promote a healthy gut microbiome as well. In a five-month mouse study, NAC stimulated the growth of beneficial gut bacteria. At the same time, it decreased the abundance of bacteria that promote disease, including type 2 diabetes. NAC might also reduce the amount of toxins that harmful gut bacteria produce. (18)

5. Liver Health

Your liver processes toxins—including drugs like acetaminophen—so you can eliminate them.

Unfortunately, intermediate compounds produced in liver detox can be more damaging than the starting substances. Some of these intermediates can bind to your DNA, possibly acting as carcinogens. And some may bind to proteins, potentially triggering unwanted immune responses. (19)

NAC could help protect your liver during its detox work. In today’s toxic world, everyone’s liver could likely use a little help.

Remember, NAC promotes glutathione production, particularly in the liver. This is especially helpful during detox when oxidative stress increases in liver cells. (20, 21)

Another challenge that’s on the rise is nonalcoholic fatty liver disease (NAFLD). That refers to unhealthy fat buildup in the liver that’s not due to alcohol intake. NAFLD is often related to obesity and type 2 diabetes.

A study of people with NAFLD suggests NAC can help to reduce liver enzymes. That's a sign it helps to lower inflammation. As a result, NAC may help improve liver function in people with NAFLD. (22)

So NAC is pretty impressive by itself. It also teams up well with TUDCA (tauroursodeoxycholic acid). That’s a water-soluble bile acid and liver helper. 

Animal research suggests that when you combine NAC and TUDCA, they fight free radicals in your liver better than when taken alone. (23)

6. Lung Function

Supports Lung Function

NAC is recognized for its respiratory benefits. The antioxidant properties of NAC could help protect your lungs. On top of that, NAC is a mucolytic. This means it helps thin and reduce mucus. (20)

NAC may be beneficial for people with several lung conditions, including:

  • Chronic bronchitis: In this condition, the airways of your lungs swell and produce mucus, leading to coughing. A review of human studies found that taking NAC was 68% more likely to improve bronchitis symptoms compared to taking a placebo. (24
  • Chronic obstructive pulmonary disease (COPD): This lung disease involves high free radical levels, which deplete your glutathione. NAC may help reduce lung inflammation while increasing glutathione levels. (25
  • Cystic fibrosis (CF): This genetic disease involves excess mucus production, which promotes bacterial growth in the lungs. When people with CF took NAC for six months, they maintained or even improved their lung function. In contrast, lung function declined in the placebo group. (26)
  • Mold-infected lungs: In a small study, people with an Aspergillus (mold) lung infection nebulized a special preparation of NAC. About 33% of them experienced reduced lung symptoms and increased mucus removal. (27

7. Mental Health

NAC can cross your blood-brain barrier. So the compound may act in a few different ways to combat mental health conditions.

In your brain, NAC supplies cysteine to make glutathione. This may help combat the oxidative stress common in many psychiatric disorders. These include depression, obsessive-compulsive disorder, and schizophrenia. (28)

Also, NAC supports key neurotransmitter (nerve messenger) systems, including glutamate. Several mental health challenges—including addiction and schizophrenia—involve dysfunction of the glutamate system. (29)

On top of that, NAC may help calm inflammation commonly found in people with depression and other mental health disorders. That might help balance neurotransmitter levels and restore their normal function. (29, 30)

Several human studies support the mental health benefits of NAC. For example, in a three-month study, people with depression who took NAC alongside their regular treatment had a significant reduction in depression symptoms, compared with regular treatment alone. (31)

8. Parasites

Parasites are messy “houseguests,” generating free radicals and toxins. NAC may help bolster your defenses against parasitic invaders.

NAC helps fight Plasmodium, a parasite that infects the blood and causes malaria. Could it also combat Babesia? That’s another parasite that can infect your blood. You may know Babesia better as a Lyme coinfection. (32)

To combat Babesia, your body generates free radicals. But those can also damage your cells and tissues. A lab study suggests NAC could help prevent oxidative damage to the host while inhibiting Babesia growth. (33)

NAC may also be effective against some parasitic worms, including Schistosoma mansoni. When mice with the parasite took NAC, it increased glutathione levels and counteracted the oxidative stress caused by the worm. (34)


Polycystic Ovary Syndrome (PCOS) is a condition that affects up to 10% of women in their reproductive years. It’s characterized by an imbalance in reproductive hormones. (35)

PCOS can lead to infertility. Common symptoms include acne, increased facial hair, menstrual irregularity, thinning of scalp hair, and weight gain. (36)

It’s not completely clear why PCOS occurs. Genetics may play a role. An inability to use insulin properly is often a factor too. (37)

Research suggests NAC may offer several benefits to women with PCOS. In one study, women with PCOS took NAC for six months. Their fasting blood sugar, fasting insulin level, and weight improved more than a comparison group taking metformin. That’s a standard diabetes drug. (38)

NAC may help with fertility in PCOS as well, according to a review of eight clinical studies. Women with PCOS who took NAC were more likely to get pregnant than women taking a placebo. (39)

10. Pesticides

May Help Protect Against Pesticides

Researchers have tested NAC against some toxic pesticides. This includes organophosphate pesticides, which are often used to kill insects.

A top example of an organophosphate pesticide is chlorpyrifos. This insecticide is used to help grow some fruits, nuts, and vegetables. But it can harm your brain and nervous system. Environmental health advocates have been calling for a complete ban of this insecticide for years. (40)

In a study of people with organophosphate pesticide poisoning, NAC enabled people to take smaller doses of a drug typically used to treat the poisoning. (41)

NAC may also combat the harmful effects of paraquat. This weed killer is used to grow crops across the globe. In a lab study, NAC neutralized free radicals triggered by paraquat exposure. (42)

Last but not least, NAC may help counteract harmful effects of glyphosate. In one study, NAC helped protect rats against oxidative stress and tissue damage caused by a glyphosate weed killer. (43)

11. Toxic Heavy Metals

Along with testing NAC against toxic pesticides, it’s also been tested against toxic heavy metals.

You can take steps to reduce your exposure to harmful heavy metals, like mercury in seafood, but you can’t completely avoid them. This is why you need ways to bind and remove toxic heavy metals. 

A potent tool to bind and eliminate harmful heavy metals is carbon-based binders. But NAC may help in this area too.

Due to its chemical structure, NAC can bind heavy metals like cadmium, lead, and mercury. That enables you to excrete them, including via your urine. (44)

In one case study, a man given high doses of NAC for 10 days had an 86% drop in blood levels of the heavy metal cobalt. He had elevated cobalt levels due to a deteriorating metal hip replacement. Six months after his NAC treatment, his cobalt levels remained low. (45)

In addition, the antioxidant properties of NAC may help combat the damaging effects of heavy metals. Remember, NAC can act as an antioxidant directly. It also supports the production of glutathione in your cells. (46)

12. Viruses

If you have a weakened immune system or a tendency to catch viruses, you may want to consider NAC.

Lab studies suggest NAC inhibits the replication of some seasonal influenza A viruses. It may also reduce inflammation triggered by the flu virus. That said, NAC’s effectiveness appears to vary with the strain of the flu virus. (47, 48)

Still, even if NAC doesn’t completely prevent a flu virus infection, it may reduce the symptoms. Further research is needed to confirm which flu strains NAC combats best. (48)

One virus you’d likely prefer to bypass is the common rotavirus. It can cause diarrhea and vomiting, especially in children. But it can also infect adults. (49)

When researchers tested NAC against rotavirus in the lab, it inhibited rotavirus activity by 93%. In contrast, some drugs tested in the study only inhibited the virus by 35–53%. In addition, in one small study, children who took NAC at the start of a rotavirus infection had significantly reduced episodes of diarrhea. (5051)

NAC’s Many Health Benefits

As you’ve seen, NAC is a bit of a “jack-of-all-trades” when it comes to supporting your health. It may offer several benefits simultaneously.

Many of NAC’s benefits relate to its ability to improve antioxidants and glutathione. That helps protect your cells, organs, and tissues against free radical damage.

NAC could be particularly helpful in your detox journey. Its ability to support brain, gut, and liver health is often needed in complex chronic illnesses.

An especially good way to get NAC is in combination with TUDCA. This combo helps provide optimal liver protection to support detox and your health journey.  

Are you taking advantage of the powerful combo of TUDCA and NAC?

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