All powerful NAC benefits and applications

By Nootropic Blend staff

N-acetylcysteine (NAC) is a remarkably versatile antioxidant supplement with numerous health benefits that might be of great importance to millions of people. 

If there are secret home remedies, this one should be on the list. It’s because NAC has the power to assist in so many ‘chronic’ conditions. For example chronic lung, respiratory, mood, or brain-related issues, and many more.

In fact, science is equally impressed by its functionality as well as still in doubt about how it can do all these actions. A lot of research is done and you can read more about it in our guide to NAC benefits.

Table of Contents

NAC therapy

A long time ago, pharmaceutical companies incorporated it into various patented drugs, and NAC was widely sold out for its ability to exorcise the hangover and decrease the symptoms of galloping influenza. It is also typically used in dietary, bodybuilding, and skin health supplements

As well as an adjunctive treatment in the major clinical trials and experiments for unresolved health conditions and diseases. 

NAC therapy in paracetamol (acetaminophen) intoxication is standard clinical practice. Doctors regularly give intravenous NAC to people with an acetaminophen overdose to prevent or reduce kidney and liver damage (1). 

It has been used as a beneficial drug treatment for some disorders such as polycystic ovary syndrome patients with CC resistance, preterm birth, RPL, chronic bronchitis, ulcerative colitis, liver cancer, muscle performance, hemodialysis, asthma, Alzheimer’s, and Parkinson’s. (2)

More than 20 clinical trials have employed NAC in various psychiatric disorders. These include nicotine and cocaine addiction and cessation, methamphetamine and cannabis dependence, pathological gambling, trichotillomania, nail-biting and skin picking, schizophrenia, bipolar disorder, and autism. In most of these studies, NAC had positive effects on clinical outcomes (3).

new applications of NAC

Beyond that particular application, NAC has remained a relatively obscure and poorly understood compound until quite recently. 

An innovative theory of an immune-inflammatory condition that arises from oxidative stress is a baseline for the new applications of NAC

Its effectiveness as a free-radical scavenger, since it is a precursor of natural (“endogenous”) glutathione, gave us promising novel studies that try to help with mental health disorders such as obsessive-compulsive disorder (OCD), anxiety, and depression

health benefits of nac supplement

structured formula of NAC molecule

The alphabet of NAC benefits  → A-CD-GH-KL-NO-SU-Z



As many addictive disorders have limited or currently ineffective treatment options, NAC may be an effective adjunctive therapy for individuals with these conditions (17). 

NAC has the capacity to restore homeostasis to brain glutamate systems disrupted in addiction and thereby reduce craving and the risk of relapse.


The research found that the best approach is to use NAC while you are trying to quit smoking. If you are slowly reducing your cigarette usage, it will help protect your lungs Photo by Thomas Stephan on Unsplashfrom further damage, and it may help reduce your cravings based on research on other addictive behaviors.

In a pilot study, supplementation of 2,400 mg of N-acetylcysteine daily to nicotine-addicted smokers noted that after two weeks there was a trend to reduce the number of cigarettes smoked daily. The magnitude of reduction appeared to be around 25%.


NAC decreases withdrawal symptoms and prevents relapse in cocaine addicts (18). Some early research shows that taking N-acetyl cysteine by mouth reduces the desire to use cocaine in cocaine-dependent people. But conflicting results exist (19).


Additionally, preliminary studies show that NAC may decrease marijuana and nicotine use and cravings (2021). But further studies will be needed to investigate these possibilities.

By regulating glutamate levels in your brain, NAC may alleviate symptoms of multiple psychiatric disorders and reduce addictive behavior.

There is accumulating evidence on the use of N-acetylcysteine (NAC) in the treatment of patients with neuropsychiatric disorders. 

As a multi-target drug and a glutathione precursor, NAC can help in the management of stress-related disorders. There is an expanding field of research investigating novel therapies targeting oxidative pathways.

Photo by Kayla Hatwood on UnsplashThe aim of this newest study was to investigate the effects of NAC in zebrafish submitted to unpredictable chronic stress (UCS). NAC reversed the anxiety-like behavior and oxidative damage observed in stressed animals (22).

The dangerous outcomes of chronic stress and anxiety in the central nervous system are an outcome of glutamatergic hyperactivation, glutathione (GSH) depletion, oxidative stress, in addition to boosted inflammatory response, amongst others.

NAC concentrations overall do not interfere with the activity of the most commonly used antibiotics, except for carbapenems.

  • doribax.
  • doripenem.
  • ertapenem.
  • imipenem/cilastatin.
  • Invanz.
  • meropenem.
  • meropenem/vaborbactam.
  • merrem IV.

A modulatory effect on the activity of other beta-lactams and aminoglycosides was also observed at the highest NAC concentration, resulting in either synergistic or antagonistic interaction. Interestingly, NAC showed intrinsic antimicrobial activity against H. influenzae, which deserves further investigation (23).

NAC reduced ADHD symptoms in small-sized research on ADHD within a systemic lupus erythematosus (SLE) population (24).

NAC reduced ADHD symptoms as determined by the ADHD Self-Report Scale Sign List (ASRS).

This evidence requires to be solidified with the fact that the study population struggled with SLE and therefore can not be generalized as a treatment for common ADHD.

Blood sugar

High blood sugar and weight problems contribute to inflammation in fat tissue. This can lead to damage or destruction of insulin receptors and put you at a higher danger of type 2 diabetes. N-acetylcysteine suggests a helpful impact on insulin level of sensitivity and offers the possibility for brand-new treatment approaches for insulin resistance (25).

Animal research studies show that NAC may support blood sugar levels by decreasing inflammation in fat cells and consequently enhancing insulin resistance. NAC supplements inhibited the boost of fat mass and the advancement of weight problems when mice were fed with a high-fat diet (26, 27).

When insulin receptors are undamaged and healthy, they effectively remove sugar from your blood, keeping levels within normal limitations.

Bear in mind that human research on NAC is needed to validate these effects on blood glucose control.

Osteoarthritis is the most common joint disorder with increasing global prevalence due to the aging of the population. No medicines can’t really halt or reverse the condition, with the only treatment being pain relievers.

In an animal study, NAC was provided to the mice with osteoarthritis, and it reduced the level of joint damage to that seen in healthy, control mice.

The study suggests that NAC can operate as an osteogenesis-enhancing molecule to accelerate bone regeneration by activating the distinction of osteogenic lineages (28).

Traumatic brain injury (TBI), known as the “silent epidemic”, contributes to worldwide death and disability more than any other traumatic insult. It can be caused by sports injuries, work accidents, car, and motorcycle accidents falls, and especially on the battlefield.

The TBI affecting cognition, motor function (movement), and personality. In a brain subjected to TBI, there is glutamate toxicity, free-radical injury to brain cells, electrolyte imbalances, mitochondrial dysfunction, inflammation, apoptosis (cell death), and stroke.

Photo by Chuanchai Pundej on Unsplash

A double-blind, placebo-controlled study was conducted with 81 active duty service members at a forward-deployed field hospital in Iraq. All service members in this study were exposed to significant blasts on the battlefield and met the criteria for TBI (29).

Service members were randomly assigned to receive either a placebo or N-Acetyl L-Cysteine (NAC) for 7 days.

The conclusion was that NAC is a safe pharmaceutical countermeasure of blast-induced TBI. Further work on long-term outcomes and the potential use of NAC in civilian mTBI is warranted.

Cognition and brain health

The available data suggested statistically significant cognitive improvements following NAC treatment, though the paucity of NAC-specific research makes it difficult to determine if this effect is meaningful. While NAC may have a positive cognitive effect in a variety of contexts; larger, targeted studies are warranted, specifically evaluating its role in other clinical disorders with cognitive sequelae resulting from oxidative stress and neuroinflammation (30).

N-acetylcysteine (NAC) is a glutathione precursor with potent antioxidant, pro-neurogenesis and anti-inflammatory properties and a favourable safety profile. 

This is widely attributed to NAC’s antioxidant effects.

A 2013 study found that NAC injections significantly reduced the negative effects of chemotherapy – specifically cisplatin – on the kidneys and ears (31).

In a 2014 study, NAC helped reduce inflammation and ulcers caused by chemotherapy in leukemia patients (32).

Developmental disorder

Although the anti-inflammatory and anti-oxidative roles of NAC are suggested for the reduction of symptoms of autism, its exact mechanism is not clear.Photo by Brandon Zack on Unsplash

A study from 2011 in Hafez Hospital at Shiraz, Iran, saw an improvement in several symptoms to an eight-year-old boy patient who was diagnosed with autism disorder. There was a significant reduction in his nail-biting behavior, and in his autism symptoms 30 days after the onset of NAC administration.

Also, his social interaction has significantly increased, as well as the reduction of aggressive behavior.

This case report suggests that NAC may play a potential role in treating autism (33).

Hey, if NAC is a good mucolytic for you, it can be for your dog, too. Here’s one review from a female on treatment with NAC.Photo by from Pexels

I give 600 mg in a.m. and 600 mg in p.m. to my old dog who has breathing problems and a cough. Works very well. I take the same dosage myself with good results for asthma.

Ears and eyes protecting

In a double-blind, placebo-controlled crossover trial of 26 people with Sjogren’s syndrome, the use of NAC at a dose of 200 mg 3 times per day improved eye-related symptoms (34). The supplement also showed some promise for mouth-related symptoms, but the effects were less clear-cut. While these are promising results, a much larger trial would be necessary to fully document the potential benefits of this treatment approach.

Blepharitis is a common eye disease that affects the edge of the eyelids and the Photo by Soroush Karimi on Unsplasheyelash hair follicles. Small studies have shown acetylcysteine to be of benefit to people with blepharitis.

Photo by Ahsan S. on Unsplash

Again, researchers indicate that this may be attributed to NAC’s powerful antioxidant abilities (35).

A 2014 study explored NAC in relation to noise-induced hearing loss in textile workers exposed to continuous noise in daily working. After 14 days, researchers concluded that NAC and ginseng helped reduce hearing loss associated with occupational noise. However, the NAC group was shown to have the most positive effects (36).

Fertility in male and female

Photo by on Unsplash

Approximately 15% of all couples trying to conceive are affected by infertility. In almost half of these cases, male infertility is the main contributing factor (37).

Many male infertility issues increase when antioxidant levels are insufficient to combat free radical formation in your reproductive system. Oxidative stress can cause cell death and reduced fertility (38).

In vitro studies showed positive effects with varying doses of NAC. It seems to improve male fertility by preserving sperm motility and reducing DNA damage.

In vivo studies gave conflicting results though. Except the one combining therapy with 600 mg of NAC and 200 mcg of selenium for 26 weeks that improved semen quality (39).


In one study, 35 men with varicocele were given 600 mg of NAC per day for three months post-surgery. The combination of surgery and NAC supplement improved semen integrity and partner pregnancy rate by 22% compared to the control group (40). Researchers suggested that this combined supplement should be considered as a treatment option for male infertility.


In addition, NAC may improve fertility in women with polycystic ovary syndrome (PCOS) by inducing or augmenting the ovulation cycle (41).

NAC has been shown to improve insulin sensitivity, restore normal menstrual cycles, normalize ovulatory cycles in women and improve fertility. It was also shown to work similarly to the conventional drug Metformin, which is impressive, as both treatments resulted in weight loss, a decrease in the excess body hair that often comes with PCOS, and improvements in cholesterol numbers (42).

Gut health

Chronic inflammation underlies a lot of intestinal tract conditions. NAC can assist us to root out pathogens, which are commonly discovered in the intestinal tract are often activates for Hashimoto’s indications.

NAC can similarly promote gastrointestinal system health by helping to detoxify gastrointestinal bacteria and breaking down biofilms. Biofilms are cumulative microorganisms that grow on the biological area and frequently house gut pathogens, which can, in turn, bring about infections.

The research study from 2014 found that in combination with different antibiotics, NAC can considerably permeate the inmost biofilm layers of bacteria that are winding up being considerably a lot more resistant to classic anti-bacterial therapies (43).

Helicobacter pylori are bacteria liable for stomach ulcers, and likewise, a possibly fatal bacterium carefully connected to malignant stomach cancer, the second most constant reason for cancer death worldwide.

NAC battles Helicobacter in a minimum of 2 ways. It significantly hinders the development of bacteria assisting to reduce the total load of microorganisms existing.72 NAC likewise strongly manages gene expression in stomach cells, reducing hydrogen peroxide production brought on by Helicobacter, and decreasing activation of NF-kB and subsequent release of inflammatory cytokines (44).

In human tests, NAC improves removal rates of Helicobacter produced by standard therapy with antacids and antibiotics, when used at dosages of 1,200 mg daily.

People that have gastritis or gastroesophageal reflux disease (GERD) might be infected with Helicobacter pylori and also may gain from supplementation with 1,200 mg each day of NAC, particularly throughout co-treatment with drugs to eliminate the microorganism (45).

Glutathione is a master antioxidant is the most-important redox regulator that controls inflammatory processes, and thus damages the periodontium.

NAC blocks pro-inflammatory cytokines and is of great importance in periodontal disease (46).

Heart disease

NAC may reduce heart disease risk by reducing oxidative damage to tissues in your heart from ROS production (47). 

  • Taking N-acetyl cysteine by mouth seems to reduce homocysteine levels, a possible risk factor for heart disease. B vitamins only somewhat help reduce high homocysteine. On the other hand, NAC can lower both homocysteine and high blood pressure, which helps prevent heart disease and other chronic health problems (48).

In two studies of 82 men, oral NAC lower homocysteine and blood pressure while increasing antioxidant status over 4 weeks. It had an equally beneficial effect in men with high and normal blood lipids, and in both smokers and non-smokers (49).


In another study of 60 people with heart disease, NAC lowered homocysteine levels and improved blood vessel health over 2 months (50).

  • It has also been shown to increase nitric oxide production, which helps veins dilate and improves blood flow. This expedites blood transit back to your heart and can lower your risk of heart attacks (51).

One test-tube study showed that when combined with green tea NAC appears to reduce damage from oxidized “bad” LDL cholesterol, another contributor to heart disease (52).

Ischemic stroke

Stroke is a leading cause of adult morbidity and mortality with very limited treatment options. Evidence from preclinical models of ischemic stroke has demonstrated that the antioxidant N-acetylcysteine (NAC) effectively protects the brain from ischemic injury (53).

A major study conducted in Germany in 2000 has shown that a combination of Millet Extract, Vitamin B5 (Pantothenic Acid), and the amino acid L-Cysteine can bring hair growth back to within normal rates (54).

My experience is that the hair benefits from NAC and looks healthier.

Immune function

N-acetylcysteine and glutathione boosts the immune health. 

This factor has been studied most in people with cysteine deficiency and T-cell dysfunction due to the human immunodeficiency virus (HIV).

Immune function might be improved — and potentially restored — by supplementing with NAC (55). In two studies, supplementing with NAC resulted in a significant increase in immune function — with an almost complete restoration of natural killer cells (56).

High levels of NAC in your body may also suppress HIV-1 reproduction (57).

Flu and flu-like symptoms

Taking NAC during the wintertime months might assist prevent and also treat flu-like signs. In one double-blind research study in 262 adults, 600 mg NAC two times a day was well endured and also resulted in a significant decline in the regularity of influenza-like episodes, intensity, and length of time confined to bed (58).

Some immunity to seasonal human influenza A viruses and also H5N1 (” bird”) influenza are seen in NAC usages. A test-tube study indicated that in immune-compromised situations, such as influenza, NAC might hinder the infection’s ability to replicate. This might reduce the signs and symptoms and lifespan of the disease (59).


Similarly, other test-tube studies have linked NAC to cancer cell death and blocked cancer cell replication (6061). Overall, more human studies are needed. Therefore, be sure to talk to your doctor before taking NAC during cancer treatment (62).

Joints disease

Rheumatoid arthritis (RA) is a common inflammatory disease of the joints. The aim of this study has been to evaluate the effects of oral NAC on inflammatory cytokines and oxidative stress in patients with RA.

Oral NAC can significantly reduce several oxidative stress factors and inflammatory cytokines (63).

Further, studies with a larger sample size, longer study duration, and higher doses of NAC are needed to confirm the effects of oral NAC in RA patients (64).

Kidney Cure

NAC plays an important role in your body’s detoxification process.

One interesting study emerges in 2017 about star fruit-induced acute kidney injury (AKI). Star fruit, or Averrhoa carambola, is a tropical fruiting tree in the oxalis family that’s native to tropical Asia (65).star fruit

Data show that therapeutic NAC attenuates renal dysfunction in a model of acute oxalate nephropathy following SF ingestion by reducing oxidative stress, oxaluria, and inflammation. This might represent a novel indication of NAC for the treatment of SF-induced AKI.

NAC can help prevent the side effects of drugs and environmental toxins (66).

Liver health

NAC boosts glutathione, the highest amount of which is in the liver.

This helps explain why NAC has such a strong effect on protecting the liver from inflammation, drug poisoning, and serious liver diseases.

If the liver is damaged, inflammation and oxidative stress always rise. NAC can protect the liver by reducing inflammation and increasing antioxidant reserves.

NAC reduced liver damage in 85% of all cases, according to a large review. It could protect the liver from factors such as excessive alcohol and environmental pollutants (67).

Interestingly, NAC injections helped increase liver function better than glutathione in one study of 75 patients with Hepatitis B (68).

Paracetamol liver damage

N-Acetyl Cysteine has been used as an antidote to acetaminophen poisoning for over 30 years.

Commonly-used painkillers (such as Tylenol) contain acetaminophen, which can damage the liver and even cause liver failure at high doses. Acetaminophen is the most common cause of serious, sudden, liver damage (69).

NAC can safely prevent serious liver damage from acetaminophen and increase survival, according to several studies of over 400 patients (7071).

Sudden, life-threatening liver damage can also be caused by various drugs, toxins, or hepatitis.

NAC helped protect the liver in 80 such cases. Patients with liver damage from drugs experienced the best results (72).

NAC has been studied a lot in intensive care units, as a possible way to reduce organ damage before and after surgery (73).

Hangover cure

NAC anti-oxidant benefits include liver-protective properties when exposed to alcohol. Just like in the acetaminophen toxicity treatment.

 A study on rats found that a NAC supplement taken 30 minutes before alcohol direct exposure seemed to produce a protective result while administration 4 hrs after alcohol direct exposure elevated organ tissue damage. Furthermore, these protective behaviors increased when alcohol consumption was stopped. 

Once again, it is very important to keep in mind that NAC ought to only be taken prior to intake of moderate quantities of alcohols.

NAC ought to never be taken after the usage of alcohol as it might have an opposite and harmful impact on the liver. 

This is essential to note as numerous hangover supplements, planned to be taken after the usage of alcoholic beverages, contain N-acetyl-L-cysteine.

The systemic lupus erythematosus (SLE), also known simply as lupus, is an autoimmune disease in which the body’s immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary between people and may be mild to severe. 

Common symptoms include painful and swollen joints, fever, chest pain, hair loss, mouth ulcers, swollen lymph nodes, feeling tired, and a red rash which is most commonly on the face. Often there are periods of illness, called flares, and periods of remission.

One study suggests the safe use of NAC for SLE.

This pilot study suggests that NAC safely improves lupus disease activity by blocking mTOR in T lymphocytes (74).

Muscle fatigue

In power training, NAC provides its antioxidant benefits directly within muscle cells.  Two of the benefits is to scavenge muscle-damaging free radicals and the body’s most critical antioxidants – glutathione.

According to research from Victoria University of Technology in Australia, it does that by increasing levels of cysteine within muscles, and because cysteine is required to restore glutathione to its active form, that should explain why NAC was shown to increase levels of activated glutathione before, during and after exercise.

Summary N-acetylcysteine supplementation increases exercise performance and reduce oxidative stress only in individuals with low levels of glutathione (75).

Reduce Exercise-Induced Oxidative Stress

We know that the fast boost in metabolic activity during exercise creates some undesirable negative effects.

These consist of an increase in oxidative stress that can overwhelm the body’s antioxidant defense reaction as well as lead to tissue damage and abnormal activity of specific immune system cells.

As a result of NAC’s capability to minimize oxidative stress and anxiety. It is possible that a reduction in the amount of oxidative stress a cell is subjected to could increase health as well as efficiency (76).

Photo by Edgar Chaparro on UnsplashIn an additional research study, acute supplementation of N-acetylcysteine does not influence muscle blood flow as well as oxygen distribution throughout handgrip exercise in males (77).

Muscle blood flow

Bodybuilders and also ‘fitness center rats’ love L-Cysteine. They would say that to gain more power, candid fatigue, construct muscle, gain toughness, strip off fat as well as keep much better health and wellness, take into consideration taking 600 to 2,400 milligrams of NAC each day.

You can take NAC before workouts with your pre-workout shake. On remainder days away from the fitness center, take it with your first meal of the day.

Patients suffering from chronic mountain sickness (CMS) have excessive erythrocytosis. Low-level cobalt toxicity as a likely contributor has been demonstrated in some subjects. NAC presents a helpful treatment for CMS.

hematocrit test measures how much of your blood is made up of red blood cells. Red blood cells contain a protein called hemoglobin that carries oxygen from your lungs to the rest of your body. 

One randomized, placebo-controlled clinical trial in Cerro de Pasco, Peru geronimo giqueaux 1422418 unsplash 1(4380 m), where 84 participants with a hematocrit (HCT) ≥65% and CMS score>6, were assigned to four treatment groups of a placebo, acetazolamide (ACZ, which stimulates respiration), N-acetylcysteine (NAC is a chelator of heavy metals) and combination of ACZ and NAC for 6 weeks. 

NAC improved CMS score compared to placebo, due to its chelation of heavy metals. NAC didn’t significantly lower hematocrit. Changes in other parameters failed to reach statistical significance. The combination of ACZ and NAC was no better than ACZ alone (78).

Neurodegenerative disorder

NAC’s ability to replenish glutathione and regulate brain glutamate levels can boost brain health. It may benefit especially those with brain and memory ailments (79).

SummaryThe brain neurotransmitter glutamate is involved in a broad range of learning, behavior and memory actions, while the antioxidant glutathione helps reduce oxidative damage to brain cells associated with aging (80).

The neurological disorder Alzheimer’s disease slows down a person’s learning and memory capacity. Animal studies suggest that NAC may slow the loss of cognitive ability in people with Alzheimer’s (81).

Another brain condition, Parkinson’s disease, is characterized by the deterioration of cells that generate the neurotransmitter dopamine. In a preliminary study from 2016, it was demonstrated for the first time a potential direct effect of NAC on the dopamine system in PD patients (82).

Both oxidative damage to cells and a reduction in antioxidant capability contribute to this disease.

NAC supplements appear to improve both dopamine function and disease symptoms such as tremors (83).

While NAC may improve brain health, more human research is needed to make strong conclusions.

NAC is described in a few trials in which its actions specifically on nail-biting and associated anxiety may offer a potential treatment. This anecdotal confession from WebMD helps to show the impact this self-treatment provides for nail-biting.

NAC has helped me to stop biting my fingernails. The compulsion to bite was drastically reduced almost as soon as I started taking it, and that was enough for me to stop biting completely. I started with 2000 mg once a day (as per the instructions on the packet) and have reduced that to 1200mg split into a morning and evening dose. I bought it in powder form (it is actually small crystals and not really a powder) and it took me a while to figure out how best to take it. The method that works for me is that I mix it in warm water and then add a dash of OJ. The warm water is so that it dissolves fully and the OJ is to avoid the unpleasant taste and the acidic aftertaste. At first I experienced heartburn if I took it on an empty stomach but that isn’t an issue any more – perhaps because of the reduced dose or the OJ. I am 42 years old and have been a nail-biter for as long as I can remember, so it is amazing to me that I have stopped thanks to a supplement. 

Obsessive-compulsive disorder

Considering the glutamate role, novel therapeutic strategies are suggested for OCD treatment. 

For people with bipolar disease and depression, NAC may help decrease symptoms and improve their overall ability to function. What’s more, research suggests that it may play a role in treating moderate to severe OCD (8485).

Psychiatric Disorders

Nearly all excitatory neurons in the  are glutamatergic, and it is estimated that over half of all brain synapses release this agent (86).

The novel clinical trials found that the regulation of glutamate, as well as replenishment of glutathione, may contribute to the improvement of mental health conditions, such as bipolar disorder, schizophrenia, obsessive-compulsive disorder (OCD), and addictive behavior (8788).Photo by Kat Jayne from Pexels

An animal study implied that NAC may minimize the negative effects of schizophrenia, such as social withdrawal, apathy, and reduced attention spans (89).

One of the most recent pilot studies tested the use of NAC as a potential treatment for Nonsuicidal self-injury (NSSI) in youth. Preliminary evidence said that NAC may have promise as a potential treatment option for this significant problem (90).

Respiratory Conditions

Image by Clker Free Vector Images from PixabayWhat are the benefits of NAC supplement for respiratory conditions? It has been used to improve COPD symptoms, exacerbations, and lung decline (919293).

Bronchitis occurs when the mucous membranes in your lungs’ bronchial passageways become inflamed, swell and shut off airways to your lungs (9495).

By thinning mucus in your bronchial tubes and boosting glutathione levels, NAC may help decrease the severity and frequency of wheezing, coughing and respiratory attacks (96).

In addition to relieving COPD and bronchitis, NAC may improve other lung and respiratory tract conditions like cystic fibrosis, asthma, and pulmonary fibrosis, as well as symptoms of nasal and sinus congestion due to allergies or infections (97).

Lung disease defense

NAC’s antioxidant and expectorant capacity can improve lung function by decreasing inflammation and reducing oxidative stress, as well as breaking up mucus.

Acute respiratory distress syndrome (ARDS) happens after an injury to the lungs and is life-threatening. Some studies suggest that intravenous NAC may boost levels of glutathione and help prevent and/or treat lung damage caused by ARDS. However, the results of other studies have been conflicting

Image by Benedict Rottmann from Pixabay

ARDS is a medical emergency. You should not try to treat it at home.

Smoke inhalation injury

One study with 90 consecutive pediatric patients between 1985 and 1995, who had bronchoscopically diagnosed inhalation injury, has reported that a combination of aerosolized heparin and a mucolytic agent, N-acetylcysteine, can ameliorate cast formation and reduce pulmonary failure secondary to smoke inhalation (98).

NAC increases blood levels of erythropoietin (EPO), a hormone produced by the kidney that promotes the formation of red blood cells by the bone marrow. 

NAC, in combination with large oral doses of folic acid and vitamin B12, may increase hemoglobin levels and bring mild cases of anemia into the normal range. Increasing hemoglobin levels also requires adequate production of testosterone and adequate amounts of iron (99).

A decrease in red blood cell (RBC) lipofuscin content has been seen, which is thought to be secondary to reducing lead toxicity and increasing antioxidative defenses (100).

One study declared that N-acetylcysteine improves the quality of red blood cells stored for transfusion (101).

Sleep apnea

Unfortunately, many of the obstructive sleep apnea (OSA) Photo by Alexandra Gorn on Unsplashpatients fail or are not candidates for nasal continuous positive airway pressure (CPAP) or surgical correction. 

The hypoxia and reoxygenation cycles in obstructive sleep apnea syndrome (OSAS) cause a change in the oxidative balance, leading to the formation of reactive oxygen species capable of reacting with other organic molecules impairing their functions.

Nitric oxide (NO) plays a critical role in controlling the vasomotor tone. The NO level depends on the L-arginine level, which can be decreased by arginase enzymatic activity. In one new study from 2018, the chronic intermittent hypoxia is reverted by the combined treatment with NAC and arginase inhibition supplementation (102).


There is a significant fall in glutathione peroxidase, glutathione reductase, reduced glutathione levels, and nitric oxide in the cells exposed to hypoxia. Significant elevation in the intracellular calcium level in the cells on exposure to hypoxia was observed. The study indicates that NAC has significant neuroprotective activity during hypoxia in primary hippocampal culture. (103).

In a placebo-controlled, randomized trial in 20 adults with obstructive sleep apnea, 600 mg of NAC was given three times daily for 30 days. The NAC group experienced multiple significant improvements in measurements of apnea severity and sleep quality.

  • NAC produced marked reductions in snoring and sleepiness 
  • The NAC showed significant reductions in oxidative stress 

Supplementation with NAC (50 microM) resulted in a significant cytoprotection, fall in ROS generation, and higher antioxidant levels similar to that of control cells. NAC also inhibited DNA strand breaks induced by hypoxia. The study indicates that NAC has significant neuroprotective activity during hypoxia in primary hippocampal culture.

NAC is a vitamin-like supplement and should be included in everydayPhoto by Emiliano Vittoriosi on Unsplash supplements for anti-aging because of the production of certain key antioxidants such as Glutathione. 

One study in Japan made of 10 healthy volunteers (6 males and 4 females, age range: 28 to 76 years) and 11 AD patients (6 males and 5 females, age range: 31 to 73 years) concluded that the topical application of NAC for 4 weeks increased skin hydration in 9/10 healthy volunteers (104). 

In a mouse model of AD, NAC was reported to restore the expression of some cell adhesion molecules that contribute to skin barrier formation by reducing oxidative stress… Thus, future studies involving a larger number of patients and excluding skin barrier-deteriorating factors are required to accurately assess the effects of NAC on AD.

Some anecdotal quotations of NAC benefits for skincare:

  • It makes the skin look healthy
  • It maintains the cellular health of the skin
  • It brightens the skin and gives it a naturally healthy glow
  • It makes the skin firmer
  • It clears acne
  • It reduces the appearance of age spots and even wrinkles. 

NAC, alpha-lipoic acid, and glutathione are all “sulfur donor supplements,” meaning their building blocks are sulfur-containing amino acids. In individuals whose bodies use up these amino acids too rapidly, as is the case when certain CBS variants are present, sulfur sensitivity can occur. Some people will have reactivity to NAC and the sulfur family of supplements.

Otherwise, sulfur-containing nutrients have many health benefits from maintaining healthy joints to boosting the immune system.


One study examined the efficacy of NAC as a glutamatergic agent in the treatment of trichotillomania. The results were favorable, as they have seen significant reductions in trichotillomania symptoms (105).

N-acetylcysteine, an amino acid, seems to restore the extracellular glutamate concentration in the nucleus accumbens and, therefore, offers promise in the reduction of compulsive behavior.

Pharmacologic modulation of the glutamate system may prove to be useful in the control of a range of compulsive behaviors.


One study shows a role for NAC in improving indomethacin-induced gastric ulceration in rats via antioxidative, antiapoptotic, and anti-inflammatory interactive mechanisms (106).

NAC also shows a potent gastro-protective effect in ethanol-induced gastric ulcers. This could be beneficial in gastric ulcer therapies. The researchers stated that molecular mechanisms behind such protection are complex (107).

Vitamin C and NAC synergy

An acute human inflammatory model strongly suggests that vitamin C and NAC supplementation immediately post-injury transiently increases tissue damage and oxidative stress (108).

N-acetylcysteine (NAC) has been used in clinical practice to treat critically ill septic patients, and more recently for COVID-19 patients. NAC has antioxidant, anti-inflammatory, and immune-modulating characteristics that may prove beneficial in the treatment and prevention of SARS-Cov-2. (109).

Weight loss

NAC’s ability to influence insulin level sensitivity might support weight-loss efforts because correct metabolism of insulin straight impacts the body’s ability to utilize fat for energy.

Photo by i yunmai on UnsplashAs sugar enters the bloodstream, insulin is released to restore blood sugar levels to normal. If the body doesn’t utilize insulin appropriately, it remains in the bloodstream.

High levels of insulin defeat weight-loss efforts since the hormone informs the body to maintain fat in storage.

Scientists at the Baylor University of Medicine located that low levels of glutathione weaken the capacity to break down fat. They decreased glutathione levels in young healthy mice as well as uncovered that the mice burned much less fat. When they offered glutathione to old mice that were lacking in the antioxidant, the pets were able to melt even more fat as well as reduce weight.

One research from 2016 made on rats found direct evidence of the protective potential of NAC against high-fat diet caused obesity and obesity-associated metabolic disorders (110).

Yeast infection

Yeast is microscopic fungi consisting of oval cells that reproduce by forming buds. There are many types of yeast. Some yeast types are important in baking and brewing (baker’s yeast, brewer’s yeast). Thus, most yeasts are harmless to humans. However, Candida albicans, or Candida, is a yeast that can infect humans and cause illness.

In one study on rats about baker’s-yeast induced fever and inflammation, the researchers found that NAC has an anti-inflammatory and antipyretic role in yeast-induced peritonitis (111).

Zinc depletion

Can N-Acetyl-L-cysteine affect zinc metabolism when used as a paracetamol antidote? Since we are at the end of this glossary list, we could ask about NAC side effects. 

One study also found that long-term use of high-dose NAC can deplete your body’s stores of zinc (112).

So if you are using NAC every day you should also supplement with zinc and low dose copper.

Standard Disclaimer:  The evidence for this supplement is based on a long clinical practice. But, still, this review is largely theoretical and anecdotal. Proceed at your own risk, preferably after reading the whole Longecity threadPlease check with your doctor before starting a new supplement regime, especially if you have any health conditions


For healthy and balanced individuals that have an optimized glutathione level the most logical suggestion is to cycle the NAC or otherwise not exaggerate it.

Balance is essential as too much of anything is never a good idea.

You can safely taste this not-so-delicious but very powerful antioxidant and nootropic! Enjoy it and tell us your experience.

Pick up nootropics that best reflect your goal

Read our next article to get you started

Best natural nootropics

Leave a Comment