N-Acetyl Cysteine (NAC) is a powerful antioxidant that works to protect the body against an array of oxidative stress issues including mood disorders, inflammation, infections, sleep, and much more (1).
In the body, NAC is transformed into cysteine. Cysteine is an amino acid that is important for regenerating another vital antioxidant, glutathione. However, NAC also acts to fight free radicals directly (2).
With around 1000 clinical trials, NAC is scientifically proven to prevent damage and inflammation, as well as protect the body and its tissues from harm. Other benefits include helping to produce other antioxidants, protecting the kidney and liver, reducing addictive behavior and the risk of certain psychiatric disorders, and much more (3).
1NAC contributes to the production of glutathione. Glutathione is considered one of the body’s most critical antioxidants. It acts on every cell in the body and is essential to optimal health and functioning (4).
In fact, researchers suggest that glutathione may even contribute to a longer life (5).
NAC, in combination with glutamine and glycine, helps the body make glutathione. Consequently, glutathione protects the body against age-related diseases, chronic inflammation, and other negative health effects (6).
2NAC can prevent kidney and liver damage. NAC works to increase glutathione. As well, it acts as an antioxidant on its own. These 2 factors help it prevent liver and kidney damage caused by excessive drinking or environmental factors (7).
NAC is already used to prevent kidney and liver damage in clinics and hospitals. Doctors administer it intravenously to patients along with acetaminophen (8).
In fact, NAC prevents acetaminophen poisoning, which can lead to liver failure or damage (9).
NAC has been studied extensively in preventing liver failure. A 2017 study proved yet again its use in reducing mortality rates amongst those with liver damage (10).
3NAC can decrease psychiatric disorders and may reduce addictive behavior. Glutamine plays a major role in the reward pathways associated with addiction. NAC, in particular cysteine, works to normalize glutamine levels, interrupting this cycle (11).
It is shown to help in marijuana addiction, cocaine addiction, and even in impulsive behaviors, such as hair pulling (12).
Excess glutamine is also associated with various psychiatric disorders, such as schizophrenia, OCD, depression, and bipolar conditions. Since cysteine works to balance out glutamine levels, it may decrease symptoms of these psychiatric disorders (13, 14).
4NAC improves the negative effects caused by respiratory conditions. It works to loosen mucus found in the air pathways and to decrease inflammation in the pulmonary system by reducing oxidative stress (15).
In a 2016 study, researchers explored the connection between NAC and COPD, Chronic Obstructive Pulmonary Disease. Patients were given 600 mg of NAC twice a day for 1 year. After 1 year, patients reported a reduction in their symptoms (16).
NAC was further found to reduce airway inflammation in cystic fibrosis patients after just 4 weeks (17).
5NAC may improve male and female fertility. Various studies have shown the use of NAC for male fertility. A 2016 study reported a 22% increase in partner pregnancy and semen quality with the administration of NAC post-surgery. Surgery was initially required to reduce free radical damage causing vein enlargement (18, 19).
In women, NAC was found to help those that suffer from polycystic ovary syndrome (PCOS). Patients with PCOS were instructed to take 1200 mg of NAC orally for 5 days. Researchers found that NAC significantly improved the ovulation rate, which in turn increased their chances of getting pregnant (20).
6NAC decreases the risk of heart disease. Heart disease is frequently caused by oxidative stress. Studies have reported the effectiveness of NAC in preventing heart disease by reducing this stress (21).
Another study explored NAC in relation to improved blood flow and vein dilation. It was shown to improve circulation and the efficiency of returning the blood to the heart. In turn, doctors and scientists claim that this can reduce the risk of a heart attack (22).
A 2016 study concluded that NAC improved fatigue, increased exercise tolerance, and reduced heart damage in rats (23).
Heart arrhythmia patients also showed improvements when taking NAC. These patients experienced reduced inflammation and oxidative stress, improving their overall condition (24).
7NAC can improve brain health and cognitive functioning. As aforementioned, NAC aids in regulating the neurotransmitter, glutamine. This neurotransmitter is associated with many cognitive processes, such as learning, memory, and behavior (25).
Through regulation of this neurotransmitter and the production of glutathione, NAC protects the brain from conditions such as Alzheimer’s Disease, Parkinson’s Disease, and ALS. It is further reported to improve mild cognitive impairments in older adults (26).
NAC may also play a role in reducing negative effects from traumatic brain injuries. In a 2013 study, patients reported a decrease in symptoms including dizziness, headaches, memory loss, and sleep disturbances (27).
8NAC may help stabilize blood sugar and help diabetic patients. NAC works to replenish antioxidant levels. It also reduces oxidative stress. Consequently, it can protect insulin receptors. This prevents the damage, destruction, and inflammation caused by diabetes (28, 29).
NAC may also play a role in stabilizing blood sugar by reducing inflammation in fat cells. Scientists believe that it may then improve an individual’s insulin resistance (30).
9NAC could help prevent the flu. During the flu season, germs run rampant. NAC may help protect the body against these germs and their effects. In one 1990s study, researchers gave the experimental group 600 mg, two times a day for 6 months. This group only contracted the flu 25% of the time. The control group, on the other hand, contracted the flu 79% of the time (31).
10NAC acts to protect the body from pollutants. NAC increases glutathione levels. As a result, the body is better prepared and protected against external toxins. Various studies suggest that NAC protects the body from heavy metal exposure, pesticides, diesel fuel, silica, chemical warfare, and deadly mushrooms (32, 33, 34, 35, 36, 37, 38, 39).
11NAC may help treat sleep apnea. A 2011 study explored NAC in relation to treatment for those suffering from sleep apnea. 20 patients received NAC for 30 days. Researchers concluded that oral administration of NAC may prove to be a viable treatment option for sleep apnea patients. It further may reduce sleep apnea patients’ reliance on continuous positive airway pressure (40).
12NAC could potentially help reduce acne. A 2012 study looked at 100 individuals suffering from acne. With the use of 5% NAC topical gel, participants noticed significant improvements and reduction in their acne symptoms (41).
13NAC may help combat negative side effects from chemotherapy. 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 (42).
In a 2014 study, NAC helped reduce inflammation and ulcers caused by chemotherapy in leukemia patients (43).
14NAC may help protect hearing and the ears. Again, researchers indicate that this may be attributed to NAC’s powerful antioxidant abilities.
A 2014 study explored NAC in relation to noise-induced hearing loss. The study was conducted using 48 participants who were exposed to continual noise during their working hours. 3 groups were observed. The first group was given 1200 mg of NAC per day. The second group was given 200 mg of ginseng per day.
And the third group had no supplementation assigned. After 14 days, researchers concluded that ginseng and NAC helped reduce hearing loss associated with occupational noise. However, the NAC group was shown to have the most positive effects (44).
1NAC can cause IBS like symptoms. High amounts may cause nausea, vomiting, diarrhea, and constipation (45).
2Aerosol NAC can cause swelling in the mouth, runny nose, drowsiness and chest tightness.
3NAC may interfere with blood clotting. Since NAC can impact the platelets and reduce coagulation, people with bleeding disorders or taking blood thinning medications should not take NAC (46).
4NAC can decrease blood pressure. Low blood pressure — also called hypotension — may cause symptoms of headache, dizziness or fatigue. If you feel dizzy, remain seated until this sensations passes to prevent further injury from falling down or tripping.
5NAC may cause an allergic reaction in certain individuals. A severe allergic reaction, called an anaphylactoid reaction, may occur after initial treatment with NAC supplements. An anaphylactoid reaction may result in severe breathing problems, difficulty swallowing, facial swelling, hives, weakness, dizziness or pale skin. Seek emergency medical care if you exhibit any of these symptoms after taking a NAC supplement.
However, it can go as high as 2400mg/day. The dosage is often split up into 2-3 doses.
Some studies the benefits of NAC for reducing addiction and mental health issues used doses closer to 3000 mg/day. For general wellness or gut health, 600 mg a day is the typical dose.
A maximum safe dose of NAC has yet to be determined.
What is N acetyl cysteine good for? As a prescription drug, doctors use NAC to treat acetaminophen overdose. It may also help break up mucus in people with some lung diseases, like chronic bronchitis. As a supplement, some people use NAC to try to protect the liver. There’s evidence it can help prevent bladder or neurologic damage caused by some drugs.
Is NAC safe to take daily? Yes, oral NAC supplements are safe and generally well tolerated.
Is N acetylcysteine over the counter? In addition to prescription availability, NAC is commercially accessible as an over-the-counter product and has been safely used as a supplement in humans for years (NAC is relatively rare in food).
What are the side effects of taking NAC? NAC is likely safe for adults when provided as a prescription medication. However, high amounts may cause nausea, vomiting, diarrhea, and constipation. When inhaled, it can cause swelling in the mouth, runny nose, drowsiness and chest tightness.
Should NAC be taken on an empty stomach? Yes, taking it on an empty stomach is ideal. 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.
Is NAC good for your liver? N-acetylcysteine is so protective to the liver that it is commonly administered to save patients who have overdosed on Tylenol from liver failure—it’s the only known antidote. NAC is a potent precursor of glutathione, a powerful antioxidant.
Can NAC help with high blood pressure? In animal studies of hypertension, NAC not only reduced blood pressure but also was effective at reducing oxidative stress and improving antioxidant capacity.
Is NAC good for chronic obstructive pulmonary disease (COPD)? Yes, NAC is an antioxidant supplement that has shown promise in some studies but not in others. NAC is a robust treatment for COPD that reduces phlegm and cough, thins mucus, and eases expectoration. It’s said to decrease the deterioration of lung function.
Does NAC lighten skin? Glutathione has been known to lighten the skin as since NAC is a precursor to glutathione, NAC can also be responsible for some skin lightening.
Does NAC increase glutathione? N-acetyl L-cysteine helps to replenish intracellular glutathione, a vital cellular antioxidant.
Does NAC help with weight loss? Not directly, however, NAC may play a role in the treatment of diabetes mellitus due to its ability to improve insulin sensitivity and reduce fasting blood insulin levels.
Does NAC help with hangovers? The best way to help prevent possible liver damage is to take an NAC hangover supplement before drinking alcohol (NAC and alcohol). This will assist in the production of glutathione which will help break down the toxic acetaldehyde.
NAC is an exceptional supplement, particularly for its ability to promote glutathione production within the body. It also has the capacity to rebalance the neurotransmitter, glutamine, which in excess contributes to an array of cognitive and mental impairments.
NAC also contributes to reduced oxidative stress and inflammation throughout the body. As a result, it protects the body against various ill health effects and diseases.
In addition, NAC may protect the body from external factors, such as pollutants, toxins, and germs, as well it may improve fertility in men and women. In other words, it helps the body function at its best.
According to most studies, the most common dosage of NAC falls between 800-2400 mg with a frequency of 2-3 times per day. However, it’s important to consult with your family doctor before taking any new medication. They know your medical history best and can make the proper recommendations for you and your specific situation.