N-acetyl cysteine comes from the amino acid L-cysteine. Amino acids are the building blocks of proteins. N-acetyl cysteine has many uses as medicine.
Supporting research & information
N-acetyl cysteine is used to counteract acetaminophen (Tylenol) and carbon monoxide poisoning. It is also used for chest pain (unstable angina), bile duct blockage in infants, amyotrophic lateral sclerosis (ALS, Lou Gehrig’s disease), Alzheimer’s disease, allergic reactions to the anti-seizure drug phenytoin (Dilantin), and an eye infection called keratoconjunctivitis. It is also used for reducing levels of a type of cholesterol called lipoprotein, homocysteine levels (a possible risk factor for heart disease) and the risk of heart attack and stroke in patients with serious kidney disease.
Some people use N-acetyl cysteine for chronic bronchitis, chronic obstructive pulmonary disease (COPD), hay fever, a lung condition called fibrosing alveolitis, head and neck cancer, and lung cancer. It is also used for treating some forms of epilepsy; ear infections; complications of kidney dialysis; chronic fatigue syndrome (CFS); an autoimmune disorder called Sjogren’s syndrome; preventing sports injury complications; radiation treatment; increasing immunity to flu and H1N1 (swine) flu; and for detoxifying heavy metals such as mercury, lead, and cadmium.
N-acetyl cysteine is also used for preventing alcoholic liver damage; for protecting against environmental pollutants including carbon monoxide, chloroform, urethanes and certain herbicides; for reducing toxicity of ifosfamide and doxorubicin, drugs that are used for cancer treatment; as a hangover remedy; for preventing kidney damage due to certain X-ray dyes; and for human immunodeficiency virus (HIV).
Healthcare providers give N-acetyl cysteine intravenously (by IV) for acetaminophen overdose, acrylonitrile poisoning, amyotrophic lateral sclerosis (ALS, Lou Gehrig’s disease), kidney failure in the presence of liver disease (hepatorenal syndrome), chest pain in combination with nitroglycerin, heart attack in combination with nitroglycerin and streptokinase, and for helping to prevent multi-organ failure leading to death.
N-acetyl cysteine is sometimes inhaled (breathed into the lungs) or delivered through a tube in the throat to treat certain lung disorders such as pneumonia, bronchitis, emphysema, cystic fibrosis, and others.
How does it work?
N-acetyl cysteine treats acetaminophen (Tylenol) poisoning by binding the poisonous forms of acetaminophen that are formed in the liver. It is also an antioxidant, so it may play a role in preventing cancer.
- Acetaminophen (Tylenol) poisoning. N-acetyl cysteine is effective in reducing the death rate and preventing the permanent harm caused by acetaminophen poisoning. For this use, N-acetyl cysteine given by mouth is as effective as N-acetyl cysteine given intravenously (by IV).
- Collapse of part or all of a lung (atelectasis). N-acetyl cysteine helps treat collapsed lungs caused by mucus blockage.
- Diagnostic lung tests. N-acetyl cysteine is helpful when used to prepare people for diagnostic lung tests.
- Care of people with a tube in their windpipe (people who have undergone a tracheostomy). N-acetyl cysteine helps prevent crusting in people with a tube in their windpipe.
Possibly Effective for:
- Chest pain (angina). Taking N-acetyl cysteine by mouth or injecting it intravenously (by IV) seems to improve chest pain when used with the drug nitroglycerin. Intravenous N-acetyl cysteine seems to help prevent nitroglycerin tolerance. Oral N-acetyl cysteine might help prevent nitroglycerin tolerance, but results are conflicting.
- Bipolar disorder. Taking N-acetyl cysteine by mouth seems to help reduce depression symptoms in people with bipolar disorder.
- Air passage swelling (bronchitis). Taking N-acetyl cysteine by mouth seems to reduce shortness of breath in people with air passage swelling due to mustard gas exposure. Also, taking N-acetyl cysteine by mouth for 3-6 months seems to prevent flare-ups in people with persistent air passage swelling. However, taking it for less time does not seem to be effective.
- A lung disease called chronic obstructive pulmonary disease (COPD). Taking N-acetyl cysteine by mouth seems to decrease flare-ups by about 40% and improve sputum (phlegm) consistency in people with COPD. However, it might increase the risk of blockage of the breathing tube.
- Kidney problems caused by dyes used during some X-ray exams. Taking N-acetyl cysteine by mouth seems to help prevent kidney problems caused by dyes used during some X-ray exams in people with severely reduced kidney function (kidney insufficiency). It might help prevent these problems in people with moderately reduced kidney function. It does not seem to lower the risk of kidney problems caused by dyes used during X-ray exams in people with normal kidney function.
- Serious kidney disease. Taking N-acetyl cysteine by mouth seems to help prevent problems, such as heart attack and stroke, in people with serious kidney disease. The risk reduction can be as much as 40%. However, N-acetyl cysteine doesn’t reduce the overall risk of death or the risk of death from heart disease in these people.
- Epilepsy seizures. Taking N-acetyl cysteine by mouth seems to help treat a certain type of epilepsy seizure.
- A lung disease called fibrosing alveolitis. Taking N-acetyl cysteine by mouth seems to improve lung function in people with fibrosing alveolitis.
- High levels of homocysteine. Taking N-acetyl cysteine by mouth seems to reduce homocysteine levels, a possible risk factor for heart disease.
- High levels of blood fat. Taking N-acetyl cysteine by mouth seems to reduce levels of a blood fat called lipoprotein(a) in people with high levels of this blood fat at baseline.
- Ifosfamide (Ifex) side effects. Taking N-acetyl cysteine by mouth seems to help prevent side effects of ifosfamide (Ifex), which is used for certain types of cancer. However the drug mesna (Mesnex) seems to work better than N-acetyl cysteine.
- Flu. Taking N-acetyl cysteine by mouth seems to reduce flu symptoms.
- Heart attack. Injecting N-acetyl cysteine intravenously (by IV) seems to help maintain heart function in people having a heart attack when given with the drugs nitroglycerin and streptokinase.
- Tolerance to nitrate. Injecting N-acetyl cysteine intravenously (by IV) seems to help prevent tolerance to nitrate. Oral N-acetyl cysteine might help prevent nitrate tolerance, but results are conflicting.
- Hair pulling. Taking N-acetyl cysteine by mouth seems to decrease hair pulling by up to 40%.
N-acetyl cysteine is LIKELY SAFE for most adults, when used as a prescription medication. It can cause nausea, vomiting, and diarrhea or constipation. Rarely, it can cause rashes, fever, headache, drowsiness, low blood pressure, and liver problems. When inhaled (breathed into the lungs), it can also cause swelling in the mouth, runny nose, drowsiness, clamminess, and chest tightness.
N-acetyl cysteine has an unpleasant odor that may make it hard to take.
Special Precautions & Warnings:
- Pregnancy or breast-feeding: N-acetyl cysteine is POSSIBLY SAFE when taken by mouth, delivered through a hole in the windpipe, or breathed in. N-acetyl cysteine crosses the placenta, but there is no evidence so far linking it with harm to the unborn child or mother. However, N-acetyl cysteine should only be used in pregnant women when clearly needed, such as in cases of acetaminophen toxicity. There is not enough reliable information about the safety of taking N-acetyl cysteine if you are breast-feeding. Stay on the safe side and avoid use.
- Allergy: Don’t use N-acetyl cysteine if you are allergic to acetyl cysteine.
- Asthma: There is a concern that N-acetyl cysteine might cause bronchospasm in people with asthma if inhaled or taken by mouth or through a tube in the windpipe. If you take N-acetyl cysteine and have asthma, you should be monitored by your healthcare provider.
- Bleeding disorder. N-acetyl cysteine might slow blood clotting. There is concern that N-acetyl cysteine might increase the risk of bruising and bleeding in people with bleeding disorders.
- Surgery. N-acetyl cysteine might slow blood clotting. This might increase the risk of bleeding during and after surgery. Stop taking N-acetyl cysteine at least 2 weeks before a scheduled surgery.
Interactions with other drugs and medications:
Major Interaction Do not take this combination:
Nitroglycerin interacts with N-ACETYL CYSTEINE: Nitroglycerin can dilate blood vessels and increase blood flow. Taking N-acetyl cysteine seems to increase the effects of nitroglycerin. This could cause increased chance of side effects including headache, dizziness, and lightheadedness.
Moderate Interaction Be cautious with this combination
Activated charcoal interacts with N-ACETYL CYSTEINE
Activated charcoal is sometimes used to prevent poisoning in people who take too much acetaminophen and other medications. Activated charcoal can bind up these medications in the stomach and prevent them from being absorbed by the body. Taking N-acetyl cysteine at the same time as activated charcoal might decrease how well it works for preventing poisoning.
NAC as a supplement has many uses and can help people with a diverse set of issues, including mood disorders, brain issues, lung problems, sleep disorders, infections, and in states of oxidative stress. It can even help protect you from the flu. Here we list 28 health benefits of N-Acetyl Cysteine as well as the possible side effects of taking it.
N-Acetyl Cysteine, also known as NAC, is an altered version of Cysteine. Cysteine is an amino acid containing sulfur.
NAC is essential in replenishing and maintaining Glutathione levels in the body [R]. Glutathione is an antioxidant that removes oxygen radicals from cells [R].
The removal of these reactive species is important because they will cause cellular and tissue damage if they are allowed to remain in cells. NAC has also been found to reduce inflammation in tissues [R].
NAC not only can be ingested into the body orally but also through inhalation. As seen below, the supplement can be used for many different purposes.
Health Benefits of N-Acetyl Cysteine
NAC Can Help Alzheimer’s and Parkinson’s
Alzheimer’s is a neurological disorder that slows down subjects’ learning and memory abilities.
Studies have shown that NAC may work to slow or negate the loss of cognitive ability in mouse models of Alzheimer’s [R].
Patients with Parkinson’s disease who supplement with NAC experience notable improvements in dopamine function and symptoms.
11) NAC Can Help Negate the Effects 0f Schizophrenia
Schizophrenia is characterized by failure to understand reality and abnormal social behaviors.
NAC can work to possibly minimize negative effects of schizophrenia [R].
A primate-specific gene locus G72 is linked to the development of these diseases by enlarging synapses in the brain.
When mice were treated with NAC, their synapses were normalized, indicating that NAC can play a part in helping with mental illnesses [R].
12) NAC Can Prevent Addictive Behaviors
Addictive behaviors include binge eating, drug addictions, and other compulsive behaviors. NAC can reduce or eliminate these behaviors in rodent models [R].
A systematic review found that NAC helps people with addictions, especially cocaine and cannabis. Behaviors such as hair pulling or nail biting can also be prevented using NAC [R].
The effects were mediated by normalizing the excitatory neurotransmitter glutamate [R].
13) NAC Can Prevent Depression and Bipolar Disorder
Depression and bipolar disorder are severe conditions that are becoming more prevalent in our world today.
Symptoms caused by these disorders can be significantly improved by taking NAC. NAC can also help in improving people’s ability to function while experiencing these symptoms [R].
14) NAC Can Prevent Obsessive Compulsive Disorder (OCD)
OCD causes social anxiety and compulsive behaviors. NAC can help with treatment in severe cases of OCD [R].
15) NAC Can be a Treatment for SleepDisorders
NAC could help treat patients suffering from obstructive sleep apnea, a disorder where a person’s breathing repeatedly stops and starts during sleep.
Patients who took daily doses of NAC had improved sleep efficiency and snored less than those who took a placebo (RCT).
Oral NAC administration appears to be a potential treatment for sleep apnea [R].