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N-Acetylcysteine

What is N-acetylcysteine?

N-acetylcysteine is a nonessential amino acid derivative, which can be produced in your body from the amino acid cysteine, so you do not need to get it from foods to be healthy ^[1].

N-Acetylcysteine Functions in the Human Body

N-acetylcysteine is ^[1]:

A nonproteinogenic amino acid, which is not regularly incorporated into proteins
A precursor of the antioxidant glutathione
A mucolytic–it makes mucus more liquid

N-Acetylcysteine Supplements

Nonprescription (over-the-counter):

N-acetylcysteine capsules and creams

By prescription:

Oral n-acetylcysteine (capsules)
N-acetylcysteine intravenous injections
N-acetylcysteine for inhalation

N-acetylcysteine Health Benefits

N-acetylcysteine supplements are EFFECTIVE in:

Acetaminophen (paracetamol) poisoning (as an oral drug or intravenous injection) ^[2,6,14]

N-acetylcysteine supplements are POSSIBLY EFFECTIVE in ^[2]:

Treatment of collapsed lungs–atelectasis ^[12,13,14]
Prevention of crusting after tracheostomy ^[2]
Lowering homocysteine levels (a possible risk factor for heart disease) ^{[25,26,27,28,29]}

There is CONFLICTING EVIDENCE about the effectiveness of N-acetylcysteine in the prevention of worsening of chronic bronchitis (chronic obstructive pulmonary disease) ^{[2,14,20,21,22,33]}.

N-acetylcysteine are POSSIBLY INEFFECTIVE ^[2] in the prevention or treatment of Alzheimer’s disease, amyotrophic lateral sclerosis (ALS, Lou Gehrig’s disease) ^[9], anxiety ^[9], bone loss in women after menopause, chronic kidney disease, head and neck tumors or lung cancer and viral hepatitis, HIV/AIDS, low blood pressure, pancreatitis, sensitivity to light in erythropoietic protoporphyria and side effects of doxorubicin (used for treating cancer), or in recovery after surgery.

There is INSUFFICIENT EVIDENCE ^[2] about N-acetylcysteine effectiveness in the prevention or treatment of acute respiratory distress syndrome (ARDS), alcoholic liver damage, altitude sickness, allergic reactions to phenytoin, Alzheimer’s disease ^[9], angina pectoris ^[16], asthma, attention deficit-hyperactive disorder (ADHD) ^[9], autism ^[9], bipolar disorder ^[9], carbon monoxide poisoning ^[14], cataracts, cerebral adrenoleukodystrophy, chronic fatigue syndrome (CFS), nicotine, cocaine or cannabis ^[8,9] or gambling addiction ^[9], colon cancer, cystic fibrosis ^[7], dental plaques, depression ^[9], diabetes mellitus type 2, dry eyes, ear infections, fertility, hair pulling and nail biting in psychiatric patients ^[3,9], hay fever, Helicobacter pylori infection of the stomach, hereditary hemorrhagic telangiectasia, HIV/AIDS, idiopathic pulmonary fibrosis ^[33], influenza (flu) ^[31,32,33], kidney problems with contrast dyes used during X-ray imaging ^[4,5,33], lamellar ichthyosis, liver cirrhosis, macular degeneration, malaria, mucus softening in various lung conditions (COPD) ^[10,11], multiple sclerosis ^[9], neuropathy ^[9], obsessive compulsive disorder (OCD) ^[9,23], polycystic ovarian syndrome (PCOS) ^[24], Parkinson’s disease ^[9], rheumatoid arthritis, schizophrenia ^[9], seizures (epilepsy) ^[9], septic shock, Sjögren’s syndrome, stroke ^[9] or ulcerative colitis, or in increasing tolerance to nitrates (drugs to treat ischemic heart disease) ^{[15,17,18,19]}, boosting immunity, stimulating hair growth, improving exercise performance, increasing HDL cholesterol, relieving side effects of ifosfamide (a drug used for treating cancer) ^[30], improving memory or removing mercury, lead and cadmium from the body.

N-acetylcysteine Safety: Side Effects, Toxicity

Prescribed N-acetylcysteine is LIKELY SAFE for most adults ^[2].

Side effects may include nausea, vomiting, diarrhea or constipation or, rarely, rashes, fever, headache, drowsiness, low blood pressure, and liver problems ^[2]. Allergy to N-acetylcysteine is possible.

Who should not take N-acetylcysteine?

Pregnant and breastfeeding women and individuals with asthma and cystinuria should avoid N-acetylcysteine ^[2]. Children should not take N-acetylcysteine without prescription.

N-acetylcysteine-Drug Interactions

N-acetylcysteine supplements may ^[2]:

Increase side effects of nitroglycerin (headache), increase the effect of ACE inhibitors (medications for high blood pressure), such as enalapril and captopril, and immunosuppressors, such as azathioprine and prednisone.

N-acetyl-L-cysteine PubChem
N-acetyl cysteine uses, side effects WebMD
Sansone RA et al, 2011, Getting a Knack for NAC PubMed Central
De Rosa SC et al, 2000, N-acetylcysteine replenishes glutathione in HIV infection PubMed
Pannu N, 2004, Systematic review of the impact of N-acetylcysteine on contrast nephropathy PubMed
Green JL et al, 2013, Oral and Intravenous Acetylcysteine for Treatment of Acetaminophen Toxicity: A Systematic Review and Meta-analysis PubMed Central
Duijvestijn YC et al, 1999, Systematic review of N-acetylcysteine in cystic fibrosis PubMed
Asevedo E et al, 2014, Systematic review of N-acetylcysteine in the treatment of addictions PubMed
Deepmala et al, 2015, Clinical trials of N-acetylcysteine in psychiatry and neurology: A systematic review ScienceDirect
Shen Y et al, 2014, Effect of high/low dose N-acetylcysteine on chronic obstructive pulmonary disease: a systematic review and meta-analysis PubMed
Sadowska AM et al, 2006, Role of N-acetylcysteine in the management of COPD PubMed Central
Mirhosseini JH et al, 2013, N-acetylcysteine instead of theophylline in patients with COPD who are candidates for elective off-pump CABG surgery: Is it possible in cardiovascular surgery unit? PubMed Central
Jepsen S et al, 1989, Peroral N-acetylcysteine as prophylaxis against bronchopulmonary complications of pulmonary surgery PubMed
N-Acetylcysteine – Medical Countermeasures Database CHEMM
Parker JO et al, 1987, Nitrate tolerance: the lack of effect of N-acetylcysteine PubMed
Chirkov YY et al, 1996, N-Acetylcysteine potentiates nitroglycerin-induced reversal of platelet aggregation PubMed
Hogan JC et al, 1990, Chronic administration of N-acetylcysteine fails to prevent nitrate tolerance in patients with stable angina pectoris PubMed
Ardissino D et al, 1997, Effect of Transdermal Nitroglycerin or N-Acetylcysteine, or Both, in the Long-Term Treatment of Unstable Angina Pectoris ScienceDirect
Maxwell SRJ et al, 1992, An update on nitrate tolerance: can it be avoided? PubMed Central
Stey C et al, 2000, The effect of oral N-acetylcysteine in chronic bronchitis: a quantitative systematic review PubMed
Dekhuijzen PNR et al, 2006, The role for N-acetylcysteine in the management of COPD PubMed Central
Aitio ML, 2006, N-acetylcysteine – passe-partout or much ado about nothing? PubMed Central
Oliver G et al, 2015, N-acetyl cysteine in the treatment of obsessive compulsive and related disorders: a systematic review PubMed
Thaker D et al, 2015, -Acetylcysteine for Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Clinical Trials PubMed Central
Bostom AG et al, 1996, Lack of effect of oral N-acetylcysteine on the acute dialysis-related lowering of total plasma homocysteine in hemodialysis patients PubMed
Thaha M et al, 2006, Intravenous N-acetylcysteine during haemodialysis reduces the plasma concentration of homocysteine in patients with end-stage renal disease PubMed
Miner SE et al, 2002, N-acetylcysteine neither lowers plasma homocysteine concentrations nor improves brachial artery endothelial function in cardiac transplant recipients PubMed
Friedman AN et al, 2003, The effect of N-acetylcysteine on plasma total homocysteine levels in hemodialysis: a randomized, controlled study PubMed
Yilmaz H et al, 2007, Effects of folic acid and N-acetylcysteine on plasma homocysteine levels and endothelial function in patients with coronary artery disease PubMed
Chen N et al, 2007, Prevention of ifosfamide nephrotoxicity by N-acetylcysteine: clinical pharmacokinetic considerations PubMed
De Flora S et al, 1997, Attenuation of influenza-like symptomatology and improvement of cell-mediated immunity with long-term N-acetylcysteine treatment PubMed
The Flu, the Common Cold, and Complementary Health Approaches National Center of Complementary and Integrative Health
Millea PJ et al, 2009, N-Acetylcysteine: Multiple Clinical Applications American Family Physician