N-Acetylcysteine

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    Bill Willis, Katie Jantz

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    Nick Milazzo, Dmitri Barvinok
    Last Updated: June 12, 2024

    N-acetylcysteine (NAC) is a precursor for the amino acid L-cysteine. It has antioxidant, anti-inflammatory, and mucus thinning properties. NAC can act as a direct antioxidant, but more importantly, it provides the cysteine required for the production of glutathione, a powerful antioxidant produced in the body. NAC is commonly taken as a supplement for health and wellness and is used in clinical settings to treat drug overdose, cystic fibrosis, and chronic obstructive pulmonary disease.

    Overview

    Dosage information

    N-acetylcysteine can be given orally, intravenously, topically, or through inhalation.[1] Research suggests that in order to achieve the mucolytic effects in the respiratory tract, NAC needs to be administered through inhalation. Alternatively, oral or intravenous administration is the best way to benefit from NAC’s antioxidant effects.[2]

    The suggested dosage of NAC depends on what it’s being used for and the route through which it’s being administered. Orally, NAC is most often given in the dosage range of 600–1,800 mg daily (often divided into two or three daily doses), although higher doses are sometimes used in clinical research. Further research is needed to determine the optimal therapeutic dosages for other uses and methods.

    Frequently asked questions

    Update History

    Examine Database References

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    2. Mineral Bioaccumulation - Kasperczyk S, Dobrakowski M, Kasperczyk A, Ostałowska A, Birkner EThe administration of N-acetylcysteine reduces oxidative stress and regulates glutathione metabolism in the blood cells of workers exposed to leadClin Toxicol (Phila).(2013 Jul)
    3. Anaerobic Capacity - Cobley JN, McGlory C, Morton JP, Close GLN-Acetylcysteine Attenuates Fatigue Following Repeated-Bouts of Intermittent Exercise: Practical Implications for Tournament SituationsInt J Sport Nutr Exerc Metab.(2011 Aug 29)
    4. Trichotillomania Symptoms - Grant JE, Odlaug BL, Kim SWN-acetylcysteine, a glutamate modulator, in the treatment of trichotillomania: a double-blind, placebo-controlled studyArch Gen Psychiatry.(2009 Jul)
    5. COPD Symptoms - van Overveld FJ, Demkow U, Górecka D, de Backer WA, Zielinski JNew developments in the treatment of COPD: comparing the effects of inhaled corticosteroids and N-acetylcysteineJ Physiol Pharmacol.(2005 Sep)
    6. Neutrophil Activity - van Overveld FJ, Vermeire PA, De Backer WAInduced sputum of patients with chronic obstructive pulmonary disease (COPD) contains adhesion-promoting, therapy-sensitive factorsInflamm Res.(2000 Jan)
    7. OCD Symptoms - Afshar H, Roohafza H, Mohammad-Beigi H, Haghighi M, Jahangard L, Shokouh P, Sadeghi M, Hafezian HN-acetylcysteine add-on treatment in refractory obsessive-compulsive disorder: a randomized, double-blind, placebo-controlled trialJ Clin Psychopharmacol.(2012 Dec)
    8. COPD Symptoms - Jiang C, Zou J, Lv Q, Yang YSystematic review and meta-analysis of the efficacy of N-acetylcysteine in the treatment of acute exacerbation of chronic obstructive pulmonary disease.Ann Palliat Med.(2021-Jun)
    9. COPD Symptoms - Peter N Black, Althea Morgan-Day, Tracey E McMillan, Phillippa J Poole and Robert P YoungRandomised, controlled trial of N-acetylcysteine for treatment of acute exacerbations of chronic obstructive pulmonary diseasePulmonary Medicine.()
    10. COPD Symptoms - Decramer M, Rutten-van Mölken M, Dekhuijzen PN, Troosters T, van Herwaarden C, Pellegrino R, van Schayck CP, Olivieri D, Del Donno M, De Backer W, Lankhorst I, Ardia AEffects of N-acetylcysteine on outcomes in chronic obstructive pulmonary disease (Bronchitis Randomized on NAC Cost-Utility Study, BRONCUS): a randomised placebo-controlled trialLancet.(2005 Apr 30-May 6)
    11. COPD Symptoms - De Benedetto F, Aceto A, Dragani B, Spacone A, Formisano S, Pela R, Donner CF, Sanguinetti CMLong-term oral n-acetylcysteine reduces exhaled hydrogen peroxide in stable COPDPulm Pharmacol Ther.(2005)
    12. COPD Symptoms - Huang C, Kuo S, Lin L, Yang YThe efficacy of -acetylcysteine in chronic obstructive pulmonary disease patients: a meta-analysis.Ther Adv Respir Dis.(2023)
    13. Bronchitis Symptoms - Wei J, Pang CS, Han J, Yan HEffect of Orally Administered N-Acetylcysteine on Chronic Bronchitis: A Meta-analysis.Adv Ther.(2019-Dec)
    14. Irritability - Hardan AY, Fung LK, Libove RA, Obukhanych TV, Nair S, Herzenberg LA, Frazier TW, Tirouvanziam RA randomized controlled pilot trial of oral N-acetylcysteine in children with autismBiol Psychiatry.(2012 Jun 1)
    15. Irritability - Ghanizadeh A, Moghimi-Sarani EA randomized double blind placebo controlled clinical trial of N-Acetylcysteine added to risperidone for treating autistic disordersBMC Psychiatry.(2013 Jul 25)
    16. Urinary NOx - Dimitrios Tsikas, Jonas Niemann, Markus Flentje, Alexandra Schwarz, Paschalis TossiosN-Acetylcysteine (NAC) inhibits renal nitrite and nitrate reabsorption in healthy subjects and in patients undergoing cardiac surgery: risk of nitric oxide (NO) bioavailability loss by NAC?Int J Cardiol.(2014 Nov 15)
    17. Tobacco Addiction Symptoms - Knackstedt LA, LaRowe S, Mardikian P, Malcolm R, Upadhyaya H, Hedden S, Markou A, Kalivas PWThe role of cystine-glutamate exchange in nicotine dependence in rats and humansBiol Psychiatry.(2009 May 15)
    18. Marijuana Addiction - Gray KM, Watson NL, Carpenter MJ, Larowe SDN-acetylcysteine (NAC) in young marijuana users: an open-label pilot studyAm J Addict.(2010 Mar-Apr)
    19. Acne Symptoms - Ahmed Salih Sahib, Haidar Hamid Al-Anbari, Mohammed Salih, and Fatima AbdullahEffects of Oral Antioxidants on Lesion Counts Associated with Oxidative Stress and Inflammation in Patients with Papulopustular AcneJournal of Clinical and Experimental Dermatology Research .()
    20. Cocaine Addiction Symptoms - Duailibi MS, Cordeiro Q, Brietzke E, Ribeiro M, LaRowe S, Berk M, Trevizol APN-acetylcysteine in the treatment of craving in substance use disorders: Systematic review and meta-analysis.Am J Addict.(2017 Sep 12)
    21. Schizophrenia symptoms - Yolland CO, Hanratty D, Neill E, Rossell SL, Berk M, Dean OM, Castle DJ, Tan EJ, Phillipou A, Harris AW, Barreiros AR, Hansen A, Siskind DMeta-analysis of randomised controlled trials with -acetylcysteine in the treatment of schizophrenia.Aust N Z J Psychiatry.(2020-May)
    22. Kidney Function - Magner K, Ilin JV, Clark EG, Kong JWY, Davis A, Hiremath SMeta-analytic Techniques to Assess the Association Between N-acetylcysteine and Acute Kidney Injury After Contrast Administration: A Systematic Review and Meta-analysis.JAMA Netw Open.(2022-Jul-01)
    23. Helicobacter Pylori Infection Signs - Biswas DP, Tk DSThe efficacy of adjuvant N acetyl cysteine for the eradication of H pylori infections: A systematic review and meta-analysis of randomized clinical trials.Clin Res Hepatol Gastroenterol.(2022-Mar)
    24. Liver Enzymes - Jia D, Guo S, Jia Z, Gao Z, You K, Gong J, Li SN-acetylcysteine in the Donor, Recipient, or Both Donor and Recipient in Liver Transplantation: A Systematic Review With Meta-analysis and Trial Sequential Analysis.Transplantation.(2023-May-08)
    25. Length of hospitalization - Pereira JEG, El Dib R, Braz LG, Escudero J, Hayes J, Johnston BCN-acetylcysteine use among patients undergoing cardiac surgery: A systematic review and meta-analysis of randomized trials.PLoS One.(2019 May 9)
    26. Pain - Mohiuddin M, Pivetta B, Gilron I, Khan JSEfficacy and Safety of N-Acetylcysteine for the Management of Chronic Pain in Adults: A Systematic Review and Meta-Analysis.Pain Med.(2021-Dec-11)
    27. Testosterone - Zahra Shahveghar Asl, Karim Parastouei, Eslam EskandariThe effects of N-acetylcysteine on ovulation and sex hormones profile in women with polycystic ovary syndrome: a systematic review and meta-analysisBr J Nutr.(2023 Jan 4)
    28. Body Mass Index (BMI) - Liu J, Su H, Jin X, Wang L, Huang JThe effects of N-acetylcysteine supplement on metabolic parameters in women with polycystic ovary syndrome: a systematic review and meta-analysis.Front Nutr.(2023)
    29. Hearing Loss - Kranzer K, Elamin WF, Cox H, Seddon JA, Ford N, Drobniewski FA systematic review and meta-analysis of the efficacy and safety of N-acetylcysteine in preventing aminoglycoside-induced ototoxicity: implications for the treatment of multidrug-resistant TB.Thorax.(2015-Nov)
    30. Hearing Loss - Chang PH, Liu CW, Hung SH, Kang YNEffect of N-acetyl-cysteine in prevention of noise-induced hearing loss: a systematic review and meta-analysis of randomized controlled trials.Arch Med Sci.(2022)
    31. Hearing Loss - Bai X, Wang M, Niu X, Yu H, Yue JX, Sun YEffect of N-acetyl-cysteine treatment on sensorineural hearing loss: a meta-analysis.World J Otorhinolaryngol Head Neck Surg.(2022-Sep)
    32. All-Cause Mortality - Orban C, Agapie M, Bratu A, Jafal M, Duțu M, Popescu MNo Significant Beneficial Effects of Intravenous N-Acetylcysteine on Patient Outcome in Non-Paracetamol Acute Liver Failure: A Meta-Analysis of Randomized Controlled Trials.Biomedicines.(2024 Jul 1)