Nutritional Supplement

N-Acetyl Cysteine

Also indexed as: Acetyl Cysteine, NAC

Where to Find It

Cysteine , the amino acid from which NAC is derived, is found in most high-protein foods. NAC is not found in the diet.

How to Use It

Healthy people do not need to supplement NAC. Optimal levels of supplementation remain unknown, though much of the research uses 250–1,500 mg per day.

References

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2. Boman G, Backer U, Larsson S, et al. Oral acetylcysteine reduces exacerbation rate in chronic bronchitis: report of a trial organized by the Swedish Society for Pulmonary Diseases. Eur J Respir Dis 1983;64:405–15.

3. Multicenter Study Group. Long-term oral acetylcysteine in chronic bronchitis. A double-blind controlled study. Eur J Respir Dis 1980;61:111:93–108.

4. Zheng JP, Wen FQ, Bai CX, et al. Twice daily N-acetyl cysteine 600 mg for exacerbations of chronic obstructive pulmonary disease (PANTHEON): a randomised, double-blind placebo-controlled trial. Lancet Respir Med 2014;2:187–94.

5. Tse HN, Raiteri L, Wong KY, et al. Benefits of high-dose N-acetylcysteine to exacerbation-prone patients with COPD. Chest. 2014;146:611–23.

6. Schermer T, Chavannes N, Dekhuijzen R, et al. Fluticasone and N-acetylcysteine in primary care patients with COPD or chronic bronchitis. Respir Med 2009;103:542–51.

7. Decramer M, Rutten-van Molken M, Dekhuijzen PN, et al. Effects of N-acetylcysteine on outcomes in chronic obstructive pulmonary disease (Bronchitis Randomized on NAC Cost-Utility Study, BRONCUS): a randomised placebo-controlled trial. Lancet 2005;365:1552–60.

8. Marchetti G, Lodola E, Licciardello L, Colombo A. Use of N-acetylcysteine in the management of coronary artery diseases. Cardiologia 1999;44:633-7.

9. Ardissino D, Merlini PA, Savonitto S, et al. Effect of transdermal nitroglycerin or N-acetylcysteine, or both, in the long-term treatment of unstable angina pectoris. J Am Coll Cardiol 1997;29:941-7.

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12. Houdijk AP, Van Leeuwen PA, Boermeester MA, et al. Glutamine-enriched enteral diet increases splanchnic blood flow in the rat. Am J Physiol 1994;267(6 Pt 1):G1035-40.

13. Wilmore DW, Smith RJ, O'Dwyer ST, et al. The gut: a central organ after surgical stress. Surgery 1988;104:917-23.

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15. Brzozowski T, Konturek SJ, Sliwowski Z, et al. Role of L-arginine, a substrate for nitric oxide-synthase, in gastroprotection and ulcer healing. J Gastroenterol 1997;32(4):442-52.

16. Stey C, Steurer J, Bachmann S, et al. The effect of oral N-acetylcysteine in chronic bronchitis: a quantitative systematic review. Eur Respir J 2000;16:253-62 [review].

17. Boman G, Backer U, Larsson S, et al. Oral acetylcysteine reduces exacerbation rate in chronic bronchitis: report of a trial organized by the Swedish Society for Pulmonary Diseases. Eur J Respir Dis 1983;64:405–15.

18. Riise GC, Larsson S, Larsson P, et al. The intrabronchial microbial flora in chronic bronchitis patients: a target for N-acetylcysteine therapy? Eur Respir J 1994;7:94-101.

19. Jackson IM, Barnes J, Cooksey P. Efficacy and tolerability of oral acetylcysteine (Fabrol) in chronic bronchitis: a double-blind placebo controlled study. J Int Med Res 1984;12:198-206.

20. Tattersall AB, Bridgman KM, Huitson A. Acetylcysteine (Fabrol) in chronic bronchitis—a study in general practice. J Int Med Res 1983;11:279-84.

21. Roederer M, Staal FJ, Raju PA, et al. Cytokine-stimulated human immunodeficiency virus replication is inhibited by N-acetyl-L-cysteine. Proc Natl Acad Sci 1990;87:4884-8.

22. Herzenberg LA, De Rosa SC, Dubs JG, et al. Glutathione deficiency is associated with impaired survival in HIV disease. Proc Natl Acad Sci 1997;94:1967-72.

23. Tewthanom K, Janwitayanujit S, Totemchockcyakarn K, et al. The effect of high dose of N-acetylcysteine in lupus nephritis: a case report and literature review. J Clin Pharm Ther 2010;35:483-5.

24. Hardan AY, Fung LK, Libove RA, et al. A randomized controlled pilot trial of oral N-acetylcysteine in children with autism. Biol Psychiatry 2012;71:956-61.

25. Nikoo M, Radnia H, Farokhnia M, et al. N-acetylcysteine as an adjunctive therapy to risperidone for treatment of irritability in autism: a randomized, double-blind, placebo-controlled clinical trial of efficacy and safety. Clin Neuropharmacol 2015;38:11–17.

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27. Berk M, Dean O, Cotton SM, et al. The efficacy of N-acetylcysteine as an adjunctive treatment in bipolar depression: an open label trial. J Affect Disord 2011;135:389-94.

28. De Quay B, Malinverni R, Lauterburg BH. Glutathione depletion in HIV-infected patients: role of cysteine deficiency and effect of oral N-acetylcysteine. AIDS 1992;6:815-9.

29. Tattersall AB, Bridgman KM, Huitson A. Acetylcysteine (Fabrol) in chronic bronchitis—a study in general practice. J Int Med Res 1983;11:279-84.

30. Kleinveld HA, Demacker PNM, Stalenhoef AFH. Failure of N-acetylcysteine to reduce low-density lipoprotein oxidizability in healthy subjects. Eur J Clin Pharmacol 1992;43:639-42.

31. Brumas V, Hacht B, Filella M, Berthon G. Can N-acetyl-L-cysteine affect zinc metabolism when used as a paracetamol antidote? Agents Actions 1992;36:278-88.

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The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2025.