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Nutritional Supplement

N-Acetyl Cysteine

  • Heart and Circulatory Health

    Chronic Obstructive Pulmonary Disease

    N-acetyl cysteine helps break down mucus and supplies antioxidant protection to lung tissue.
    Chronic Obstructive Pulmonary Disease
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    NAC (N-acetyl cysteine) helps break down mucus. For that reason, inhaled NAC is used in hospitals to treat bronchitis. NAC may also protect lung tissue through its antioxidant activity.1 Oral NAC, 200 mg taken three times per day, is also effective and improved symptoms in people with bronchitis in double-blind research.2,3 In other double-blind studies, oral NAC in the amount of 600 mg twice a day for 1 year significantly decreased the number of disease exacerbations in patients with moderate-to-severe COPD.4,5 However, NAC was ineffective in one study.6 Results may take six months. NAC does not appear to be effective for people with COPD who are taking inhaled steroid medications.7

    Angina

    Under a doctor’s supervision, supplementing with NAC may improve the effects of nitroglycerin.
    Angina
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    NAC (N-acetyl cysteine) may improve the effects of nitroglycerin in people with angina.8 People with unstable angina who took 600 mg of NAC three times daily in combination with a nitroglycerin transdermal (skin) patch for four months had significantly lower rates of subsequent heart attacks than did people who used either therapy alone or placebo.9

    Heart Attack

    In one study, NAC injections decreased the amount of tissue damage in people who had suffered a heart attack.
    Heart Attack
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    In one study, intravenous injections of NAC (N-acetyl cysteine) decreased the amount of tissue damage in people who had suffered a heart attack.[REF] Whether oral NAC would have the same effect is unknown.
  • Digestive Support

    Gastritis

    In one study, people with atrophic gastritis given NAC saw increased healing.
    Gastritis
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    Various amino acids have shown promise for people with gastritis. In a double-blind trial, taking 200 mg of cysteine four times daily provided significant benefit for people with bleeding gastritis caused by NSAIDs (such as aspirin).10 Cysteine is a sulfur-containing amino acid that stimulates healing of gastritis. In a preliminary trial, 1–4 grams per day of NAC (N-acetyl cysteine) given to people with atrophic gastritis for four weeks appeared to increase healing.11Glutamine, another amino acid is a main energy source for cells in the stomach and supplementation may increase blood flow to this region.12 Patients in surgical intensive care units often develop gastrointestinal problems related to a glutamine deficiency.13 When burn victims were supplemented with glutamine, they did not develop stress ulcers, even after several operations.14 Nevertheless, it remains unclear to what extent glutamine supplementation might prevent or help existing gastritis. Preliminary evidence suggests the amino acid arginine may both protect the stomach and increase its blood flow,15 but research has yet to investigate the effects of arginine supplementation in people with gastritis.

  • Immune System Support

    Bronchitis

    NAC, which appears to work by reducing the thickness of mucus, has been shown to be a safe and effective treatment for chronic bronchitis.
    Bronchitis
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    A review of 39 clinical trials of NAC (N-acetyl cysteine) found that 400 to 600 mg per day was a safe and effective treatment for chronic bronchitis.16 NAC supplementation was found to reduce the number of aggravations of the illness in almost 50% of people taking the supplement, compared with only 31% of those taking placebo. Smokers have also been found to benefit from taking NAC.17 In addition to helping break up mucus, NAC may reduce the elevated bacterial counts that are often seen in the lungs of smokers with chronic bronchitis.18 In another double-blind study, people with chronic bronchitis who took NAC showed an improved ability to expectorate and a reduction in cough severity.19 These benefits may result from NAC’s capacity to reduce the viscosity (thickness) of sputum.20

    HIV and AIDS Support

    Supplementing with NAC may slow the decline in immune function.
    HIV and AIDS Support
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    The amino acid NAC (N-acetyl cysteine) has been shown to inhibit the replication of HIV in test tube studies.21 In a double-blind trial, supplementing with 800 mg per day of NAC slowed the rate of decline in immune function in people with HIV infection. NAC also promotes the synthesis of glutathione, a naturally-occurring antioxidant that is believed to be protective in people with HIV infection and AIDS.22

    Lupus

    In a case report, a woman with kidney disease due to SLE (lupus nephritis) may have had an improvement in her kidney function due to treatment with N-acetylcysteine (NAC).
    Lupus
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    In a case report, a woman with kidney disease due to SLE (lupus nephritis) had an improvement in her kidney function and was able to taper off of her steroid medicine after starting treatment with N-acetylcysteine (NAC) in the amount of 600 mg 3 times per day. She continued NAC, and after a total of 13 months her disease was considered inactive.23
  • Children's Health

    Autism

    A double-blind study found that supplementing with NAC for 12 weeks improved symptoms of irritability in children with autism.
    Autism
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    In a double-blind trial, supplementation with N-acetylcysteine (NAC) for 12 weeks improved symptoms of irritability in children with autism.24 The amount of NAC used in the study was 900 mg per day for four weeks, then 900 mg twice a day for four weeks, then 900 mg three times per day for four weeks. Another double-blind study found an improvement in irritability using smaller amounts of NAC: 600 mg per day for children weighing less than 44 pounds and 900 mg per day for children weighing 44 pounds or more.25 However, in a third double-blind trial, NAC in an average amount of 56 mg per 2.2 pounds of body weight per day for 12 weeks was of no benefit in autistic children.26 Because the amounts of NAC used in these studies are relatively large and the long-term safety of this treatment has not been examined, NAC treatment of autistic children should be monitored by a doctor.
  • Brain Health

    Bipolar Disorder

    In a preliminary trial, depression in patients with bipolar disorder significantly improved after NAC treatment.
    Bipolar Disorder
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    In a preliminary trial, depression in patients with bipolar disorder significantly improved after N-acetyl cysteine treatment (1,000 mg twice a day for eight weeks).27 Double-blind trials are needed to confirm this benefit.
What Are Star Ratings?
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Reliable and relatively consistent scientific data showing a substantial health benefit.
Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.

For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

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References

1. Van Schayck CP, Dekhuijzen PN, Gorgels WJ, et al. Are anti-oxidant and anti-inflammatory treatments effective in different subgroups of COPD? A hypothesis. Respir Med 1998;92:1259–64.

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.

10. Salim AS. Sulfhydryl-containing agents in the treatment of gastric bleeding induced by non-steroidal anti-inflammatory drugs. Can J Surg 1993;36(1):53-8.

11. Farinati F, Cardin R, Della Libera G, et al. Effects of N-acetyl-L-cysteine in patients with chronic atrophic gastritis and nonulcer dyspepsia: a phase III pilot study. Curr Ther Res 1997;58:724-33.

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.

14. Yan R, Sun Y, Sun R. Early enteral feeding and supplement of glutamine prevent occurrence of stress ulcer following severe thermal injury. Chung Hua Cheng Hsing Shao Shang Wai Ko Tsa Chih 1995;11(3):189-92.

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.

26. Wink LK, Adams R, Wang Z, et al. A randomized placebo-controlled pilot study of N-acetylcysteine in youth with autism spectrum disorder. Mol Autism 2016;7:26.

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.

Copyright © 2020 TraceGains, Inc. All rights reserved.

Learn more about TraceGains, the company.

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 2020.

Copyright © 2020 TraceGains, Inc. All rights reserved.

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. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. 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 2020.