NAC
What is NAC?
NAC is an amino acid that supports the immune system and respiratory health, assists our body in detoxification, and helps us withstand oxidative stress.
NAC stands for N-acetylcysteine. It is a particular chemical form of the amino acid cysteine which enables it to be better absorbed. Cysteine is the primary ingredient/amino acid used in the production of glutathione, our bodies’ main antioxidant.
NAC supports our immune systems and respiratory health, assists our body in detoxification and helps us withstand oxidative stress.
NAC is a mucolytic, meaning it helps to break up mucus so it can be more easily cleared from airways.[8]
Interestingly, NAC is also used as an antidote to prevent liver damage in those with paracetamol (acetaminophen) poisoning.[7]
The ability of supplemented NAC to actually increase glutathione levels in the body is dependent upon many things including genetics and availability of certain nutrients as co-factors. Thus, simply supplementing with NAC does not necessarily result in more glutathione.
Overall, the use of NAC for autism and psychiatric conditions is promising but requires more study. Supplementation with NAC is generally safe and well-tolerated.[8, 9]
Research has shown that NAC may be an effective preventative and therapeutic treatment against COVID-19 infection.[11-15]
Is NAC Beneficial in Autism?
Favorable evidence exists to support the use of NAC in several psychiatric and neurological disorders, particularly autism, Alzheimer's disease, cocaine and cannabis addiction, bipolar disorder, depression, trichotillomania, nail biting, skin picking, obsessive-compulsive disorder, schizophrenia, drug-induced neuropathy and progressive myoclonic epilepsy.[1]
N-acetylcysteine is safe and tolerable, reduces hyperactivity and irritability and enhances social awareness in children with autism spectrum disorder.[2]
The results of this trial indicate that NAC treatment was well tolerated, had the expected effect of boosting glutathione production, but had no significant impact on social impairment in youth with ASD.[5]
Those treated with NAC showed significantly reduced in irritability and hyperactivity/noncompliance scores.N-acetylcysteine can be considered as an adjuvant therapy for ADs with beneficial therapeutic outcomes.[6]
Antioxidant NAC, Irritability & repetitive behaviors
The antioxidant, N-Acetylcysteine or NAC, was supplemented to children with autism during a 12-week trial.
According to the Aberrant Behavior Checklist, NAC decreased the irritability score from 13.1 to 7.2. [16]
Additionally, children taking NAC showed a decrease in repetitive and stereotyped behaviors. [16]
*The NAC used was a pharmaceutical grade.
More research needs to be done to confirm these results.
NAC and Mood Disorders
Effects of N-acetylcysteine on obsessive-compulsive and related disorders, as well as on mood disorders, remain unclear with mixed reviews, even though promising evidence does exist. Oral N-acetylcysteine is safe and well tolerated without any considerable adverse effects. Current evidence supports its use as an adjunctive therapy clinically for psychiatric conditions, administered with existing medications, with a recommended dosage between 2000 and 2400 mg/day.[9]
Although preclinical studies have shown a positive effect of NAC on animal models of psychiatric disorders, including ADHD, anxiety, bipolar disorder, depression, OCD, PTSD and schizophrenia, the clinical efficacy of NAC is not fully established. NAC remains a strong candidate for adjunct treatment for many psychiatric disorders.[10]
Lack of Benefit with NAC for Autism?
This meta-analysis finds little support for the routine use of medications, including NAC, to treat restricted/repetitive behaviors in Autism Spectrum Disorder. [3]
This study failed to demonstrate any benefit of adjunctive N-acetyl cysteine in treating autistic disorder. While this may reflect a true null result, methodological issues particularly the lower dose (500 mg/day) utilised in this study may be confounders.[4]
Supplementation
NAC is available as a dietary supplement through professional-grade supplement dispensaries. Amazon retailers no longer carry NAC.
Examples of common NAC supplements include:
NAC is generally not available as a liquid, powder, tablet or chewable gummy.
DISCLAIMER: Before starting any supplement or medication, always consult with your healthcare provider to ensure it is a good fit for your child. Dosage can vary based on age, weight, gender, and current diet.
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[1] Deepmala J, Slattery N, Kumar L, et al. Clinical trials of N-acetylcysteine in psychiatry and neurology: A systematic review. Neurosci Biobehav Rev. 2015;55:294-321.
[2] Lee TM, Lee KM, Lee CY, Lee HC, Tam KW, Loh EW. Effectiveness of N-acetylcysteine in autism spectrum disorders: A meta-analysis of randomized controlled trials. Aust N Z J Psychiatry. 2021;55(2):196-206.
[3]Yu Y, Chaulagain A, Pedersen SA, et al. Pharmacotherapy of restricted/repetitive behavior in autism spectrum disorder:a systematic review and meta-analysis. BMC Psychiatry. 2020;20(1):121.
[4] Dean OM, Gray KM, Villagonzalo KA, et al. A randomised, double blind, placebo-controlled trial of a fixed dose of N-acetyl cysteine in children with autistic disorder. Aust N Z J Psychiatry. 2017;51(3):241-9.
[5] 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.
[6] Nikoo M, Radnia H, Farokhnia M, Mohammadi MR, Akhondzadeh S. 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(1):11-7.
[7] Emergency Care Institute (ECI). Paracetamol overdose. Gov.au. https://aci.health.nsw.gov.au/networks/eci/clinical/clinical-tools/toxicology/paracetamol. Published October 22, 2020. Accessed October 28, 2021.
[8] Šalamon Š, Kramar B, Marolt TP, Poljšak B, Milisav I. Medical and Dietary Uses of N-Acetylcysteine. Antioxidants (Basel). 2019;8(5):E111.
[9] Ooi SL, Green R, Pak SC. N-Acetylcysteine for the Treatment of Psychiatric Disorders: A Review of Current Evidence. Biomed Res Int. 2018;2018:2469486.
[10] Smaga I, Frankowska M, Filip M. N-acetylcysteine as a new prominent approach for treating psychiatric disorders. Br J Pharmacol. 2021;178(13):2569-94.
[11] Poe FL, Corn J. N-Acetylcysteine: A potential therapeutic agent for SARS-CoV-2. Med Hypotheses. 2020;143:109862.
[12] De Flora S, Balansky R, La Maestra S. Rationale for the use of N-acetylcysteine in both prevention and adjuvant therapy of COVID-19. FASEB J. 2020;34(10):13185-93.
[13] Zhou N, Yang X, Huang A, Chen Z. The Potential Mechanism of N-acetylcysteine in Treating COVID-19. Curr Pharm Biotechnol. 2021;22(12):1584-90.
[14] Ibrahim H, Perl A, Smith D, et al. Therapeutic blockade of inflammation in severe COVID-19 infection with intravenous N-acetylcysteine. Clin Immunol. 2020;219:108544.
[15] Andreou A, Trantza S, Filippou D, Sipsas N, Tsiodras S. COVID-19: The Potential Role of Copper and N-acetylcysteine (NAC) in a Combination of Candidate Antiviral Treatments Against SARS-CoV-2. In Vivo. 2020;34(3 Suppl):1567-88.
[16] News Center. Antioxidant shows promise as treatment for certain features of autism, study finds. https://med.stanford.edu/news/all-news/2012/05/antioxidant-shows-promise-as-treatment-for-certain-features-of-autism-study-finds.html.
