10 Ways NAC Can Help You Thrive

by in Blog January 8, 2023

I always tell my clients that the great thing about supplements vs medications is that instead of side effects, there’s side benefits. The truth of this saying is abundantly clear when examining the actions of N-acetylcysteine on health. NAC is an antioxidant that provides a plethora of benefits, including detoxification, neutralization of harmful microbes, and hormonal support. If you’re interested in boosting your body’s detox and immune power (especially during flu and allergy seasons), keep reading for 10 reasons why NAC should be one of your top supplements! (or skip to the summary at the end if you like spoilers)

1. NAC Supports Detoxification

Our body’s most important detox organ is the liver. Glutathione is the main detoxification (and antioxidant) enzyme in the liver and throughout the body. It is responsible for most of the body’s transformation of chemicals, such as medications and toxins, into substances that can be eliminated. The main substance shown to increase the body’s production of glutathione is NAC!

For example, in a 2 month study of malnourished children, those given NAC saw glutathione levels increase 150% and production by 510%, while no increase was observed in the control group. (1) In a clinical trial of diabetic adults, NAC supplementation led to a 194% increase in glutathione production in just 2 weeks, which led to improvements in several other health markers. (2)

NAC’s beneficial effect on glutathione also protects the liver from damage so it can function better to support detoxification. A study of acute liver failure patients highlights how influential NAC can be on liver function. Researchers found that with supplementation, 72.5% survived, compared to only 47.5% in the control group. The NAC group also spent on average 8 days in the hospital, compared to 10.5 days. (3)

Glutathione is not only increased in the liver, but also in the brain. Thus, NAC can serve a neuroprotective role, detoxing the brain to improve diseases such as Parkinson’s and Alzheimer’s. (4)

As a result, this powerful nutrient can decrease our body’s toxic burden by helping to increase elimination of harmful substances such as heavy metals and mold. (5) It’s so effective in supporting the liver that the standard hospital protocol for overdose of acetaminophen (Tylenol) is to give high dose NAC. A large review of all the research showed those given NAC had a 74% reduced risk of mortality from liver failure due to overdose. (6)

2. NAC is a Powerful Decongestant

Whether you have a cold in the fall or allergies in the spring, NAC has got your back! It can help your sinuses by decreasing mucus production, restoring your body’s mucus clearance, and even regulating inflammatory proteins. (7)

Since mucus production greatly affects the efficiency of the lungs, NAC also supports your lungs in various ways. It can reduce COPD exacerbations and improve lung function in cystic fibrosis patients. (8) NAC can also significantly alleviate bronchitis and asthma flare-ups. This is not only because of its mucus regulating properties, but also because it can prevent the accumulation of inflammatory cells in the respiratory tract. (9, 10)

An additional bonus: it may be able to help protect you from serious acute respiratory distress syndrome (ARDS). For example, one study supplemented ARDS patients with NAC and found that glutathione increased by 47%, days sick decreased, and cardiac markers improved. (11)

3. Supports the Immune System

NAC works to support the immune system through its powerful antioxidant properties and control of inflammatory compounds. One study was interested in NAC’s ability to reduce symptoms of the flu. 262 participants were either supplemented with NAC or a placebo for 6 months during flu season. 79% of the virus infected patients in the placebo group developed symptoms of the flu compared to 25% in the NAC group! They also found that the infected individuals in the NAC group spent much less time in bed compared to their placebo counterparts. (12)

Clearly, NAC is a useful tool in your toolkit for illness prevention. This is partly because it can obstruct the attachment of harmful microbes to our tissue. NAC makes it harder for influenza (the cause of the flu), strep, and Moraxella (one of the main causes of ear, sinus, and respiratory infections) to live and thrive in our bodies. (13, 14) Even in the treatment of COVID-19, researchers have found it can improve symptoms and lab markers, reduce risk of severe infection, increase oxygenation, and reduce hospital stays! (15)

4. NAC Addresses Hormonal Issues


As if the many wondrous effects of NAC wasn’t already impressive enough, it also contributes to women’s hormone health. For example, a systematic review of the research found that women with PCOS were 3.5 times more likely to have a pregnancy after NAC supplementation. Not only that, but their odds of a live birth were 3 times higher compared to their counterparts who received a placebo. (16)

NAC also supports fertility in those who don’t have PCOS. It can significantly increase the number of ovarian follicles in women with unexplained infertility. As a result, a study found that 35% of women taking NAC were able to get pregnant vs 8.5% in the placebo group. (17) While a large review of 15 studies revealed that some women didn’t find benefits, when all the results were pooled, there was an average 55% increase in pregnancy rate compared to the control group, a 77% improvement in ovulation, and a 24% decrease in miscarriage. (18)


NAC also has benefits for women’s health outside of fertility. Endometriosis is an estrogen-dominant, painful condition negatively affected by inflammation. Thanks to the antioxidant, anti-inflammatory, and decongestant properties of NAC, studies show it can be tremendously helpful for endometriosis. It can decrease excessive growth of endometrial tissue, decrease pain, and prevent recurrence (19). In fact, in a study of patients scheduled for surgery to remove endometriosis tissue, 24 of 47 patients receiving 1,800mg NAC cancelled their surgery due to improvement in ultrasound findings and pain, versus only 1 of 45 in the control group! (20)

5. NAC is Helpful for Histamine Conditions

The research on NAC supplementation and histamine is still preliminary, having been done in cell cultures rather than living humans. One study suggests it blocks the enzyme that makes histamine. (21) Another showed that adding NAC makes antihistamine drugs more effective. (22) A third one found no change in histamine levels. (23)

However, it’s worth considering because NAC has been shown to be effective in improving symptoms in many histamine-related conditions. This makes sense now that we know it helps to address factors that trigger histamine, such as microbes, inflammation, and toxins.

Here’s a list of some of the ways it can help:

  1. Improves allergic rhinitis (runny/congested nose) in rats (24)
  2. Decreases activity of eosinophils, one of the main histamine-releasing cells (25)
  3. Increases death of inflamed (highly active) eosinophils (26)
  4. 50% decrease in migraines/headaches (27)
  5. Applied topically, improves eczema (atopic dermatitis) (28)
  6. Improves chronic bronchitis (29)

Some people are concerned that NAC can actually increase histamine. After all of the research I’ve done, the only studies I could find that support this theory used extremely high doses (10,000mg), often in an IV. We shouldn’t assume this applies to oral NAC supplementation for 2 reasons. First, some people have an allergic (histamine) reaction to even normal saline water IVs, likely because of allergy to the antiseptics used to clean the materials. (30) Second, any nutrient in high amounts tends to create more reactions and put the user at risk of negative effects. This applies to basic nutrients such as Vitamin C, magnesium, and even water. Using the right dose matters!

Already, it seems this antioxidant can do anything, and is extremely useful for our health, and we’re only halfway through its benefits! Let’s keep going so you can see what you’ve been missing out on if you’re not using it.

6. Has Anti-Cancer Properties

NAC may offer anti-cancer benefits since it works to protect cells from harmful substances that could mutate DNA. A review of the literature found that NAC may be helpful in preventing abnormal cells from becoming cancerous, while also alleviating symptoms of chemotherapy. (31) Multiple other studies indicate NAC’s anti-cancer benefits include improving DNA repair and supporting normal cellular function, among others. (32) In fact, a study of breast cancer tumors found that NAC greatly reduced the expression of a marker of cell survival, as well as expansion into new tissues. (33)

To sum up:

“A number of studies performed since 1984 have indicated that NAC has the potential to prevent cancer and other mutation-related diseases. N-Acetylcysteine has an impressive array of mechanisms and protective effects towards DNA damage and carcinogenesis…” (32)

However, it’s important to note that the same substance that makes us healthy can also make cancer cells healthier and therefore able to spread. While many antioxidants, including NAC, may decrease risk of cancer, they’re also thought to be counterproductive once cancer is already established. Please be sure to discuss with your healthcare team before adding it.

7. NAC Supports Mental Health

NAC supports healthy brain function and can aid in the treatment of various mental disorders. A double blind, placebo-controlled trial showed a significant decrease in OCD symptoms following supplementation with 2,400mg of NAC for 12 weeks. (34) What’s even more remarkable is that all participants were treatment-resistant, having failed traditional therapy with antidepressants, and benefits were seen as early as 4 weeks in.

In addition, NAC can help with addiction by reducing cravings and influencing brain receptors, as well as improve symptoms of schizophrenia and bipolar disorder. (31) For example, one study found that there were significant improvements in working memory following 6 months of NAC supplementation for bipolar and schizophrenic patients. (35)

8. Supports the Thyroid

Increased burden of pro-oxidants can lead to low thyroid hormone, which creates a double-edged sword that can wreak havoc on our bodies. Particularly, Hashimoto’s thyroiditis, a common autoimmune disease, can be triggered by a harmful imbalance of increased oxidants and decreased antioxidants. (36) The antioxidant power of NAC can neutralize pro-oxidants, leading to a healthy balance again. Consequently, it can improve the health of thyroid cells and ultimately, in one animal study of Hashimoto’s, restore the thyroid to its normal state. (37) Besides being an antioxidant, NAC can address other triggers of autoimmunity and thyroid imbalance by reducing inflammation, high toxic loads, and immune-triggering microbes.

9. NAC Is Useful for Acne

Since NAC supports the immune system and has anti-inflammatory properties, many use it as an effective acne treatment. One study found that pimples were significantly reduced with usage of a 5% NAC topical ointment compared to the placebo group. (38) The researchers discovered its benefits include the ability to reduce sebaceous gland activity.

10. NAC’s Role in Biofilm Reduction

We’ve discussed how NAC can act as a decongestant, breaking up excess mucus. It also has the power to break up biofilms, which are a gummy layer that protects harmful microbes from detection by your immune system. NAC therefore makes it easier for your immune system (and medications) to detect and clear microbes. (8) To test NAC’s effectiveness against biofilm production, one study recruited 40 participants that had previously undergone unsuccessful treatment for H pylori. H pylori is a common bacteria that infects the stomach, causing symptoms of GERD and other gut issues. Following NAC supplementation, 65% of the participants cleared H pylori, compared to 20% who received the placebo. (39)

SUMMARY: Even though I’ve been using NAC for years in my functional wellness practice, I’m still in awe of its benefits. It boosts liver health, detoxification, and the immune system. It improves hormonal issues, and supports the brain, mood, thyroid, and skin. It has antioxidant, anti-inflammatory, anti-cancer, and decongestant properties. DOSING: Speak with your practitioner. In general, effectiveness starts at 600mg and goes up to 2,400mg/day. May be best on an empty stomach, but can be taken with meals. We don’t recommend using it forever, since it’s not an essential nutrient and is high in sulfur which can cause issues when overdone. Balance is key! Get here.

If you’re experiencing any of the issues in this post and you’d like someone to partner with you to feel your best, we’re here for you! To learn more about what we do to get to the root causes of your symptoms, click here. Or, start our online program and be guided step by step to revitalize your health and energy.


  1. Cysteine supplementation improves the erythrocyte glutathione synthesis rate in children with severe edematous malnutrition. 2002.
  2. Glutathione synthesis is diminished in patients with uncontrolled diabetes and restored by dietary supplementation with cysteine and glycine. 2010.
  3. Role of N-acetylcysteine treatment in non-acetaminophen-induced acute liver failure: A prospective study. 2017.
  4. N-acetylcysteine protects against motor, optomotor and morphological deficits induced by 6-OHDA in zebrafish larvae. 2018.
  5. Depletion of Glutathione during Oxidative Stress and Efficacy of N-Acetyl Cysteine: An Old Drug with New Approaches. 2015.
  6. Interventions for paracetamol (acetaminophen) overdose. 2006.
  7. Effect of N-acetylcysteine on mucosal immunity of respiratory tract. 2018.
  8. The effect of N-acetylcysteine on biofilms: Implications for the treatment of respiratory tract infections. 2016.
  9. Effect of Orally Administered N-Acetylcysteine on Chronic Bronchitis: A Meta-analysis. 2019.
  10. A Review on Various Uses of N-Acetyl Cysteine. 2017.
  11. A trial of antioxidants N-acetylcysteine and procysteine in ARDS. The Antioxidant in ARDS Study Group. 1997.
  12. Attenuation of influenza-like symptomatology and improvement of cell-mediated immunity with long-term N-acetylcysteine treatment. 1997.
  13. Inhibitory effect of N-acetylcysteine on adherence of Streptococcus pneumoniae and Haemophilus influenzae to human oropharyngeal epithelial cells in vitro. 2000.
  14. The Effects of S-Carboxymethylcysteine and N-Acetylcysteine on the Adherence of Moraxella catarrhalis to Human Pharyngeal Epithelial Cells. 1999.
  15. N-acetylcysteine for prevention and treatment of COVID-19: Current state of evidence and future directions. 2022.
  16. N-acetylcysteine for polycystic ovary syndrome: a systematic review and meta-analysis of randomized controlled clinical trials. 2015.
  17. N-acetyl cystein improves pregnancy rate in long standing unexplained infertility: A novel mechanism of ovulation induction. 2004.
  18. N-acetyl-cysteine as adjuvant therapy in female infertility: a systematic review and meta-analysis. 2020.
  19. Dietary supplements for treatment of endometriosis: A review. 2022.
  20. A promise in the treatment of endometriosis: an observational cohort study on ovarian endometrioma reduction by N-acetylcysteine. 2013.
  21. Effects of various compounds on histidine decarboxylase activity: active site mapping. 1985.
  22. Generation of nitric oxide from nitrovasodilators modulates the release of histamine from mast cells. 1994.
  23. Ambroxol inhibits the release of histamine, leukotrienes and cytokines from human leukocytes and mast cells. 1999.
  24. N-acetylcysteine exerts therapeutic action in a rat model of allergic rhinitis. 2013.
  25. Inhibitory effects of N-acetylcysteine on the functional responses of human eosinophils in vitro. 2007.
  26. Modulatory effects of N-acetyl-L-cysteine on human eosinophil apoptosis. 2007.
  27. Reduction in Migraine and Headache Frequency and Intensity With Combined Antioxidant Prophylaxis (N-acetylcysteine, Vitamin E, and Vitamin C): A Randomized Sham-Controlled Pilot Study. 2020.
  28. Effects of Topical N-Acetylcysteine on Skin Hydration/Transepidermal Water Loss in Healthy Volunteers and Atopic Dermatitis Patients. 2015.
  29. The effect of oral N-acetylcysteine in chronic bronchitis: a quantitative systematic review. 2000.
  30. Acute allergic reaction after intravenous saline injection: an unusual presentation of chlorhexidine allergy. 2014.
  31. Medical and Dietary Uses of N-Acetylcysteine. 2019.
  32. Mechanisms of N-acetylcysteine in the prevention of DNA damage and cancer, with special reference to smoking-related end-points. 2001.
  33. Pilot study demonstrating metabolic and anti-proliferative effects of in vivo anti-oxidant supplementation with N-Acetylcysteine in Breast Cancer. 2017.
  34. N-acetylcysteine add-on treatment in refractory obsessive-compulsive disorder: a randomized, double-blind, placebo-controlled trial. 2012.
  35. Cognitive effects of adjunctive N-acetyl cysteine in psychosis. 2016.
  36. Oxidative Stress and Advanced Glycation End Products in Hashimoto’s Thyroiditis. 2016.
  37. N-Acetylcysteine and 15 Deoxy-Δ12,14-Prostaglandin J2 Exert a Protective Effect Against Autoimmune Thyroid Destruction in Vivo but Not Against Interleukin-1α/Interferon γ-Induced Inhibitory Effects in Thyrocytes in Vitro. 2010.
  38. The Potential Uses of N-acetylcysteine in Dermatology: A Review. 2019.
  39. N-acetylcysteine as powerful molecule to destroy bacterial biofilms. A systematic review. 2014.

Leave a Reply

Your email address will not be published. Required fields are marked *

    Downloading the guide will also subscribe you to our email newsletter.