9 Best NAC Supplements 2024

N-acetyl cysteine (NAC) is a supplement that is used for many health purposes. It is a derivative of the amino acid cysteine and is commonly used as a precursor for the antioxidant glutathione.

NAC is not found in large amounts in food. It can be obtained from dietary sources of cysteine, which is an amino acid that is used by the body to synthesize NAC. However, it is important to note that NAC cannot be obtained in significant amount from diet alone since the body's capacity to transform cysteine into NAC may be limited by factors like age, lifestyle, and general health. For those who wish to raise their NAC levels, supplements might be a better choice.

Potential Benefits of NAC

A. Potent Antioxidant
NAC is required for the production and replenishment of glutathione, together with the two other amino acids, glutamine and glycine.

Glutathione is one of your body’s most vital antioxidants. Glutathione aids in scavenging free radicals that might harm your body's cells and tissues. It is crucial for cellular damage prevention and immune system support.

B. Liver Health
NAC has been shown to help protect the liver from damage caused by certain toxins, such as acetaminophen. NAC administered intravenously at a total dose of 300 mg/kg can be safely used to prevent liver necrosis in cases of paracetamol (acetaminophen) poisoning (Source, Source)

C. Respiratory Health
NAC has been found to help with conditions such as bronchitis, COPD, and pneumonia. Studies showed that patients treated with NAC had significantly and consistently fewer exacerbations of chronic bronchitis or COPD, although this protective effect was more apparent in patients without evidence of airway obstruction. 

Another study also suggests that NAC inhibited oxidative stress and reduced the inflammatory factors in pneumonia. Treatment with antioxidants NAC might reduce oxidative and inflammatory damage in pneumonia patients.

D. Cardiovascular Health
NAC has been demonstrated to help lower oxidative stress in the body and improve cholesterol levels, which may help prevent cardiovascular disease.

E. Mental Health
NAC has been shown to have a positive effect on certain mental health conditions, such as depression and obsessive-compulsive disorder. According to some studies, treatment with N-acetylcysteine improved depressive symptoms. Firthermore, another studiy also suggest that NAC might be effective as an augmentative agent in the treatment of moderate-to-severe OCD.

Best NAC Supplements

1. Nutricost N-Acetyl L-Cysteine (NAC)

Nutricost N-Acetyl L-Cysteine (NAC)

Nutricost's N-Acetyl Cysteine contains 600 mg of high quality NAC in each serving (1 serving is just 1 capsule). N-Acetyl L-Cysteine, often known simply as NAC, is a stable form of the non-essential amino acid L-Cysteine. Each bottle of this Nutricost NAC product contains 180 capsules of NAC for 180 servings. 

This product is non-GMO, gluten free, soy free, vegetarian friendly, and made in a GMP compliant, FDA registered facility. Each batch of every Nutricost product is tested by ISO-accredited laboratories to insure safety and quality.

4.6 out of 5 - more than 5,800 global ratings

I have been struggling with my asthma and allergies for the last 10 days, even had to use my oxygen tank. This is the 3rd day of taking this product and the issues are gone and now off oxygen tank. Would recommend this to anyone with asthma or allergy issues.

2. NOW Supplements, NAC (N-Acetyl Cysteine) 600 mg with Selenium & Molybdenum

- Free Radical Protection
Take 1 NAC veggie capsule with selenium and molybdenum twice daily for free radical protection and to maintain cellular health.

- Important Note for This Product
Black spots may appear in NAC because of a normal oxidative reaction, but product is safe to consume. These spots are not mold or any other micro-contamination. Micro-testing has been performed to assess product safety.

- Certifications/Classifications
Non-GMO, vegan/vegetarian, made without gluten, kosher, dairy free, egg free, nut free, soy free, UL certified

- GMP Quality Assured
NPA A-rated GMP certification means that every aspect of the NOW manufacturing process has been examined, including our laboratory/testing methods (for stability, potency, and product formulation).

4.6 out of 5 - more than 10,000 global ratings

This was recommended for my daughter to take to help her focus better in school and so I tried it too. I woke up one morning after taking this for 3 days and my brain fog was gone!! I was awake and not tired. I slept better and refreshed! I’m so impressed! Now the whole family is taking it everyday.

3. Doctor's Best NAC Detox Regulators with Seleno Excell

Doctor's Best NAC Detox regulators boosts glutathione production in the brain, liver and other organs, supports enzymes that neutralize natural and manmade toxins, and promotes the healthy functioning of numerous important proteins. Moreover, NAC is proven to boost glutathione production. Selenium and Molybdenum are essential for facilitating glutathione's role in supporting energy

The three nutrients in this product-nac (N-acetyl Cysteine) and the essential minerals selenium, and Molybdenum -sustain glutathione. Non-GMO/ Gluten Free/ Soy Free/ Vegetarian

4.6 out of 5 - more than 1,400 global ratings

First, this makes it a lot easier to stay regular and um, push. I already take ginger, probiotic, ACV, and a fiber colon cleanse to help with that, but I still get constipated at times, and never have any easy time getting anything out because inflammation. This has gotten me regular and made it easy... stools are proper color now too. Off of this, they are light wheat/tea colored. Yeah, that's a symptom of liver problems. I've stopped getting pain/cramps in my sides where my kidneys are located. My skin parlor has returned to normal. I can't even TELL I had any problems before.

4. Pure Encapsulations NAC 600 mg

- Antioxidant Support
NAC provides powerful nutritional support to cells as an antioxidant, specifically supporting healthy lung functioning through its mucolytic capability.*

- Lung Support
NAC provides powerful nutritional support to cells as an antioxidant, specifically supporting healthy lung functioning through its mucolytic and antioxidant action.*

- Pure Quality
Our supplements are made with only premium ingredients sourced from trusted suppliers and guided by our nutritional experts, then carefully manufactured and tested to verify their potency and purity.

- Pure Difference
What makes us different isn't just our process or what goes into our supplements -- what we leave out matters, too. Pure Encapsulations products are free from wheat, eggs, tree nuts & peanuts, gluten, artificial colors, flavors & sweeteners, coatings and shellacs, GMOs, and unnecessary binders, fillers & preservatives.

4.7 out of 5 - more than 1,550 global ratings

Great quality product, lungs health improvement
Having chronic COPD and asthma, my dad said he felt the results the first week he started taking this product.

5. BulkSupplements.com NAC Powder (N-Acetyl L-Cysteine)

- Source of Antioxidants 
N-Acetyl L-Cysteine, or NAC supplement, is a great source of antioxidants, which protects cells from free radical damage.* This makes it an important part of overall health and well-being.* In addition to its antioxidant content, our NAC powder, or NAC supplement, is pure without any fillers.

- Supports Lung Health 
N-Acetyl L-Cysteine powder, or NAC supplement, is an amino acid supplement that may support lung health or respiratory health. This powerful antioxidants supplement may helps support lung function and it's health, making it a great way to support overall health and wellness.*

- Promotes Healthy Mood 
N-Acetyl L-Cysteine, in NAC 600mg powder, may be a supplement for mood health.* In addition, NAC suppelments may help supports healthy balance of neurotransmitters, and promoting a sense of calm and well-being.* Add NAC powder into your diet or any healthy regimen for a healthy and balanced mood.*

- Pure and Clean Supplement 
Our N-Acetyl L-Cysteine, in NAC powder form, is pure and natural without any fillers, additives, and artificial flavors. Not only that this supplement is filler free, this NAC supplement has 600mg of NAC per serving. And, it's dairy free, gluten free and especially no added sugars! Add NAC powder to any beverage of your choosing!

4.5 out of 5 - more than 1,250 global ratings

I was so stressed out ,depressed ,had no motivation..ever since I started taking nac it makes me feel good I mean I'm running hitting gym all the time my skin and hair starting to get better you dont obsess over things it's just an amazing supplement to try.

6. Thorne NAC - N-Acetylcysteine - 500mg

- Immune Support
Enhances immune function by supporting the production and function of immune cells*

- Clears Mucus
Helps break up mucus, making it easier to clear from congested lungs and sinuses*

- Antioxidant Support
Enhances antioxidant activity to promote a normal inflammatory response in the lungs*

- Liver & Kidneys
Supports liver and kidney detoxification*

4.7 out of 5 - more than 800 global ratings

I love this stuff! Opens up my lungs and for some reason loosens up the front of my neck too. In fact I think it also has a positive effect on my thyroid.

7. NAC Supplement (N-Acetyl Cysteine) 1000mg with Glutathione 50mg

- Special Features 
1000mg servings of purified N-Acetyl Cysteine NAC, fortified with reduced glutathione antioxidant to promote high active properties and better overall bioavailability. Made with real NAC that may produce a natural potent smell.

- Benefits & Use 
A pure NAC supplement that offers dual-action glutathione development by combining both NAC and glutathione in the same supplement. Enjoy double-strength antioxidant benefits that promote liver support, lung health, and brain health.

- Dosage & Servings 
Every bottle contains 180 total capsules that offer 90 potent servings of NAC with glutathione. It only takes 2 capsules per serving to receive 1000mg of NAC with 50mg of glutathione in its most active reduced state.

- Quality Ensured 
3rd party lab tested, Non-GMO N Acetyl L Cysteine. Made in the USA and does not contain gluten, dairy, eggs, peanuts, soy, wheat, & yeast.

4.6 out of 5 - more than 400 global ratings

I particularly like this company's NAC because it comes in a capsule and is easy to swallow. It's also a great value. The other factor is it unlike some NAC products it doesn't have a strong smell.

8. Z-Dtox Supplement

z-dtox zelenko

Dr. Vladimir Zelenko’s groundbreaking work on the immune system has led to this exciting breakthrough.

Your immune system can be weakened by over 300 different primary immunodeficiency disorders, poor diet, lack of sleep, and adverse reactions to various vaccines.

That’s where Z-DTOX comes in! Z-Dtox is Dr. Zelenko’s proprietary combination of ECGC, NAC, Zinc, Vitamin C, and Vitamin D.

  • Epigallocatechin gallate (EGCG) is an extract of green tea and is a powerful zinc Ionophore (zinc delivery system).
  • N-acetyl cysteine (NAC) is a supplement form of cysteine. It may prevent blood clots and is an antioxidant.
  • Zinc is critical for immune cell development. Dozens of different enzymes in the body rely on zinc.
  • Vitamin C is an essential nutrient involved in the repair of tissue and the enzymatic production of certain neurotransmitters.
  • Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects.
Z-Dtox is more powerful than Z-Stack. It has EGCG instead of Quercetin, NAC, and higher dose Zinc. It is more appropriate for higher risk patients. For example, those people that have a dysfunctional immune system, risk of blood clots, older people and those with chronic medical conditions.

Z-Dtox also has 60 servings per container instead of 30 servings per container for Z-Stack.

Where to buy Z-Dtox: Z-Dtox is available on Dr Zelenko's website. Here is the link: Z Dtox Supplement 

To get 5% OFF, please use this coupon code: drfrancis

9. Pure Encapsulations NAC + Glycine Powder

Each serving size (1 scoop) contains: N-Acetyl-L-Cysteine (free-form) 1800 mg, Glycine (free-form) 1800 mg.

Glutathione is one of the main endogenous antioxidants. Found in virtually every cell of the body's glutathione defends against free radicals, in part by recycling other antioxidants. It also supports detoxification and other critical aspects of cell function.(1) Increased glutathione levels have been linked to supporting a reduction in oxidative stress and DNA damage.(2) Cysteine and glycine are necessary precursors for glutathione (GSH) synthesis, but the required amounts may not be met by dietary intake alone, particularly as we age.(3) 

Co-supplementation of these nutrients has been shown to promote intracellular glutathione levels.(4,5) In a small study involving older individuals, two weeks of supplementation with a combination of N-acety-l-cysteine (NAC) and glycine raised red blood cell (RBC) glutathione levels more effectively than either amino acid alone.(5) In one study, supplementation with the combination of NAC and glycine resulted in 32% higher RBC glycine, 46% higher RBC cysteine and a 53% increase in RBC GSH concentration. There was also a significant improvement in the ratio of reduced (active) GSH to oxidized glutathione (GSSG). Increased GSH was associated with improvement in antioxidant status as measured by F2-isoprostanes, as well as mitochondrial fatty acid oxidation.(6) 

In another study comparing young and older subjects, elderly subjects had 55% lower RBC glycine, 24% lower RBC cysteine, and 46% lower RBC glutathione at baseline, as well as lower reduced (active) GSH to GSSG ratios. Supplementation with NAC and glycine in elderly subjects resulted in RBC levels of glycine, cysteine, and glutathione, as well as GSH:GSSG ratio, comparable to young unsupplemented subjects.(4) NAC and glycine have been shown to maintain healthy cytokine release during times of metabolic stress.(7) Research suggests that glycine may moderate TNF╬▒ and promote IL-10 to support cytokine balance, and that glycine intake is positively associated with cardio-metabolic health.(8) 

Studies indicate that supplementation with NAC also supports mood and social functioning.(9) It is believed that cysteine influences the reward-reinforcement pathway by modulating the glutamate system.(10) NAC additionally promotes immune defenses and supports the health of epithelial cells and cilia in the respiratory tract.(11) The affinity of NAC for lung tissue, together with its natural sulfur content, allows it to disrupt disulfide bonds within mucus, thinning and easing its expulsion.(12) In a randomized, double-blind trial involving mostly older individuals, 600 mg of NAC twice daily showed significant support for respiratory and immune function.(13)

  1. Richie JP Jr, et al. Eur J Nutr. 2015 Mar;54(2):251-63.
  2. Zhang Q, et al. Medicine (Baltimore). 2018 Nov;97(45).
  3. Sekhar RV, et al.Am J Clin Nutr 2011 Sep;94(3):847-53
  4. Roes EM, et al. Clin Chem Lab Med. 2002 May;40(5):496-8.
  5. Guthikonda, et al. American Geriatrics Society Annual Scientific Meeting, 2006.
  6. Nguyen D, et al. J Clin Endocrinol Metab. 2014 Jan;99(1):169-77.
  7. Cruz M, et al. . J Endocrinol Invest 2008 Aug;31(8):694-9.
  8. Ding, et al. Circ Cardiovasc Genet. 2016 Dec;9(6):541-547.
  9. Berk M, et al. Biol Psychiatry. 2008 Sep 15;64(6):468-75.
  10. Grant JE, et al. Arch Gen Psychiatry. 2009 Jul;66(7):756-63
  11. Ozdemir ZC, et al.Hemoglobin. 2014;38(5):359-64.
  12. Tse HN, et al. Chest. 2013 Jul;144(1):106-18.
  13. De Flora S, et al. Eur Respir J J. 1997 Jul;10(7):1535-41.


a. Who Should Not Take NAC Supplement?

Your doctor might advise against using NAC if you have bleeding issues or asthma. Most likely, you will be instructed to stop NAC two weeks prior to any elective surgery.

If you're pregnant or breastfeeding, best consult your doctor before using NAC supplements.

Interactions. They may interact with blood thinners, nitroglycerin, and several blood pressure medications. Therefore, best to consult your doctor before taking this supplement.

b. What Are the Side Effects of Taking NAC?

Common side effects of NAC include:
  • Nausea
  • Diarrhea
  • Upset stomach
  • Skin rash
  • Dizziness
In rare cases, NAC can cause more serious side effects, including:
  • Low blood pressure
  • Breathing difficulties
  • Allergic reactions, including swelling of the face, lips, tongue, or throat
It is advised to follow to the instructions on the product label and not take more than the advised dosage. If you experience any side effects while taking NAC, stop using the supplement and talk to your doctor immediately.

c. NAC vs Glutathione

Related Article


Popular posts from this blog

Zinc Gluconate vs Zinc Picolinate: What's the Difference?

NAC vs NAD vs NR vs NMN vs Niacin: What Are the Differences?

Dave Pascoe Supplement List 2024

18 Best Supplements to Reduce Cytokine Storm: Advanced Guide

Best Anti Aging Supplements 2024: Unveiling the Science Behind Longevity Medicine (500+ Studies Analyzed)

10 Best NMN Supplements (2024 Review)

Dr. Zelenko's Z-Stack Vitamin Cocktail: Review 2024

Vitamin E 101 :Types, Benefits and Functions 2024

Terpenoids 101: What You Need to Know

Nebulized Hydroxychloroquine for COVID-19 Treatment - Vladimir Zelenko, M.D.