N-Acetyl Cysteine, or Acetylcysteine, or simply NAC is the supplement form of the semi-essential amino acid L-cysteine. It is semi-essential because the body can make it on its own, although it also depends on external supply of this important nutrient through the food we eat.
The natural form of cysteine can be found in several protein-rich foods, e.g. beef, chicken, eggs, and others. However, NAC is not naturally found in food because it is a synthetically manufactured compound. When ingested, it is broken down into the amino acid cysteine, which has a few important functions in the human body.
NAC has been sold as a dietary supplement for decades. Its most common use as a supplement is to promote the production of the intracellular antioxidant glutathione. It also has a few other uses and it has been studied as a potential remedy for different health conditions.
For many years, numerous brands of NAC supplements have been available for sale on Amazon, but all of a sudden they decided to remove all NAC-containing products from their site and completely ban sellers from listing any supplements that contain this compound.
Amazon’s decision came shortly after the FDA started sending out warning letters to companies that were making unproven therapeutic claims about products that contain NAC. Although the FDA hasn’t completely banned the sale of this compound or reached a final decision on its status as a dietary supplement, Amazon saw it was safer for them to just pull it off their site pending a final decision from the FDA.
The good news is that there are still plenty of other reliable vendors where you can buy high-quality NAC supplements. The following are five of the best NAC brands you can buy online.
Thorne is one of the most reputable practitioner supplement brands in the USA. Such practitioner brands are usually sold at doctors’ offices and through authorized online retailers. Similar to other professional brands in its class, Thorne has outstanding sourcing, testing and quality control standards.
Their products are top-notch quality and you’ll hardly find any user complaints in this regard. What many customers complain about though is the premium price point of this brand, which is a typical drawback of practitioner brands in general. Many users who have tried and trust this brand don’t mind paying a little extra, but if your budget doesn’t allow, check out some of the cheaper recommendations below.
Thorne’s NAC comes in capsule form and a bottle of 90 capsules (500 mg each) costs $25.
2. Life Extension
Life Extension is a well-established company in the supplement industry with a massive selection of all sorts of dietary supplements. They use quality ingredients that are tested for purity and safety in their US-based manufacturing facility.
This company distinguishes itself from others by basing their formulas and claims on scientific research and they are deeply invested in consumer education. However, some of the health claims they make about certain products may be a little overblown and lack adequate scientific evidence. You should always do your own research regardless of how reliable the brand is.
Life Extension’s NAC comes in capsule form (600 mg each) and costs about $10 per bottle of 60 capsules.
3. Source Naturals
Source Naturals offers many decent supplements at very reasonable prices. They are mostly focused on distributing their products to local retail stores across the USA and they don’t seem to sell directly to consumers at the moment. You can also purchase their products from some online shops (see link below).
NAC by Source Naturals comes in tablet form with each containing 600 mg. One bottle of 120 tablets costs a bit over $16.
Note: NAC naturally has a bad smell and taste, so if you have a problem swallowing unpleasant tablets, you may want to go with a capsule form instead.
4. Designs for Health
Since this post is about top quality brands, here’s one of the tip-top premium practitioner brands on the market! Designs for Health isn’t very popular online because the company is more focused on marketing their supplements locally through the healthcare practitioner channel.
Their premium prices may drive off most price conscious consumers, but they do have many loyal customers who trust the quality of their products. If you don’t mind the high price, this is an excellent brand to try out.
One possible issue with this product is that each capsule contains a dosage of 900 mg, which may be too much for users who prefer to take a lower dosage at once.
Each bottle of Designs for Health NAC has 120 capsules (900 mg each) and costs $44 and some change.
Every supplement user must have heard about NOW by now (pun intended). This is one of the largest producers of nutritional supplements that offers many quality products at low prices.
NOW’s NAC comes in two forms: capsules (600 mg), and tablets (1000 mg). The capsule formula comes with two additional ingredients: selenium and molybdenum, which are both trace minerals that help the body utilize NAC and make the antioxidant glutathione. If you are mainly interested in the antioxidant boosting effect of NAC, this may be a more beneficial formula to take, especially if you don’t already consume adequate amounts of these two trace minerals from food.
Caution: Do not buy the capsule formula if you intend to take more than 600 mg of NAC per day. By taking more than one capsule, you could be consuming too much of the minerals selenium and molybdenum, which may cause unwanted side effects. Also, because of these two extra ingredients, some people may not tolerate this formula.
Note: Black specks may appear in the capsules due to oxidation of the mineral ingredients and that is normal. It is not mold as some have suspected and it doesn’t affect product quality (according to the manufacturer). The tablets don’t contain the additional minerals and don’t have this issue.
You can find and order these supplement brands as well as others at the PureFormulas online store. They offer great service and free shipping on most items.
Questions and answers
The following are a few frequently asked questions about NAC with quick answers.
What are the benefits of NAC?
NAC is a form of the amino acid L-cysteine, which has different roles in the human body. Its most important function is serving as a precursor for the intracellular antioxidant glutathione. Supplementation with NAC increases the levels of glutathione in the body and can help combat cellular oxidative stress and damage.
Another common use of NAC is detoxification of the liver as it can help get rid of some toxic metals. It is medically used to prevent liver and kidney damage caused by acetaminophen poisoning.
NAC also works as a mucolytic (mucus thinner) and it has been used to reduce mucus buildup in the respiratory system and improve breathing in certain cases. Additionally, it may help reduce inflammation in the lungs.
Because of its ability to cross the blood-brain barrier and boost glutathione production in the brain, NAC has also been used to combat several mental health problems that are associated with oxidative stress. However, there is very little scientific evidence and contradicting personal experiences regarding NAC’s benefits for brain health and cognitive functions.
There is no evidence that NAC increases energy, except for varying personal experiences.
Why does NAC have an awful smell?
NAC contains sulfur, which is the source of the bad (rotten egg) smell. The foul smell is normal for this compound and it does not indicate bad quality. Capsules help mask the bad smell and taste as opposed to tablets and powder forms.
Does NAC have side effects?
While generally considered safe with no significant side effects, each person may respond differently to this compound and some people can’t tolerate it.
Possible side effects include nausea, abdominal discomfort, vomiting, diarrhea, skin rash, and fatigue. Some people may experience insomnia when taking NAC in the evening.
It is normally not recommended to take more than 1,200 mg of NAC per day, unless directed by your doctor. The higher the ingested dosage, the more likely you’ll experience adverse effects.
Why can’t you buy NAC on Amazon anymore?
Up until early 2021, there used to be many NAC brands offered for sale on Amazon. But then they noticed that the FDA has been sending warning letters to companies that were marketing NAC-containing products as a medication for some health conditions, which is against the FDA’s guidelines.
There is a big debate and a legal battle between the FDA and supplement manufacturers and advocates over the classification of NAC. It has been used as both a dietary supplement and a medication, although it is more commonly considered a supplement. The FDA hasn’t reached a final decision on this matter yet and some manufacturers are hopeful that they will be allowed to continue selling it as a dietary supplement, which has been the case for decades now.
In the meantime, Amazon decided to play it safe and remove all products that contain NAC from their site, at least until the FDA makes its final decision on how to classify this ingredient.
Is NAC worth taking?
There are some potential benefits of NAC, but not everyone may find it useful. A lot of the rave reviews and claims you read on different sites may be exaggerated and very subjective. Healthy people should have no reason to take this supplement since the body can make the amino acid cysteine on its own and also get it from various foods.
Each person’s body may respond differently to NAC and some people who took it only experienced negative side effects with no positive changes. It is better and safer to consult with your doctor before taking any supplement for any health issue you have.