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Last modified on January 9th, 2023
N-acetyl cysteine or NAC is a popular supplement. Recently, people started wondering if the NAC supplement is banned and, if so, why.
Below we cover the key things you need to know about the topic and answer why the NAC supplement is banned at least at some retailers.
What is NAC?
N-acetyl cysteine is an amino acid considered semi-essential. Semi-essential means your body can produce it from other amino acids, methionine, and serine. An essential amino acid is one you have to get through your diet or dietary supplement products.
The amino acid L-cysteine is found in high-protein foods, including chicken and turkey and seeds and legumes.
NAC is a supplement form of cysteine. There are many key reasons we need to consume enough cysteine and NAC. One of the biggest is that it helps replenish the antioxidant glutathione, our most powerful.
Health Benefits of NAC
Below, we detail some of the many health benefits of NAC, at least based on what we currently know. These extend to taking it in supplement form in particular.
- NAC is essential to make glutathione. Glutathione is your body’s most important antioxidant. Glutathione is needed for immune health and to combat cellular damage. The antioxidant properties of glutathione may allow it to help with many conditions associated with oxidative stress, including infertility, heart disease, and mental health conditions.
- The use of NAC can help promote your body’s natural detox pathways. It can prevent the side effects of toxins from the environment and drugs. For example, doctors will often use intravenous N-acetylcysteine in emergency departments in people with acetaminophen overdose to prevent damage to the kidneys and liver and help with renal function.
- Since NAC has powerful antioxidant benefits, it’s thought to be beneficial for the liver’s health, and it may help combat symptoms of various liver diseases and disorders.
- NAC regulates levels of glutamate. Glutamate is a neurotransmitter in your brain required for normal activity. Having too much glutamine and not enough glutathione increases the risk of a substance use disorder, bipolar disorder, and OCD.
- Some evidence shows NAC can help decrease depression and bipolar disorder symptoms and improve functionality.
- NAC supplements may help with withdrawal from substances, including cannabis use disorder, nicotine, and cocaine.
- One of the big reasons many people opt to supplement with NAC is because it can help with respiratory health and conditions. Since it’s an antioxidant, NAC can replenish your glutathione levels and reduce inflammation in the lung tissues and bronchial tubes.
- People with chronic obstructive pulmonary disease (COPD) have oxidative damage and inflamed lung tissue, which causes their airways to restrict. NAC supplements can improve symptoms of COPD and reduce lung decline. Sometimes NAC is used as adjuvant therapy in conventional medical settings for lung and respiratory disorders.
- Someone with chronic bronchitis might benefit from NAC, and it may decrease the severity of wheezing, coughing, and respiratory attacks related to the condition.
- Other lung and respiratory conditions that NAC has the potential to help include sinus and nasal conditions due to allergies and infections, cystic fibrosis, and pulmonary fibrosis.
- When NAC helps your body replenish glutathione, it boosts brain health, which can help with behavior, memory, and learning. Glutathione also reduces oxidative damage to brain cells associated with aging. Conditions affecting brain and memory may benefit from taking NAC. For example, some people find it helps with Parkinson’s disease and symptoms of Alzheimer’s. NAC supplements can improve dopamine function and symptoms like tremors.
- There is evidence of NAC improving male fertility, and it may also help females with infertility who have polycystic ovary syndrome (PCOS). There’s some evidence to suggest NAC can induce or help the ovulation cycle.
- Obesity and high blood sugar lead to inflammation of fat tissue, damaging insulin receptors and increasing the risk of type 2 diabetes. In animal studies, NAC has been found to stabilize blood sugar by decreasing inflammation in fat cells. This then improves insulin resistance.
- Heart disease risk could be reduced with NAC. Oxidative damage is often the cause of heart disease and can lead to heart attacks and strokes. NAC can potentially reduce heart disease risk by reducing oxidative damage to heart tissues.
- NAC can also increase nitric oxide production so your veins can better dilate, which improves blood flow. That means blood moves back to your heart faster, lowering your risk of heart attacks.
- There are potential benefits for immune health and immune cells, likely due to NAC’s effects on glutathione production. For example, NAC could restore immune function in some people. It’s been largely studied in HIV, but there have been possible benefits for other situations involving compromised immunity in test-tube studies.
- Some test-tube studies link the use of NAC to the death of cancer cells and a blocked ability of cancer cells to reproduce.
Most research shows NAC is likely safe as a supplement or used as a prescription. Mild side effects can include diarrhea, nausea, vomiting, and constipation. NAC can slow blood clotting, so people with bleeding disorders or those individuals on blood-thinning medications shouldn’t take it.
Was the NAC Supplement Banned?
You might wonder if the NAC supplement was banned despite all the listed benefits above.
The short answer is that it’s complicated, and there’s a lot of pushback within the dietary supplement industry and among other people who promote natural products.
It’s possible that this year, people in the U.S. could lose access to dietary supplements containing NAC unless the industry can convince the U.S. Food and Drug Administration the glutathione precursor was used as a supplement or food ingredient before the mid-1990s.
So what happened?
The FDA says that since NAC was approved in the 1960s as an inhaled drug for obstructive lung disease and again in the mid-1980s to treat acetaminophen toxicity, it’s excluded from being a dietary supplement.
The FDA is saying there’s the potential these products don’t meet their dietary supplement definition.
This is even though oral N-acetylcysteine products have and NAC-containing supplements been sold for more than three decades by supplement companies.
Why Did Amazon Pull NAC-Containing Products
The issue of the FDA and NAC caught worldwide attention in 2021 when Amazon and other key retailers decided to pull the products. A series of warning letters were issued by the FDA indicating that the agency wanted to limit the availability of NAC as a dietary supplement.
Naturopathic practitioners and functional medicine providers often recommend the supplement, so the warning letters coming from the FDA created a lot of controversy, frustration, and anger.
The initial warning letters from the FDA started going out in the summer of 2020 when companies marketing NAC as hangover cures were targeted. The warning letters had language showing the FDA’s wider intentions, however.
Based on the letters it sent, the agency reverted to the position that NAC is a pharmaceutical ingredient, even though it has permitted its use as a supplement for decades.
Amazon announced in May 2021 that it was going to eliminate all products with NAC from its digital shelves.
The FDA invoked the Drug Exclusion Provision to challenge sales of supplements with NAC.
While we can’t know for sure, Amazon may have been quick to pull NAC from its shopping options because it had, according to some, played a role in promoting fraudulent COVID treatments or ones that were questionable. Amazon seemed very eager to avoid large-scale enforcement and make regulators happy.
The online retailer issued a statement when it pulled NAC, saying that third-party sellers must follow all laws and regulations and Amazon policies.
In November 2021, right before Thanksgiving, the FDA issued a request for information about the past use of NAC in supplements and relevant safety data. If the industry can prove that NAC was used in supplements before 1994, it would qualify as an old dietary ingredient, which would exempt it from prior drug exclusion.
The American Herbal Products Association, the Natural Products Association, and other industry organizations focusing on holistic health and wellness and nutraceuticals have been coming together to fight the FDA’s proposed actions.
There are numerous ongoing petitions and lawsuits.
Does the FDA ban NAC?
So is NAC banned by the FDA?
In short, no. Currently, the NAC supplement is banned by Amazon and some other retailers, but the FDA does not ban it.
The supplement could be in the future, though, depending on how things go this year.
Why Is NAC Banned?
As we mentioned above, NAC isn’t technically banned, at least not by the FDA, although Amazon doesn’t sell it.
The honest answer is that we don’t know why it was suddenly targeted.
We haven’t been able to find any reports of major side effects, and the FDA doesn’t seem to allude to that being the reason. The FDA seems to be targeting NAC based on its technicality being used as a pharmaceutical versus a supplement.
It could be that the FDA is considering exploring more potential for NAC as a pharmaceutical, which can have something to do with their warning letters, but that’s purely speculation on our part right now.
The FDA has said that it’s considering the position of some of the organizations who are petitioning to have it remain a dietary supplement, but we don’t know yet how that will turn out.
Several retailers still have NAC products, and it is legal for them to. It was a personal decision by Amazon to pull it and make it not available to shoppers, and they weren’t required to.
We linked a couple of our favorite NAC products that are still available and that you can buy online.
Where to Buy NAC Currently
We don’t know if in the future this will change or if NAC banned by FDA regulators and public health officials will become a reality, but for now, it is still available and can legally be sold by retailers. You can still find these products for use by oral administration.
The following are some available options and links to where you can buy each.
Doctor’s Best NAC Detox Regulators
NOW NAC Caps
Pure Encapsulations NAC
Solgar NAC 600 mg
Final Thoughts About Whether the NAC Supplement is Banned
While the NAC supplement is not currently banned by the FDA, at some point, it could be in the future. For now, companies have just received warning letters that the FDA is reviewing how it’s used and marketed, but Amazon proactively pulled its products last year in response to the letters.