Is NAC Going Bye Bye?

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The Pure TheraPro Team

The Pure TheraPro Education Team is comprised of researchers from diverse backgrounds including nutrition, functional medicine, fitness, supplement formulation & food science. All articles have been reviewed for content, accuracy, and compliance by a holistic integrative nutritionist certified by an accredited institution.
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The buzz word in the supplement market today is “glutathione”—and for good reason! Nearly all chronic illness has this thing in common--LOW glutathione levels. Glutathione helps detoxify your system and is critical in supporting optimal immune function.

Glutathione supplementation comes in many forms, and NAC (N-acetyl cysteine)which is actually a PRECURSOR of glutathione is one form that has gotten lots of buzz lately, particularly regarding its use in managing respiratory illnesses such as COVID-19. As current researchers explore various options for managing disease and illness, pharmaceutical companies are vetting over NAC. The outcome? Some issues with semantics, ownership, FDA guidelines and sticky technicalities that may place NAC in supplement world jeopardy.

Recent Warning Letters

Is NAC going bye-bye? It definitely might get harder for consumers to order online or find on health food store shelves, due to recent warning letters to various supplement companies that sell products containing NAC.

The FDA sent out these letters due to a technicality that hasn’t been enforced, noting that NAC can’t be marketed as a dietary supplement. 1,170 products containing NAC were listed in the Dietary Supplement Label Database.

Although the director of the FDA’s Office of Dietary Supplement Programs said that these are simply warning letters at this time, there now is a rumor circulating in the supplement world that NAC may not be able to be sold as currently labeled for much longer, based on NAC being excluded from the definition of a supplement.

The FDA has not shown consistency over the years when it comes to supplement guidelines. In addition, it’s apparent that the FDA has shown a long-term bias in favor of pharmaceuticals. After all, the FDA has much more control regarding launching pharmaceuticals than supplements.  

The enforcement of NAC’s labeling as a drug and not a supplement is arriving at unique timing since NAC has hit the spotlight lately as one of many natural remedies that may help manage respiratory illnesses and viruses such as COVID-19.

Clinical trials studying NAC’s safety and efficacy in people with severe COVID-19 are already underway by pharmaceutical companies who are now claiming ownership of NAC as a drug, not a supplement, under these newly enforced guidelines. Dependent on the results of these trials, NAC may become shadow-banned from shelves and online stores and illegal to attain without a prescription.

Here is the official wording:

FDA has concluded that NAC products are excluded from the dietary supplement definition under section 201(ff)(3)(B)(i) of the Act [21 U.S.C. § 321(ff)(3)(B)(i)]. Under this provision, if an article (such as NAC) has been approved as a new drug under section 505 of the Act [21 U.S.C. § 355], then products containing that article are outside the definition of a dietary supplement, unless before such approval that article was marketed as a dietary supplement or as a food. 

What is NAC?

NAC, or N-acetyl cysteine, is a precursor to the formation of glutathione. Your body can intrinsically make it from amino acids, methionine and serine. Cysteine is found in certain foods, such as eggs, chicken, beans and seeds.

NAC is like the ingredients that make the bread—and the bread is glutathione. Glutathione is the body’s master anti-oxidant and is instrumental in fighting free radicals, reducing oxidative stress and properly detoxing the system from any invaders. Glutathione is instrumental for every system in the body.

Issues with NAC

NAC touts many claims regarding its benefits, from brain health to respiratory function, chronic fatigue and more. However, there might be an issue with NAC’s effectiveness in a large population of people.

Toxic overload, pharmaceuticals, infections, chronic illness and stress, aging and even EMF exposure can deplete natural stores of glutathione as well as your body’s ability to create more glutathione on its own.

Although NAC begins the process of glutathione creation, a body that can’t create will not be able to produce its end result.

Since NAC is glutathione’s precursor, it requires a series of steps and additional demands on the body in order to produce its end result. Back to the bread analogy—you may have the dough, but if your oven isn’t working properly, you won’t effectively make bread!

Others who may struggle with optimal benefit from NAC supplementation might be those with methylation issues and MTHFR. Methylation refers to the conversion of various chemical compounds in the body from the food we eat, supplements we take and even the sunshine we absorb in order to properly utilize these nutrients and remove wastes from the body.

Those with MTHFR and methylation issues, which might be as high as 60% of the population, possesses chronic inflammation, causing the body to struggle with these extra steps to get from point A to point Z. The body would do best with a direct route rather than taxing it with these additional jobs it’s simply too tired to perform correctly and efficiently.


Glutathione Benefits

A more direct route to increasing glutathione levels is supplementing with glutathione instead of NAC. Since the body can’t make what it can’t make, adding into the body what it’s lacking may seem like a logical solution. And the good news is that the FDA labels oral glutathione as a supplement. It’s not the spotlight at this moment to be re-labeled and owned by Big Pharma.

By reducing oxidative stress and inflammation, glutathione may help with multiple health issues that stem from chronic inflammation. This can impact cardiovascular disease, COPD, Alzheimer’s and other neurological diseases such as Parkinson’s. It may slow the progression of aging, help with skin issues, joint pain, energy levels and vitality and protect the body down to the cellular level. Research has demonstrated many of these health benefits. What’s interesting is that all disease states have a couple things in common—increased inflammation and low levels of glutathione.

Forms of Glutathione

Not all forms of glutathione, however, are the same. . .and not all forms of glutathione are under FDA review for losing their supplement labeling. Glutathione supplementation is still that--they are considered supplements. Here are some differentiators when comparing forms of glutathione. 

Reduced vs S-acetyl:

When comparing forms of glutathione, you have to understand bioavailability a bit better. Enzymes in your stomach break down glutathione before it can ever reach the bloodstream and become useful. This is the case in the reduced from. Most liposomal glutathione on the market uses the reduced form which isn’t the best-- it’s much cheaper which is why supplement companies use it. They add more mg per serving, which customers assume is better. The mg strength means nothing if the active ingredients can’t survive stomach acids and hence, are not fully absorbed.

This is why a main differentiator with forms of glutathione is the S-acetyl group attached to the sulfur atom of cysteine in the glutathione molecule. It’s ideal for oral ingestion because this acetyl group protects glutathione from breaking down in the gastrointestinal tract. The acetylated form of glutathione, therefore, provides optimum absorption and bioavailability.

S-acetyl glutathione not only has been shown to remain stable in the gastrointestinal tract, but it also has a longer plasma half-life with improved ability to enter cells and raise intracellular glutathione levels more efficiently. It is evidenced to cross the blood-brain barrier and is nearest in efficacy to IV glutathione than any other oral form.

Glutathione Sourcing:

Another main differentiator in the glutathione market today is sourcing. Where does the glutathione come from? This is an important question to research when comparing glutathione products since many glutathione products are sourced from China. Although some people many not have issue with this, China does not have a pristine track record when it comes to transparency and safety. Their history includes product with high levels of lead and heavy metals, unregulated manufacturing facilities and dangerous ingredients which have resulted in numerous recalls and health issues.

As of July 2011, over 60% of dietary supplement ingredients sold in the United States were imported from China. Raw materials from China are less expensive, and many companies look for ways to cut corners and increase their profit margin. The key to an excellent nutritional supplement, however, is its raw materials and quality control.

If the company cannot tell you where their raw materials are sourced, or if they have shared with you that the raw materials are from China, it is best to move on and find a company that believes in higher standards and quality.

Our Glutathione GOLD contains Emothion, a patented, crystalized form of s-acetyl glutathione sourced from Italy, which is backed by clinical studies demonstrating its efficacy. 


Available in 3 strengths, it allows for flexible dosing (100mg, 200mg and 300mg); we recommend beginning at the 100 mg dose and slowly working up from there.

We recommend taking this product (with or without food) in split dosing (For example, one capsule in the morning, one in the early afternoon)--not too close to bedtime, as it may interfere with sleep.