N-Acetyl-L-Cysteine Supports Detoxification, Skin Health, Immune Function & More*

In recent years, the term "detox" has become synonymous with "cleanse"—i.e., something you do occasionally and temporarily. But here's the thing: Detoxification simply doesn't work that way. 

Thanks to your body's hardworking organs and complex antioxidant networks, detoxification is a natural, built-in process that takes place all day, every day—no special "detox diets" necessary.

That said, if you want to support and optimize your body's intrinsic cleanup crew, it's helpful to focus on your daily nutrition choices. This includes what you eat and drink, of course, as well as your personalized supplement lineup. 

For example, mbg's daily detox+ is led by glutathione (a master antioxidant in the realm of detox support) and also contains N-acetyl-L-cysteine—a vital player in the detoxification process that replenishes antioxidants in the body to promote healthy redox balance.*

N-acetyl-L-cysteine (NAC) is the precursor for cysteine, a nonessential amino acid. (In case you need a refresher, amino acids are the building blocks of proteins throughout your body. Essential amino acids can't be made by the body, so you need to get them from food. In contrast, nonessential amino acids can be produced by the body, even if your diet doesn't include all of them.) 

Cysteine is also known as "semi-essential" or "conditionally essential," as it can become essential in certain situations, explains Paula Doebrich, MPH, RDN, registered dietitian nutritionist and founder of Happea Nutrition.

In the body, cysteine is used to make glutathione—a powerful, whole-body-relevant antioxidant involved in fighting free radicals, maintaining tissue integrity, and strengthening immune function, notes Doebrich.* NAC itself can also help replenish glutathione1, as it's a stellar source of sulfhydryl groups, which convert into metabolites that promote glutathione synthesis.*

When it comes to your body's intrinsic detoxification pathways, your liver is considered the head honcho. Case in point: One of its main roles is to remove waste and toxins5 from your body. To do this, the liver coordinates an elaborate detoxification enzyme system featuring a series of cellular processes. NAC is highly active in phase II detox pathways, making it an important player in the liver's detox actions.*

The antioxidant properties of NAC and glutathione support overall liver function, and ultimately, detoxification.* mbg's vice president of scientific affairs, Ashley Jordan Ferira, Ph.D., RDN, dives deeper: "Metabolically active organs like the liver are generating lots of oxidant byproducts, like free radicals. Indeed, the liver is the body's primary detoxifying organ, so it's busy 24/7. As a source of sulfhydryl groups, NAC is considered a fast-acting antioxidant that helps neutralize oxidants in the liver and in other 'busy' organs. Indeed, NAC and compounds that NAC helps directly replenish (hello, glutathione) are boots-on-the-ground scavengers of those oxidants, supporting the resilience and repair of our liver cells and tissue,"* she explains. 

Although the liver is the captain of your body's detoxification system, other organs help steer the ship. This includes the skin, which is a physical barrier7 against unwanted compounds like pollutants, toxins, and byproducts of daily biological processes. And while oxidative stress can affect the skin's natural defense system, the antioxidant actions of NAC and glutathione help support skin health8 by nurturing overall redox balance.*

"NAC has antioxidant and anti-inflammatory properties, [so] it can aid the immune system,"* shares Doebrich. Engler explains further: "Your immune system is constantly working to support your body through environmental stressors, but also, everyday biological processes that produce oxidant byproducts that can contribute to oxidative stress. Effective antioxidants—such as NAC—have the power to quench these byproducts (like free radicals), thus combating oxidative stress and supporting immune function at the cellular level. NAC provides support of healthy antioxidant-versus-oxidant balance in the body, helping the immune system function optimally but also providing whole-body benefit.”*

The brain is highly susceptible to oxidative stress10, but prioritizing your body's antioxidant levels can protect it for years to come. Enter: The antioxidant abilities of NAC and glutathione, which can help protect nerve cells (and therefore, nerve function) by quelling oxidative stress.* 

Due to its role in glutathione synthesis, NAC may even help maintain well-balanced emotions. For starters, glutathione is one of the most important antioxidants in the brain, where it protects critical cells and tissues from oxidative stress.* 

As NAC supports the production of glutathione, it can also support healthy body composition.* It's all thanks to—you guessed it—the antioxidant properties of glutathione.

Before diving into the ideal NAC dosage, let's chat about form: "For oral dietary supplement applications, there is no research that indicates NAC in a capsule versus powder, gelcap, or tablet would act any differently. I personally find gummy delivery formats of NAC to be a tad paradoxical, given that NAC is fighting oxidants and the sugars in gummies are, well, not!" says Ferira.

She expounds further: "Unlike vitamins, minerals, and some key phytonutrients, the question of ideal dosage for a bioactive like NAC is not a straightforward or easy one. Not because there aren't studies (there are) but because the answer of NAC dose completely depends on the person's health status and targeted health support needs. What we do know is that a sub-efficacious sprinkling of NAC (e.g., less than 100 milligrams per serving) is likely not exerting potent antioxidant effects."

In a compelling clinical study9 from Free Radical Biology and Medicine examining the effects of NAC, a 600-milligram dose improved parameters of immune function.* Likewise, a daily NAC intake of 600 milligrams has been clinically shown to positively affect overall nutritional and antioxidant status.*

"For this reason, I prefer NAC supplements 'playing ball' in the 500-milligram-plus range," notes Ferira. "This science also directly supported the full-potency 600-milligram dose of NAC you'll find in mbg's daily detox+."

"NAC at higher doses, for specific indications, has also been researched. For example: NAC's ability to reduce homocysteine (i.e., a majorly important biomarker for cardiovascular health but also for whole-body methylation functions), as well as its blood-pressure-lowering benefits, have been clinically shown14 to occur at 1.8 grams (1,800 milligrams) of NAC supplementation,"* shares Ferira. "Also, at higher doses (i.e., again, several grams), NAC may help with athletic performance, but that research15 is equivocal and needs to shake out a bit more."* 

Finally, "in other clinical scenarios16 related to pulmonary function and mental health, higher NAC doses (at and above 2 grams) have also shown utility and promise when partnered with a health care practitioner to create a personalized regimen,"* says Ferira. 

Now, if you're unsure whether to take NAC morning or night, Engler has the answer: "There isn't an ideal time of day to take NAC. Though, some choose to leverage its detoxifying and other whole-body benefits first thing in the morning on an empty stomach or with their breakfast."* That's totally up to you!

NAC is a key building block precursor for several antioxidants, including "master antioxidant" glutathione. NAC itself boasts major antioxidant properties, as it works to scavenge free radicals and improve our redox status for cellular protection and longevity.* These actions translate to 360-degree support for liver detoxification, skin health, immune function, brain health, mood, and healthy weight maintenance.*