If you’ve been staying on top of your wellness game, you’re probably familiar with the concept of antioxidants and the positive role they can play in your health. Research suggests antioxidants support everything from cognition to metabolic function to joint health. The more commonly known antioxidants (namely vitamins A, C, and, E) are found in many of the foods we eat, but they are just a few of the myriad lesser-known—but nevertheless important—antioxidant nutrients. One that’s been getting some buzz lately is NAC, or n-acetyl l-cysteine.

What is NAC? 

NAC is a supplement form of the amino acid l-cysteine, which allows for the production of glutathione, the most powerful antioxidant in the body, explains naturopathic doctor and clinical nutritionist David Friedman, N.D., D.C. 

“Cysteine is a naturally-occurring, sulfur-containing amino acid found in small quantities in most proteins, including turkey, chicken, fish, cheese, yogurt, eggs, sunflower seeds, and legumes,” he says. “Individuals who have high blood sugar or blood pressure, for example, have a hard time keeping up with cysteine production. In cases like these, the supplement form of the amino can come in handy.” 

Research suggests NAC can also be helpful for aging individuals who have low glutathione levels, those with poor nutrition, and those living sedentary lifestyles.

The benefits of NAC

Like other antioxidants, NAC combats oxidative stress caused by free radicals. Here’s a closer look at some of the ways n-acetyl-l-cysteine may benefit your health.

1. immunity

NAC has received much attention lately because of its immune-boosting properties.

Read More: Are You Unconsciously Hurting Your Immune System?

“On August 11, 2020, The Federation of American Societies for Experimental Biology published a paper suggesting that NAC may be helpful amidst COVID-19,” notes Friedman. It’s also generally accepted to be a highly-tolerated way to promote a healthy immune system.

2. lung health

Toronto-based naturopathic doctor Olivia Rose, N.D., recommends NAC supplementation to her patients looking to promote healthy lungs. “It supports the health of lung tissues, helps thin mucus, and promotes overall lung function,” she says. 

One study published in the journal Multidisciplinary Respiratory Medicine found that people with chronic obstructive pulmonary disease (COPD) who took 600 milligrams of NAC twice daily experienced lung function benefits.

3. mental health 

Research, including one 2018 study published in BioMed Research International, suggests NAC may be effective in supporting people with various mental health concerns. That said, it’s important to consult your primary care provider before taking n-acetyl l-cysteine to support mental well-being. The supplement may interfere with certain medications.  

4. fertility

Add n-acetyl l-cysteine to the list of nutrients that may help support fertility. “One study published in the journal Reproductive Biology and Endocrinology found that NAC may promote healthy sperm counts and motility,” says Rose. 

Read More: 10 Ways Women Can Support Their Fertility Naturally

Is NAC Right For You?

Despite its many benefits, NAC supplementation is not for everyone. People with bleeding disorders and those on blood thinners shouldn’t take it, as it may slow blood clotting, warns Friedman. 

“NAC may be most helpful for patients looking to stabilize blood sugar, improve insulin resistance, or promote balance in the body,” he says. “Most importantly, though, emerging data suggests NAC’s antioxidant properties may benefit anyone interested in boosting their immune system right now.”

How To Supplement With NAC

While there are no universal guidelines on supplementation, amounts up to 1,200 milligrams per day (generally taken in divided doses) are common, according to Friedman. (The Vitamin Shoppe brand’s NAC contains 600 milligrams of n-acetyl-l-cysteine.) 

“Side effects are rare,” he says. “But taking above 3,000 milligrams per day may cause headache, vomiting, abdominal pain, diarrhea, and constipation,” he says.

Consult with your primary care physician for an individualized recommendation.