What is NAC?

By Noah Whitaker | August 16, 2023

Today we are going to discuss an amazing and somewhat controversial supplement, at least in the eyes of the FDA, N-acetyl-cysteine or NAC.

It is a more stable form of cysteine which is an amino acid found in all protein foods.  However, due to some of the recent news around this powerful ingredient, there may be some who are fearful to use this product. 

Interestingly, NAC was approved by the FDA as a respiratory drug for chronic bronchitis in 1963 and has been used to treat patients who have overdosed from acetaminophen since 1980. 

It has also been used as a dietary supplement to help with liver issues, kidney problems, neurologic damage, brain health, fertility and immune health since the 1990’s and was allowed to do so due to its safety profile. 

However, in 2010 the FDA began working to take this ingredient off the market which really heightened during COVID when NAC was found in studies to have some use in fighting off COVID-19. 

For NAC, and other ingredients with confusing legality like CBD, nothing is black and white. Unlike drugs, there is no approval process for dietary supplements. They are regulated by the FDA but not approved. 

If a supplement contains dietary ingredients that were either already used in supplements before DSHEA (1994), or established as reasonably safe since then, it can be lawfully sold to consumers.

Those in the dietary supplement industry claim that there is no reason for the FDA to take retroactive steps to remove products that have been available for years with no clear safety issues. They are also concerned that this could open the door for the FDA to make the same determination about other products, such as fish oil and vitamin K, which is a story for another day. 

This is certainly a concern for hundreds of thousands of individuals who have received great benefit from NAC and we hope the FDA takes a different direction with these ingredients.

The Benefits of NAC

Since we have no control over what the FDA does, we should take advantage of the benefits of NAC and learn as much as possible about its benefits while we still can. 

We have already discussed the use of NAC being a prescription product for use as a mucolytic, meaning it just thins the mucus in the lungs and makes it easier to clear mucus from your lungs, and it has also been used as an antidote for Tylenol/ acetaminophen poisoning.[i]   

Potential health benefits of NAC include the following:

  • Helps produce antioxidants
  • Helps prevent kidney and liver damage
  • May improve mental health conditions and substance use disorder
  • Relieves symptoms of respiratory conditions
  • Boosts brain health
  • May improve fertility in all genders
  • Stabilizes blood sugar
  • Reduces the risk of heart disease
  • Boosts immune function
  • Reduces the risk of preterm birth and recurrent pregnancy loss

People who should avoid taking NAC include those with the following conditions:

  • Asthma
  • Bleeding problems
  • Pregnant women
  • Breastfeeding women
  • Undergoing any elective surgery (at least for two weeks before surgery)

NAC can also interact with certain medications, including:

An excessive amount of N-acetyl cysteine (NAC) can cause side effects such as:

I hope this helps you learn a little more about NAC and its benefits!

[i] Smaga, I., et. al. N-acetylcysteine as a New Prominent Approach for Treating Psychiatric Disorders.  British Pharmacological Sociey.  March 14, 2021. P 2569-2594.

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