FDA NAC Warning Letter: Targeting N-Acetyl Cysteine (NAC) Supplements

FDA NAC Warning Letter: Targeting N-Acetyl Cysteine (NAC) Supplements

Background on FDA NAC Warning Letters:

Navigating the FDA’s NAC system can be overwhelming. Understanding FDA warning letters is key to ensuring compliance, avoiding costly penalties and maintaining a successful business relationship with federal regulators. This guide will teach you how to understand FDA warning letters and provide guidance on how to comply.

N-acetyl-L-cysteine (NAC supplement) has been approved by the FDA to treat liver side effects from an overdose of Tylenol (acetaminophen), and to loosen the thick mucus in the lungs of people with cystic fibrosis or chronic obstructive pulmonary disease, according to a summary of the study sponsored by the Memorial Sloan Kettering Cancer Center in New York. NAC is an amino acid that was approved by the FDA as a drug in 1963. 

NAC has also been widely marketed in another category of products overseen by the FDA—dietary supplements. However, there have been several instances where the FDA has challenged the legality of NAC use in dietary supplements.

What is the FDA’s NAC System?

The FDA’s NAC system is a regulatory program that provides for the assessment of risk and imposition of requirements, restrictions and prohibitions on foods, conforming to safety standards. It includes warning letters issued by the FDA to food companies that fail to comply with the Food Safety Modernization Act (FSMA). Warning letters provide guidance on steps necessary to bring the company into compliance.

What are FDA NAC Warning Letters?

In 2010, the FDA issued a warning letter indicating that it believed that NAC was a drug and as such is not allowed to be used as an ingredient in dietary supplements. However, the FDA has still received several dietary supplement claims notifications including NAC as an ingredient tied to a structure/function claim. Up until recently, NAC had been successfully marketed as a dietary supplement product with no enforcement action.

As of recently, the FDA has issued warning letters to companies marketing dietary supplements indicated for the treatment of hangovers, as the ingredient NAC is excluded from the definition of a dietary supplement (since it was already categorized as a drug in 1963). Dietary Supplement products containing NAC are considered an unapproved drug product, and therefore illegal.

How to Identify Common Errors Before a Warning Letter is Issued?

Before you receive an FDA warning letter, it’s important to make sure your processes are compliant with FSMA requirements. By identifying common errors and taking corrective actions early on, food companies can avoid significant delays or actions resulting from a warning letter. Reviewing existing systems and practices for compliance is the first step to preventing warnings letters. Make sure all of your documentation is up-to-date and accurate, while also being able to demonstrate that all FSMA requirements are consistently met.

What are your Options Once A Warning Letter Is Received?

Once a warning letter is issued, the FDA will provide guidance on how to resolve the matter. Depending on the severity of the violation or the regulations broken, companies may have different options for remediation. These could include product recalls, facility closure plans, repackaging of products, and revising standard operating procedures. Companies should also investigate certain areas such as employee training and record keeping if an observation is related to human error. This process should be well-documented throughout in order to demonstrate that FSMA regulations have been met and corrective actions have been taken.

Creating An Effective Response To An FDA Warning Letter:

As soon as an FDA Warning Letter arrives, it needs to be addressed immediately. A comprehensive response should be sent within the prescribed timeline and include corrective actions taken or planned, along with any evidence of success or additional steps necessary to complete them. Companies should also demonstrate how current systems are in compliance with the applicable regulations and specify what measures will be implemented to ensure they remain compliant. This response must come from the appropriate personnel and be signed by a competent official, such as a Chief Compliance Officer (CCO).

Best Practices For Ongoing Compliance With The NAC System:

It’s important to create and maintain a comprehensive FDA compliance management system that can actively monitor for deficiencies that lead to issued warning letters. A CCO-driven corrective action plan should be implemented and monitored, with personnel trained on proper procedures at all levels of the organization. Procedures should also be in place for reporting any noncompliance issues quickly and accurately. Regular reviews of SOPs, GPs, document controls, quality system training, internal audit findings and policies should also take place to ensure ongoing FDA compliance.

Response from Retailers:

Amazon has recently been quietly removing dietary supplement products containing NAC from their site, shortly after the news of the FDA’s warning letters. There has also been a push by Amazon and other retailers such as Walgreens to ensure products that are being sold through their channels are compliant.

Our Experts at Quality Smart Solutions can offer support to your needs for dietary supplements, foods, cosmetics, OTC drugs and medical devices for North America.

Contact us today to learn more about how we can support your compliance needs during and after licensing!

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About the author

Kalpna Mistry
Kalpna Mistry


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