Highlights

  • In their lawsuit, the Natural Products Association (NPA) requested a ruling that the Food and Drug Administration (FDA) not exclude NMN from being defined as a dietary supplement.
  • The NMN supplement market has suffered a detrimental downturn in the US following an FDA ruling banning the sale of NMN in 2022.
  • According to NPA lawyers, the NMN industry will continue challenging FDA rulings when warranted.

The NPA, a Washington, D.C.-based trade association that represents retailers and manufacturers of dietary supplements, has sued the FDA over its ban of the sale of NMN, based on a ruling from 2022. This new development occurred on August 28, 2024, when the NPA filed a complaint in the US District Court for the District of Columbia against the FDA, the US Department of Health and Human Services (HHS), and the directors of both agencies.

A Lawsuit Requesting NMN Not Be Excluded from the Definition of a Supplement

In their lawsuit, the NPA requested a declaration from the courts that NMN should not be excluded from the definition of a dietary supplement. The lawsuit may have an impact not just for vendors selling NMN but also on a pharmaceutical company that has been using NMN for clinical trials, using a proprietary NMN-based ingredient called MIB-626.

Along those lines, a company that Dr. David Sinclair—a Harvard University-based genetics professor and aging expert—co-founded called Metro International Biotech LLC started using MIB-626 for human trial testing in 2022. In that regard, an investigational new drug (IND) application pertaining to Metro International Biotech’s MIB-626 propelled the FDA’s decision that NMN cannot be marketed in dietary supplement products.

As such, the FDA’s ruling against the sale of NMN caught the NMN industry off-guard, especially since the FDA had previously been made aware of efforts to market NMN. What’s more, the FDA, without objection, even acknowledged NMN with a new dietary ingredient notification (NDIN)—a designation allowing the sale of the supplement. The FDA filed the notification for NMN in response to SyncoZymes (Co.) Ltd. on March 21, 2021.

The date of this notification is paramount. Under the FDA’s interpretation of the law, if vendors sold NMN as a dietary supplement with an NDIN before its authorization for investigation as an IND, they can continue to market NMN in supplements. The FDA, on the other hand, ended up concluding that NMN was excluded from the definition of a dietary supplement, “based on new information that came to light,” while reviewing Metro International Biotech’s IND notification.

Thus, in a November 4, 2022 letter to a representative from an NMN vendor, Inner Mongolia Kingdomway Pharmaceutical Ltd., the FDA wrote, “After carefully reviewing the information provided in your amended notification and other relevant sources, including our own records, we also concluded that NMN was not marketed as a dietary supplement, except unlawfully without an NDI notification, or as a food before FDA authorized it for investigation as a new drug.”

Since blindsiding the NMN industry with that letter, the market for NMN has suffered substantial setbacks. For example, Amazon announced in 2023 that it would no longer allow companies to sell NMN via its platform. Similarly, PayPal and Shopify payment processors stopped the sale of NMN, according to the NPA’s 47-page lawsuit.

A Substantive Ruling Could Re-Initiate the Sale of NMN in the US

This substantive ruling in this case could re-initiate the sale of NMN in the US, and it draws into question how the FDA applies its drug exclusion clause of the Dietary Supplement Health and Education Act of 1994 (DSHEA). This clause bars the marketing of ingredients first approved as a drug or first authorized for investigation as a new drug, which are under “substantial clinical investigations” that have been made public. The application of this clause came on the heels of the FDA’s NDIN that essentially acknowledged the marketing and sale of NMN. In that regard, the FDA rescinded their NDIN designation of NMN with their letter to Inner Mongolia Kingdomway Pharmaceutical Ltd. in November, 2022.

Moreover, the FDA has yet to substantively respond to a citizen petition filed by the NPA in March 2023 regarding the FDA’s ruling on NMN. That petition requested that the FDA not exclude NMN from the definition of a dietary supplement or commit to exercise enforcement discretion pertaining to the selling of NMN.

Then, in August 2023, the FDA advised that it had not reached a decision pertaining to NMN “due to competing agency priorities.” Also in response to the petition, Metro International Biotech requested that the FDA uphold its ruling that NMN is excluded from the definition of a dietary supplement and cannot be marketed in supplement products.

“FDA has shown it will seek to enforce its conclusion on NMN and improperly detain NMN while intentionally refusing to respond to NPA’s citizen’s petition,” stated the NPA in their lawsuit. “This is not an issue that will resolve itself absent judicial intervention.”

The Supplement Industry Plans to Continue Pressing the FDA

One of the lawyers representing the NPA, Kevin M. Bell, has emphasized the importance of the lawsuit against the FDA. In a press release, he commented that the supplement industry will challenge and respond to the FDA when it takes actions or inactions like those associated with their determination regarding NMN.

“I think there is a history of this industry not challenging FDA’s positions,” says Bell. “When you do something that harms our industry that we disagree with, that we think is legally incorrect, we’re going to start challenging [FDA]. You see it on the drug side all the time. You rarely see it on the food/supplement side.”

The NPA President and CEO, Daniel Fabricant, PhD, also suggested that the FDA is unwilling to have any fruitful discussions to resolve disagreements with the supplement industry “in a timely and reasonable manner.” He also commented that after receiving the FDA’s NDIN regarding NMN, the FDA then rescinded their determination, which has never happened before.

Dr. Fabricant continued that the case has significance not only because NMN is an important supplement for the nutraceutical industry but also because the FDA’s ruling has harmed the new dietary ingredient notification process. As such, if a new supplement receives an NDIN, the possibility looms that the FDA can also rescind that NDIN.

US Consumers May Not Have the Option to Purchase NMN for the Foreseeable Future

It appears that the FDA’s determination that NMN does not fall under the definition of a dietary supplement has produced somewhat of a legal quagmire. If the NPA’s lawsuit generates a ruling to classify NMN as a supplement, vendors will likely race to return this nutraceutical to the US market.

On the other hand, if the courts toss out the lawsuit, US consumers may not have the option of purchasing NMN until Metro International Biotech produces their NMN-based drug. Even then, we are still left with the question of what the data regarding Metro’s MIB-626 NMN-based drug looks like. Accordingly, the tantalizing results proving or disproving MIB-626’s efficacy remain to be seen.