Agency clarifies NMN is not currently precluded from supplement use,
but leaves systemic barriers to innovation intact
WASHINGTON, D.C. — The Council for Responsible Nutrition (CRN), the leading trade association representing the dietary supplement and functional food industry, today expressed strong disappointment in the U.S. Food and Drug Administration’s (FDA) decision to deny CRN’s citizen petition urging the agency to correct its flawed interpretation of the drug preclusion provision under Section 201(ff)(3)(B) of the Federal Food, Drug, and Cosmetic Act and provide the industry with reasonable, fair guidance regarding the provision's application to dietary supplements.
“FDA missed a pivotal opportunity to bring clarity and balance to the line between pharmaceuticals and dietary supplements,” said Steve Mister, President & CEO, CRN. “At every juncture where FDA had the opportunity to choose between two interpretations of the statute, it chose one that favors pharmaceutical development over supplements. Consumer access to affordable and accessible healthcare products will be stymied as a result.”
What FDA decided
CRN’s May 2023 petition—and a supplemental filing in March 2025—sought a practical, common-sense framework that aligns with Congressional intent, provides regulatory certainty, and preserves consumer access to safe, beneficial supplements. While FDA clarified that NMN (nicotinamide mononucleotide) is not precluded from dietary supplement use, the agency declined to fix the underlying policies that created unnecessary uncertainty in the first place.
In its September 29 responses (to CRN and to a parallel petition from another trade group), FDA:
- Confirmed NMN’s current status: FDA clarified that NMN was marketed as a dietary supplement prior to the date that an Investigational New Drug (IND) went into effect, removing any requirement that it had to have been marketed “lawfully.”
- Reaffirmed a secretive “preclusion date”: FDA continues to treat the confidential effective date of an Investigational New Drug (IND) as the operative trigger, rather than when substantial clinical investigations for the article become public—fueling uncertainty for supplement innovators.
- Appears to have broadened “substantial clinical investigations”: The agency response indicates that even early-phase or limited studies can confer drug companies with a monopoly for an ingredient if FDA deems them qualitatively important for drug development. CRN had sought clear delineation from FDA for what constitutes a “substantial” investigation. Basically, FDA claims it will know it when it sees it.
- Limited marketing evidence to the U.S.: FDA rejected foreign marketing of an ingredient as either a food or a supplement as relevant to the race-to-market, even though it puts drug companies on notice of supplement interest in an ingredient. Drug companies may seize on articles marketed elsewhere before they are marketed in the U.S. and prevent their sale as a supplement here.
- Acknowledged one narrow point: “Marketing” need not be “legal” to count—but this technical concession offers little practical relief for most ingredients.
- Declined guidance or rulemaking: FDA again refused to issue interpretive guidance or initiate rulemaking to create reasonable exceptions, citing the need to allocate the agency’s limited resources to “priority matters.”
“The agency’s reliance on non-public IND dates and an expansive view of ‘substantial clinical investigations’ creates a moving target that businesses cannot reliably plan around,” said Megan Olsen, Senior Vice President and General Counsel, CRN. “Yes, FDA now says that NMN is not drug precluded. But the same unstable framework remains in place for the next ingredient, inviting repeat uncertainty.”
Why CRN is disappointed
Although FDA’s clarification on NMN resolves the immediate question for that specific ingredient, the decision fails to address the core structural problems that sparked the NMN confusion to begin with. By preserving secret IND triggers, U.S.-only marketing rules, and vague criteria for “substantial” investigations—without guidance or rulemaking—FDA keeps the industry in a cloud of ambiguity, stifling innovation and risking future consumer access when promising dietary ingredients enter the marketplace.
“Collectively, FDA’s response does one thing: it allows FDA to dodge the bullet with respect to NMN and escape a potential legal battle over its status,” Mister added. “But FDA has aggressively declined to provide any real guidance to the supplement or pharmaceutical industries. Without transparent, publicly knowable triggers and workable guidance, companies will continue to face unnecessary conflict with drug development rather than a coherent policy that advances public health.”
What should happen next
CRN urges FDA to revisit its interpretation and issue clear guidance—or, if the agency will not act, for Congress to restore balance so that consumers retain access to beneficial supplements while legitimate drug innovation proceeds.
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About CRN
The Council for Responsible Nutrition (CRN), founded in 1973, is a Washington, D.C.-based trade association representing 180+ dietary supplement and functional food manufacturers, ingredient suppliers, and companies providing services to those manufacturers and suppliers. In addition to complying with a host of federal and state regulations governing dietary supplements and food in the areas of manufacturing, marketing, quality control and safety, our manufacturer and supplier members also agree to adhere to additional voluntary guidelines as well as to CRN’s Code of Ethics.
CONTACT:
Jeff Ventura
Vice President, Communications
Council for Responsible Nutrition
1828 L Street, NW, Suite 220
Washington, D.C. 20036
(202) 204-7680 / (202) 851-1334 (cell)
jventura@crnusa.org