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In a landmark reversal, the U.S. Food & Drug Administration (FDA) has confirmed that β-Nicotinamide Mononucleotide (NMN) is lawful for use in dietary supplements in the United States. In letters issued September 29, 2025, the FDA concluded that NMN qualifies as a dietary supplement ingredient, overturning its earlier exclusion under the “drug preclusion” clause. 

A pivotal part of the agency’s reasoning was that NMN occurs naturally in the body as an intermediate in the NAD⁺ biosynthesis pathway – a scientific reality long recognized by researchers and the industry.

Why the FDA Reversed Its Decision on NMN

The deciding factor was evidence that NMN was marketed as a dietary supplement in the U.S. before any drug investigation was authorized ("pre-IND marketing"). Under FDA’s race-to-market interpretation, that means NMN is not excluded from the dietary supplement definition. This restores its lawful status in the U.S. market.

The FDA statement: 

“In light of FDA’s revised interpretation of the race-to-market clause in section 201(ff)(3)(B), we now conclude that NMN is not excluded from the definition of dietary supplement under section 201(ff)(3)(B). … NMN was marketed as a dietary supplement in the United States before such authorization.”
(Page 22, “B. Status of NMN Under Section 201(ff)(3)(B)”)

“For the reasons discussed above, we do not believe that our prior position that the dietary supplement or food must have been lawfully marketed for purposes of the race-to-market clause is the best reading of section 201(ff). … we will no longer evaluate whether the dietary supplement or food was lawfully marketed when making a determination under the race-to-market clause.”
(Page 22, “B. Status of NMN Under Section 201(ff)(3)(B)”)

“Given the way IND authorization operates under 21 CFR part 312 … it is logical to look to the authorization date of the first IND … as the relevant date for purposes of the race-to-market clause.”
(Page 11, “2. Which IND Authorization Date Is the Relevant Date”)

The fact that NMN occurs naturally in the NAD⁺ pathway provides biological context – but it was not the legal test. 

The FDA does note the biology: 

“NMN is an intermediate in nicotinamide adenine dinucleotide (NAD⁺) biosynthesis produced from nicotinamide.” (Page 5, “C. Background and Relevant Regulatory History…”)

But the legal conclusion rests on pre-IND U.S. supplement marketing and the race-to-market interpretation, as shown above.

It should be noted that…

Petitions moved the needle: Industry citizen petitions – led by the Natural Products Association (NPA) and supported by groups like ANH/CRN – challenged FDA’s prior interpretation and prompted the formal reversal.

There are still open questions: According to National Law Review, the FDA did not fully redefine how it will apply the broader “race-to-market”/drug-preclusion framework to other ingredients in the future. For now, the clarity applies squarely to NMN. 

How We Got Here: A Quick Timeline

• Nov 2022 → 2023: FDA communications stated NMN couldn’t be marketed as a dietary supplement because it had been authorized for investigation as a new drug – triggering the “drug preclusion” clause, and effectively pushing NMN off many U.S. shelves through 2023. 
• 2024: NPA’s lawsuit and citizen petition kept pressure on FDA; a federal court stay paused enforcement while FDA reviewed the petition.
• Sept 29–30, 2025: FDA reversed course, concluding NMN is not excluded from the dietary supplement definition because it was marketed as a supplement before drug investigations were authorized – restoring NMN’s status in the U.S. dietary supplement market.

Why This Matters

This is a pivotal moment for consumers, clinicians, and brands who value NAD⁺ support strategies. NAD⁺ is a helper molecule found in every cell that turns food into usable energy and supports everyday cell maintenance like DNA repair.

The FDA now recognizes what the science shows: NMN naturally plays a role in making NAD⁺, confirming its fit as a dietary supplement.

Xandro’s Take: We’ve Always Built on the Biology

The FDA’s recognition aligns policy with the science: NMN is a native NAD⁺ pathway molecule – which is why Xandro has consistently focused on purity and protocol-fit from day one. 

Read: Nicotinamide mononucleotide (NMN) research evidence

Spotlight on Xandro Pure NMN

With regulatory clarity restored, what makes Xandro Pure NMN stand out?

• It is built for High-Performance Protocols: our NMN supports recovery, cellular energy, and sustained performance for people who demand more from body and mind.
• Your Format, Your Protocol:
  • Our best-selling Pure NMN Capsules 500 mg (precision dosing for maximum efficacy, convenient)
• Pure NMN Powder 30 g (flexible dosing for custom stacks)
  
• Pure & trusted: Produced to exacting quality standards to deliver high-purity, high-consistency NMN.
  
• Certified quality: Manufactured in HACCP- and GMP-certified facilities with strict quality control across identity, purity, potency, microbials, and heavy metals.

Read: Why You Should Be Taking NMN Supplements!

Regulatory note: NMN is not intended to diagnose, treat, cure, or prevent any disease. Individuals should consult their healthcare professional before starting any new supplement regimen.

Find out more

Natural Products Association: Amid Pressure from NPA, FDA Declares NMN Lawful in Dietary Supplements

Nutraceutical Business Review: FDA reverses stance to confirm NMN is lawful for use in dietary supplements

National Law Review: FDA Determines NMN is Lawful in Dietary Supplements