Evidence explainerNMN (nicotinamide mononucleotide)
Is NMN Legal in the US? FDA Reversed Its 2022 Position on September 29, 2025
For three years FDA held that NMN could not be sold as a supplement. In September 2025 it changed its reading of the law. Here is the timeline, and what the decision does and does not mean.
Key takeaways
- On October 11, 2022, FDA told an NMN notifier that NMN was excluded from the dietary-supplement definition [1].
- On March 6, 2023, the Natural Products Association and the Alliance for Natural Health USA petitioned FDA to reconsider [1].
- On September 29, 2025, FDA responded and concluded that NMN is not excluded from the dietary-supplement definition [1].
- A December 2, 2025 FDA letter set aside the 2022 letters and acknowledged a notification for NMN at up to 400 mg a day [1].
- FDA says that acknowledgement is procedural and is not a finding that NMN is safe [1].
Safety at a glance
From our NMN (nicotinamide mononucleotide) monograph. Published interactions and cautions only, each with its source.
Who should be careful
- Long-term use. Trials lasted 24 weeks at most; long-term safety has not been established.[5]
- Regulatory note. FDA's acknowledgement of an NMN notification is procedural and is not a finding that NMN or products containing it are safe.[1]
- Before you start. Talk to your pharmacist or clinician before adding this supplement, especially if you take prescription medicines, are pregnant or breastfeeding, or have a chronic health condition.[5]
The evidence, graded
Pulled from our monograph evidence tables. Grades follow our evidence-grading policy.
- Grade CImprovedBlood NAD and six-minute walking distanceBlood NAD rose in all NMN groups versus placebo. Six-minute walking distance increased more with all doses than placebo, most with 600 and 900 mg. HOMA-IR did not differ from placebo, and NMN was well tolerated.
- Grade CNo effectFasting glucose, insulin, HbA1c and lipidsNMN showed no significant benefit on fasting glucose, fasting insulin, HbA1c, HOMA-IR or the lipid profile.
The timeline
Key dates from FDA's December 2025 letter on new dietary ingredient notification 1259 [1]:
- July 28, 2022: FDA filed a notification for NMN as a new dietary ingredient [1].
- October 11, 2022: FDA replied that NMN was excluded from the dietary-supplement definition, its position at the time; a supplemental letter followed on November 4, 2022 [1].
- March 6, 2023: two industry groups filed a citizen petition asking FDA to reconsider [1].
- September 29, 2025: FDA answered the petition, changed its interpretation of one part of the law and concluded NMN is not excluded [1].
- December 2, 2025: FDA set aside its 2022 letters and acknowledged the notification [1].
Why NMN was excluded in 2022
FDA's 2022 letter relied on the clause of the law that excludes articles authorized for investigation as new drugs, with substantial clinical investigations made public, before being marketed as supplements or foods [1][2]. In 2025 FDA said it had reconsidered one aspect of that part of the law, and NMN is therefore not excluded [1].
What the 2025 decision does and does not mean
The notification FDA acknowledged describes products for adults as tablets, capsules or powders at no more than 400 mg of NMN per day [1]. That limit comes from the manufacturer's notification, not from an FDA dose recommendation [1].
FDA says acceptance of the notification for filing is a procedural matter and is not a finding that NMN, or a product containing it, is safe or not adulterated; it can still act against unsafe or misbranded products [1].
On safety, a 2026 meta-analysis of 15 trials using 250 to 2,000 mg/day for 14 days to 24 weeks found no increase in adverse events or liver enzymes, while noting that longer trials are needed [3]. For the benefit evidence, read does NMN work.
Quick answers
Is NMN FDA approved?
No. FDA's December 2025 letter acknowledges a new dietary ingredient notification, which FDA calls a procedural matter, not a safety finding [1].
Keep reading
Full monographs
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References
- [1]Letter on NDIN 1259 (beta-nicotinamide mononucleotide), December 2, 2025. U.S. Food and Drug Administration, 2025.
- [2]Guidance for Industry: Policy Regarding N-acetyl-L-cysteine. U.S. Food and Drug Administration, 2022.
- [3]Safety and Metabolism-Related Outcomes of Oral Nicotinamide Mononucleotide Supplementation in Adults: A Systematic Review and Meta-Analysis. Nutrients, 2026.