Is MIB-626 legal in the United States?

The only NMN product with a real set of studies in people: three studies with a dummy pill group, about 104 people in all. All three measured blood NAD and safety. It raised blood NAD a lot every time. It did not change muscle strength, fitness, how well insulin works or liver fat. In hospital patients, it did not change any marker of kidney damage or inflammation.

MIB-626 is NMN, the same molecule sold in supplement capsules. What Metro International Biotech made is one specific crystal form of it.

How it works: The active molecule is NMN. The body turns NMN straight into NAD in one step.

Approval history: An investigational drug in the United States. Metro International Biotech is developing it under an FDA permit to test it in people (an IND). It is not approved for any use. It is the same molecule as NMN sold as a supplement, but the law treats it as a different product. That IND is what led the FDA in 2022 to rule that NMN could not be sold as a supplement. The FDA reversed that ruling in September 2025.

Approves prescription drugs, each for a named use. It also acts against unapproved products, including peptides sold online. Compounding pharmacies, which mix drugs to order, may make some compounds with a prescription. That only applies when the FDA puts the compound in a category of bulk ingredients it allows.

The legal category above is how The Longevity Archive reads U.S. Food and Drug Administration listings for MIB-626 on the reviewed date. It is not a legal opinion. Rules change. Bringing a compound into the country, prescribing it and owning it can each be treated differently. Check with the agency before you act on anything here.

Check FDA directly

Whether MIB-626 is banned in sport is set by the World Anti-Doping Code and by military rules, not by its legal status in the United States. Before you compete or get tested, look up MIB-626 by name on the Prohibited List, or look up a named product in Global DRO. Under the World Anti-Doping Code, category S0 bans, at all times, any drug-like substance that meets two tests. No other section of the List covers it. And no government health regulator anywhere has a current approval for it as a treatment in people. Many substances that are approved somewhere are banned by name in another section. So approval does not mean a substance is allowed in sport.

• WADA Prohibited List
• Global DRO (check a named product)
• USADA (US athletes)
• Operation Supplement Safety (US service members)

The rules you compete or serve under decide this, not this page.