Legal status · United Kingdom
Is MIB-626 legal in the United Kingdom?
Written by Aaron CuhaReviewed Sep 2026
Direct answer
No. MIB-626 is not approved for any medical use in the United Kingdom; its classification is "Investigational, not licensed". Lawful access is limited to registered clinical trials. "Research use only" labeling on vials sold online does not make human use lawful. On the evidence, 4 human studies are cited on its profile.
MIB-626 in the United Kingdom at a glance
| Classification | Investigational, not licensed |
|---|---|
| Note | Investigational. No MHRA authorisation. |
| MHRA approval status | Not approved by MHRA; investigational |
| Human studies cited | 4 of 4 citations on the profile |
| Reviewed | Sep 2026 |
Classification and note come from the MIB-626 profile, checked against Medicines and Healthcare products Regulatory Agency (MHRA) listings at the reviewed date.
What this means
- 01
MIB-626 is being studied in registered clinical trials but has not received MHRA marketing approval in the United Kingdom.
- 02
Lawful human access is limited to trial participation or a formal early-access scheme where one exists; there is no pharmacy product to prescribe.
- 03
Vials sold online "for research use only" are not trial material, and that label does not make human use lawful.
What MIB-626 is
The only NMN product with a real randomised trial programme: three placebo-controlled trials totalling about 104 participants, all of which measured blood NAD and safety. It raised blood NAD substantially every time. It did not change muscle strength, aerobic capacity, insulin sensitivity, liver fat, or any marker of kidney injury or inflammation in hospitalised patients.
MIB-626 is beta-nicotinamide mononucleotide. The molecule is the same one sold in supplement capsules.
Mechanism: The active molecule is beta-nicotinamide mononucleotide, which enters NAD synthesis one step below nicotinamide riboside: NMN is adenylylated by NMNAT enzymes directly to NAD, bypassing the NAMPT step that limits nicotinamide. The proprietary element is formulation rather than pharmacology, a defined microcrystalline polymorph intended to give reproducible, pharmaceutical-grade exposure, which is what allows dose-ranging and regulatory filing in a way a variable supplement powder does not.
Regulatory history: An investigational drug in the United States, developed under an IND by Metro International Biotech. It is not approved for any indication and is not the same regulatory object as NMN sold as a dietary supplement, although the molecule is identical. The existence of that IND is what triggered FDA's 2022 determination excluding NMN from the dietary supplement definition, a determination FDA reversed in September 2025.
How MHRA treats this kind of product
Licenses medicines for the UK market. A compound without a marketing authorisation is an unlicensed medicine, which can only lawfully be supplied for human use through a prescriber under the specials scheme, not sold as a research product.
The classification above is the The Longevity Archive reading of Medicines and Healthcare products Regulatory Agency listings for MIB-626 at the reviewed date, not a legal opinion. Rules change, and importing, prescribing and possessing a compound can each be treated differently. Check the regulator directly before acting on anything here.
MIB-626 in other countries
Frequently asked questions
Is MIB-626 legal in the United Kingdom?
No. MIB-626 is not approved for any medical use in the United Kingdom; its classification is "Investigational, not licensed". Lawful access is limited to registered clinical trials. "Research use only" labeling on vials sold online does not make human use lawful. On the evidence, 4 human studies are cited on its profile. Note: Investigational. No MHRA authorisation.
Can I buy MIB-626 in the United Kingdom?
No approved product exists to buy. In the United Kingdom MIB-626 is classified as "Investigational, not licensed", so there is no licensed pharmacy product. Vendors selling it "for research use only" are not selling it for human use, and that label does not change its legal status. This site does not list or recommend vendors. Note: Investigational. No MHRA authorisation.
Is MIB-626 MHRA approved?
No. In the United Kingdom MIB-626 is classified as "Investigational, not licensed", which is not a MHRA marketing approval. For comparison, the US FDA status is: An investigational drug in the United States, developed under an IND by Metro International Biotech. It is not approved for any indication and is not the same regulatory object as NMN sold as a dietary supplement, although the molecule is identical. The existence of that IND is what triggered FDA's 2022 determination excluding NMN from the dietary supplement definition, a determination FDA reversed in September 2025.. On the evidence, 4 human studies are cited on its profile.
Related compounds in the United Kingdom
Full research profile
Mechanism, cited studies, FDA status and the full legal summary for MIB-626 live on its compound profile.
MIB-626 profileThis page is general information about the regulatory status of MIB-626 in the United Kingdom, current as of Sep 2026. It is not legal advice, and classifications change; check Medicines and Healthcare products Regulatory Agency directly or consult a lawyer for a specific situation. Educational use only. This database summarizes published research. It is not medical advice and contains no dosing protocols or recommendations for personal use. The Longevity Archive has no vendor relationships and does not recommend where to buy anything.