MIB-626 dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
MIB-626 is the only NMN product with a real set of studies in people: three studies with a dummy pill group, about 104 people in all.
Evidence grade for MIB-626: Moderate. The rule: at least one finished study in people, and at least 100 people who took it. The sum on this page: 4 completed trials, 107 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 107
- Human studies
- 4
- Found nothing
- 2
Dose
No human dose established
Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose.
4 completed trials, 107 people given it
1 effects reported, 1 unwanted, by people using it, not a trial
Goal pages: Fat loss and metabolism, Muscle and strength, Ageing and longevity, Injury, healing and recovery, Heart and circulation, Immune system and inflammation, Gut health
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
MIB-626 is a drug-grade form of NMN, the NAD booster sold as a supplement. The molecule is the same. The company made one exact crystal form and tested it like a drug. It is not approved and not for sale.
What people take it for
- Raising NAD in the blood.
- Staying healthier with age.
- Losing weight and improving cholesterol.
What studies in people showed
Three small studies, about 104 people in all, each with a dummy pill group. It raised blood NAD every time. In 42 hospital patients with COVID and kidney injury, blood NAD nearly tripled. Their kidneys and inflammation did not change. In 30 overweight adults over 28 days, weight fell 1.9 kg and cholesterol fell. Strength, fitness, liver fat and how well insulin worked did not change. The maker helped pay for two of the studies.
What people report
Reports, not study results
The good
- We have not collected user reports. It is not sold, so there are none to collect.
The bad
- The studies found no safety problems, but nobody has taken it for longer than 28 days.
Where these come from: It is not sold, so there are no user reports. These lines come from the studies on this page.
My bottom line
It raises a blood number and has not changed anything you would feel. Good science and honest reporting, but no payoff yet. Save your money.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals MIB-626 has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Gut and digestion65 people · 1 study
- Cell energy and mitochondria42 people · 2 studies · 1 found nothing
- Inflammation42 people · 1 study · 1 found nothing
- Kidney function42 people · 1 study · 1 found nothing
- Losing weightno headcount stated · 1 study · 1 found nothing
- Losing fat specificallyno headcount stated · 1 study · 1 found nothing
- Getting strongerno headcount stated · 1 study · 1 found nothing
- Lasting longer, staminano headcount stated · 1 study · 1 found nothing
- Blood sugar and insulinno headcount stated · 1 study · 1 found nothing
- Cholesterol and blood fatsno headcount stated · 1 study · 1 found nothing
- Liver fat and liver healthno headcount stated · 1 study · 1 found nothing
- Blood pressureno headcount stated · 1 study · 1 found nothing
24 of the 36 indexed goals have no study of any kind behind MIB-626
No study in people, animals or cells on this page reports a result for these. That does not prove MIB-626 does nothing for them. It does mean anything you have heard about MIB-626 and one of these did not come from a study cited here.
Show full evidence
What is MIB-626?
MIB-626 is 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. The company took it through the drug approval path, with proper studies attached. That is unusual in this field. It is why this product gets its own page rather than a line on the NMN page.
The studies have produced what serious early drug research produces, and no more. The first gave 32 overweight or obese adults aged 55 to 80 either 1000 mg once or twice a day, or a dummy pill, for 14 days. Blood NMN rose clearly above the dummy group. Across the day, the total was 1.7 times and 3.7 times the starting level for the two schedules. Blood NAD rose a lot, more on the bigger dose. Very little NMN came out in the urine unchanged.
The second study is the one usually called a win. 30 overweight or obese adults aged 45 and up took 1000 mg twice a day for 28 days. Weight fell 1.9 kg. The lower blood pressure number fell 7.01 mmHg. Total cholesterol fell 26.89 mg/dL, and bad cholesterol fell 18.73 mg/dL. In the same study, muscle strength, how fast muscles tired, fitness and stair-climbing power did not change. How well insulin worked, liver fat and belly fat did not change in either group. Metro International Biotech helped pay for it.
The third study tells you the most and gets quoted the least. 42 adults in hospital with COVID-19 and sudden kidney injury took 1.0 g of MIB-626 twice a day, or a dummy pill, for 14 days. Blood NAD rose from about 16 to about 43 micrograms per millilitre by day 14. That is a big, clearly shown chemical effect. Kidney blood tests, kidney damage markers, inflammation markers and how sick people were did not differ between the groups. That is the whole pattern of this category in one study.
How does MIB-626 work?
The active molecule is NMN. The body turns NMN straight into NAD in one step. That skips NAMPT, the slow step that holds back nicotinamide. What the company owns is the form, not the chemistry. It is one defined crystal form, meant to give the same dose every time, like a real drug. That is what makes dose testing and drug filings possible in a way a variable supplement powder does not. A 2026 study in people raised another possibility. NMN and NR swallowed by mouth may raise NAD partly because gut bacteria turn them into niacin. If that is right, it applies to this product as much as to any other NMN pill.
What have studies in people found about MIB-626?
Three studies with a dummy pill group, about 104 people in all. All three measured blood NAD and safety. Two also measured body or health results, and those mostly did not change.
- COVID-19 with sudden kidney injury, 42 people, 14 days at 1.0 g twice a day: blood NAD rose from 16.0 to 42.6 micrograms per millilitre. Kidney blood tests, kidney damage markers, inflammation markers and how sick people were did not change compared with the dummy pill.
- Blood levels study, 32 adults aged 55 to 80, 14 days at 1000 mg once or twice a day: blood NMN across the day rose 1.7 times and 3.7 times over the start, and blood NAD rose a lot, more on the bigger dose.
- Body study, 30 adults aged 45 and up, 28 days at 1000 mg twice a day: weight down 1.9 kg, lower blood pressure number down 7.01 mmHg, total cholesterol down 26.89 mg/dL, bad cholesterol down 18.73 mg/dL.
- Same study, the part usually left out: no change in muscle strength, how fast muscles tired, fitness or stair-climbing power. No change in how well insulin worked, liver fat or belly fat in either group.
- Safety across all three studies was good. Nothing turned up that would stop further testing at these doses and lengths.
- The longest anyone took it in the published studies is 28 days.
What this does not tell you: Every study is small. The biggest has 42 people and the longest ran 28 days, so nothing here covers long-term use. The body study found changes in four of eight things it measured, in 30 people. That is a clue for a future study, not proof. The maker helped pay for two of the three studies and employs authors on two of the three. Most important, the things a person would notice were measured and did not move. That means strength, fitness, how well insulin works, kidney function and inflammation. And that was in studies designed by the people with the most reason to hope they would.
The state of the research
MIB-626 deserves credit for something rare in this field. It went through the drug approval path with real studies against a dummy pill. They were registered, published in real journals, and reported the failures next to the wins. That is a higher bar than almost any consumer NAD product has cleared.
What that care bought is a clear answer on the blood marker, and no answer at all on health. The product raises blood NAD a lot, every time, and more with a bigger dose. Then look at the study with the cleanest health readout. Hospital patients with sudden kidney injury get kidney blood tests every day anyway. There, NAD went up almost threefold, and every marker of the illness stayed the same. The authors think the NAD rise was too slow, and they suggest testing it as a drip. That is a fair idea. It is also the second excuse offered for the second failed result in the same program.
The body study is the one that gets passed around. Read it carefully. Weight, blood pressure and blood fats moved. Strength, how fast muscles tired, fitness, stair-climbing power, how well insulin worked, liver fat and belly fat did not. A 28-day study in 30 people that reports a few wins among many measures, paid for in part by the maker, is a reason to run a bigger study. It is not a reason to conclude anything.
In this field, the maker paying for the study, and the maker employing the authors, is normal, not a rare footnote. It is spelled out on each page here rather than buried. Elysium Health paid for the NRPT studies, and company staff and shareholders were among the authors. The MIB-626 studies list Metro International Biotech as a funder, with company staff among the authors. ChromaDex paid for the nicotinamide riboside dose study, and two company staff were authors. Nestle Research staff wrote most of the study comparing three NAD boosters. None of that makes a result wrong. It does mean the studies paid for by someone else deserve more weight than their size alone suggests. And those independent studies are mostly the ones that found nothing.
The evidence, in charts
Fig. 1a · how many people
107people, across 2 studies in people cited here
| Study | People | Share |
|---|---|---|
| Nature Metabolism 2026 | 65 | 61% |
| FASEB BioAdvances 2025 | 42 | 39% |
One study holds 61% of these people, so the total rests more on one study than its size suggests. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 2 more studies in people give no headcount and are not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
All 4 sources here are studies in people.
- Study in people · done in people4100%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 3 different years, 2023 to 2026, counted from the list of sources on this page.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 4 · how much does what
Nobody has tested different amounts in people
This chart would show how the effect changes as the amount goes up. For this compound, nobody has measured that in people. So we leave it empty. We will not borrow an animal chart and pretend it works the same in people.
Fig. 5 · what the molecule is
- Kind of compound
- Supplement
- Molecule weight
- 334.2 Da. It is beta-nicotinamide mononucleotide; the proprietary part is the crystal form, not the molecule.
- Half-life
- Stated in words, not a numbersee the exact wording below
- Chain length
- None on file
Half-life as stated on file: The pharmacokinetic trial measured blood NMN and NAD exposure rather than a clean elimination half-life. NMN itself clears quickly and very little unmodified NMN was recovered in urine, while the downstream NAD rise built gradually over days and peaked late in the dosing period.
No amino acid sequence is on file for MIB-626, which is expected: a supplement is not built from amino acids.
The studies we cite
- Study in people2023MIB-626, an Oral Formulation of a Microcrystalline Unique Polymorph of β-Nicotinamide Mononucleotide, Increases Circulating Nicotinamide Adenine Dinucleotide and its Metabolome in Middle-Aged and Older Adults
This trial shows the tablet raises NAD in the blood, and nothing beyond that. 32 overweight or obese adults aged 55 to 80 took MIB-626 once a day, twice a day, or a dummy tablet for two weeks, and nobody involved knew which. NMN in the blood was clearly higher by the end, and NAD rose more on the bigger dose. Sex, weight and age made no difference. What was measured here was blood chemistry and safety, not how anyone felt or functioned.
Randomised, double-blind, placebo-controlled pharmacokinetic trial. 32 overweight or obese adults aged 55 to 80, block randomised and stratified by sex, given MIB-626 1000 mg once daily, twice daily, or placebo for 14 days. Blood NMN on day 14 was significantly higher than placebo, with mean AUClast 1.7-fold and 3.7-fold above baseline for the once and twice daily schedules, and there were substantial dose-related increases in blood NAD. Changes were unrelated to sex, BMI or age. Very little unmodified NMN was excreted in urine. The endpoints are blood metabolites and safety.
- Study in people2023Nicotinamide Adenine Dinucleotide Augmentation in Overweight or Obese Middle-Aged and Older Adults: A Physiologic Study
The tablet moved some body measurements and left every measure of physical function untouched. 30 overweight or obese adults aged 45 and over took MIB-626 or a dummy tablet for four weeks. Weight fell by about two kilograms. Blood pressure and cholesterol both came down. Strength, stamina, how quickly muscles tired and stair climbing power did not change. Insulin sensitivity, liver fat and belly fat did not change either. The manufacturer helped fund it. This study looked at many things at once, so treat any single result as a hint.
Randomised 2:1, 30 overweight or obese adults aged 45 and over, MIB-626 two 500 mg tablets twice daily for 28 days. Body weight fell 1.9 kg (95 percent CI -3.3 to -0.5, P=.008), diastolic blood pressure fell 7.01 mmHg (-13.44 to -0.59, P=.034), total cholesterol fell 26.89 mg/dL (P=.004) and LDL fell 18.73 mg/dL (P=.007). Muscle strength, muscle fatigability, aerobic capacity and stair-climbing power did not change. Insulin sensitivity, hepatic fat and intra-abdominal fat did not change in either group. Metro International Biotech, the manufacturer, is a listed funder. This is a physiologic study with multiple outcomes rather than a trial powered on one of them.
- Study in people2025Oral MIB-626 (β Nicotinamide Mononucleotide) Safely Raises Blood Nicotinamide Adenine Dinucleotide Levels in Hospitalized Patients With COVID-19 and Acute Kidney Injury: A Randomized Controlled Trial
The tablet raised NAD in very sick patients and made no difference to them. 42 adults in hospital with COVID-19 and sudden kidney injury took MIB-626 or dummy tablets twice a day for two weeks. NAD in the blood roughly doubled by the end. Kidney blood tests came out the same in both groups. So did inflammation markers and how ill people were. The authors want the drug tried as a drip instead. Two authors work for the manufacturer and a third consults for it.
NCT05038488. 42 adults hospitalised with COVID-19 and acute kidney injury randomised 3:2 to MIB-626 1.0 g or placebo tablets twice daily for 14 days. Blood NAD rose gradually from 16.0 to 25.5 to 42.6 micrograms per millilitre at baseline, day 5 and day 14, and NAD metabolites rose rapidly by day 3. Serum creatinine, cystatin C and serum markers of acute kidney injury did not differ between groups. Serum CRP, IL-6 and TNF alpha and indices of disease severity also did not differ. The authors attribute the absence of clinical effect to the slow rise in NAD and call for studies of parenteral administration. Two authors are employees of Metro International Biotech and a third is a consultant to the company.
- Study in people2026The differential impact of three different NAD(+) boosters on circulatory NAD and microbial metabolism in humans
This trial suggests oral NMN may work through gut bacteria rather than directly, which would apply to this product too. 65 healthy adults took one of three NAD boosters for two weeks, and everyone knew what they were taking. NMN and nicotinamide riboside both raised NAD in the blood. Plain nicotinamide did not keep it up. In lab tests with human gut bacteria, both turned into nicotinic acid, and nicotinic acid was the only one that raised NAD in blood directly. This needs confirming. Ten authors work for Nestle Research.
Randomised, open-label, placebo-controlled, 65 healthy adults, 14 days. NR and NMN comparably increased circulatory NAD while plain nicotinamide did not do so chronically. Using ex vivo fermentation with human microbiota, the authors found that NR and NMN give rise to nicotinic acid, and that in whole blood ex vivo nicotinic acid is a potent NAD booster while NMN, NR and nicotinamide are not, proposing a gut-dependent mechanism through the Preiss-Handler pathway. If confirmed, this applies to any oral NMN product including this one. Ten authors are Nestle Research employees.
Common questions
Has MIB-626 been tested in people?
Yes. 107 people given it across 4 completed trials cited here, 2 of which found nothing. MIB-626 is the only NMN product with a real set of studies in people: three studies with a dummy pill group, about 104 people in all.
What is the MIB-626 dosage?
No human dose established. Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose. 4 completed trials, 107 people given it
Is MIB-626 FDA-approved?
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.
Is MIB-626 different from the NMN I can buy?
The molecule is exactly the same: NMN. The difference is one defined crystal form, made to drug-factory standards and taken through the drug approval path. That is what makes steady dosing and drug filings possible. Nobody has tested head to head in people whether this crystal form gets into the body differently from a good-quality supplement.
What did the MIB-626 trials actually show?
That it raises blood NAD a lot, and more on a bigger dose. And that people handle 1000 mg twice a day well for up to 28 days. On things a person would notice, one study found weight, the lower blood pressure number and cholesterol lower over 28 days. The same study found no change in strength, fitness, how well insulin works or liver fat. A third study in hospital patients found no change in any marker of kidney damage, inflammation or how sick they were, even though blood NAD nearly tripled.
Can I buy MIB-626?
No. It is a drug still being tested, and it is not approved or sold anywhere. Products advertised as MIB-626 are not the product from the studies.
Does the FDA decision on NMN apply to MIB-626?
It runs the other way. MIB-626 being in the drug approval path is what led the FDA in 2022 to rule that NMN could not be sold as a supplement. That ruling rested on a rule that stops a drug under study from being sold as a supplement. The FDA reversed it in September 2025, because NMN had been sold as a supplement before the drug work began. None of that fight was about whether NMN works or is safe. A legal reversal is not a finding on safety or benefit.
Is it worth taking NMN at all based on this programme?
The studies show that NMN by mouth raises blood NAD in people. That was never really in doubt. They have not shown that raising blood NAD changes anything measurable about how a person functions. In the one study with hard health markers, it did not.