A reference work, not a recommendation to use: this profile describes mechanism and evidence and does not replace medical advice. The claims come from marketing and forums and are tested here, not endorsed.

Claims checked

  • Slows aging and extends healthy lifespan

    Not studied

    Longevity · healthy · Animal study

    In humans, there is no study with aging or lifespan endpoints. Only the rise of NAD+ in blood is documented [5][6]. The effects on signs of aging come from mice [1]; an algorithmically calculated “biological age” in an RCT close to the manufacturer is not a validated aging endpoint [5].[6]

  • Better insulin sensitivity and blood glucose values

    Mixed results

    Energy & metabolism · healthy (partly overweight or prediabetes) · Human, randomised

    One RCT with a clamp test found better insulin sensitivity in muscle in prediabetes [7]; two meta-analyses found no effect on fasting glucose, HbA1c or HOMA-IR [8][9].[8][9]

  • More muscle strength and physical performance

    No benefit

    Muscle & performance · healthy (mainly over 60 years, partly with diabetes or overweight) · Human, randomised

    Meta-analysis of RCTs: no effect on muscle mass, grip strength, gait speed or sit-to-stand test [10]. Positive individual findings (walking test, ventilatory thresholds in runners) are unconfirmed and partly close to the manufacturer [5][11].[5][11]

  • Lowers blood pressure

    Mixed results

    Heart & blood vessels · mixed: healthy people and people with metabolic risk · Human, randomised

    In one meta-analysis, diastolic blood pressure fell slightly, systolic did not [9].

Mechanism of action

Evidence map: Nicotinamide mononucleotide (NMN)

Each line stands for a published finding; line style and color show where it comes from. The filter hides weaker evidence levels. Sources: see references.

Nicotinamide mononucleotide (NMN) is converted in the cell to NAD+ by NMN adenylyltransferases (NMNAT); NAD+ is the cofactor of numerous redox reactions and a substrate of sirtuins and PARP enzymes. In mice, NAD+ availability falls with age; NMN given orally over twelve months was rapidly processed to NAD+ and dampened weight gain as well as age-related deterioration of energy metabolism, physical activity and insulin sensitivity in normally aging mice [1]. How NMN gets into cells is disputed: one research group described Slc12a8 as a sodium-dependent NMN transporter in the mouse small intestine [2], while others saw insufficient evidence for this [3]. Isotope-labeled flux analyses in mice showed that intravenously administered NMN or nicotinamide riboside reaches several tissues intact, whereas orally administered NMN is largely broken down to nicotinamide in the liver [4].

In humans, oral NMN raises the NAD+ level in blood. In a multicenter RCT with 80 healthy middle-aged adults, NAD+ rose in all NMN groups compared with placebo; the distance walked in the six-minute test increased more, HOMA-IR did not change, and several authors were employed by manufacturing companies [5]. In healthy older men, NAD+ in whole blood also rose; gait speed and grip strength improved only nominally, body composition not at all [6]. In overweight postmenopausal women with prediabetes, NMN increased insulin-stimulated glucose uptake in the clamp test and insulin signaling in muscle in a ten-week RCT [7]. A meta-analysis of eight RCTs with 342 mostly non-diabetic adults, by contrast, found no effect on fasting glucose, insulin, HbA1c, HOMA-IR or blood lipids [8]. A meta-analysis of 15 RCTs confirmed short-term tolerability but found no broad metabolic effects, only a slightly lowered diastolic blood pressure [9]. For muscle mass, grip strength and gait speed in people over 60, a meta-analysis showed no benefit [10]. In 48 recreational runners in training, oxygen uptake and power at the ventilatory thresholds rose in two of three NMN groups, but maximal oxygen uptake did not [11].

Theoretical risks are also discussed: in cell and mouse models, the NAD+-producing enzyme NAMPT promoted the inflammatory secretory phenotype of senescent cells (SASP), which is why the authors advise targeted use of NAD+ precursors [12]. With nicotinamide riboside, cancer incidence and brain metastases rose in a mouse model of triple-negative breast cancer [13]; there are no data on this for NMN or for humans. In 2026, EFSA assessed β-NMN as a novel food as safe for adults and describes the changing classification by the US agency FDA [14]. Analyses of over-the-counter NMN and urolithin A products found deviations from the declared active ingredient content between +28.6% and −100% [15].

Synaptik serves solely to explain biochemistry and pharmacology and is not medical advice or a recommendation to take anything.

Mechanism of action only. Schematic longitudinal section through the edge of a skeletal muscle fibre with a capillary, not to scale. The figure alternates between rest with insulin and a short bout of exercise. Particles, speeds and the bars of the live readout are model outputs (illustrative) and only show the direction reported by the studies; the numbers in the readout and the text come from the studies cited.
Compound
View

insulin  glucose  H⁺  phosphocreatine  bicarbonate  compound  glow = active signalling node

In 25 postmenopausal women with overweight and prediabetes, ten weeks of NMN in a placebo-controlled study increased insulin-stimulated glucose uptake in the clamp and insulin signalling (AKT, mTOR) in muscle [21]. A meta-analysis of eight RCTs with 342 mostly non-diabetic adults, by contrast, found no effect on fasting glucose, insulin, HbA1c or HOMA-IR [22]. In the model the signal is amplified from Akt onwards; GLUT4 was not measured, and the size of the effect is not to scale.

Tap or focus a labelled part for a short explanation.

Also acting here, not drawn

Assigned to the site of action Enterocyte brush border (microvilli with enzymes and transporters); not drawn in its figure: the proposed transporter Slc12a8 is disputed.

Targets

TargetTypeActionKey dataEvidence
NMN adenylyltransferases (NMNAT)EnzymeBinding Animal study[1][4]
Slc12a8 (proposed NMN transporter)TransporterBinding Animal study[2][3]
Insulin signaling pathway in muscle (AKT, mTOR)Signaling pathwayActivator Human, randomised[7]

Effect profile

Which signaling systems the compound affects according to current data. ↑ enhanced, ↓ dampened, ≈ modulated, ○ no effect; dots = evidence level.

  • Dopamineno data
  • Noradrenalineno data
  • Serotoninno data
  • Acetylcholineno data
  • Glutamate · AMPAno data
  • Glutamate · NMDAno data
  • GABAno data
  • Histamineno data
  • Orexinno data
  • Adenosineno data
  • Opioidsno data
  • Melatoninno data
  • Neurotrophinsno data
  • Blood flowno data
  • Nitric oxideno data
  • Energy metabolism↑ · NAD+ and NAD+ metabolites in blood rise in several RCTs; whether this is functionally relevant remains open[5][6]
  • Insulin · glucoseunclear · better insulin sensitivity in muscle in prediabetes in one RCT; meta-analyses without effect on glucose, HbA1c and HOMA-IR[7][8][9]
  • Inflammation · oxidativeunclear · NAD+ production via NAMPT promoted the inflammatory secretory phenotype of senescent cells in cell and mouse models[12]
  • Stress axisno data
  • Testosterone axisno data
  • Endocannabinoidsno data
  • Autophagy · senescenceno data
  • Immune systemno data
  • Lipid metabolismno data
  • Coagulation · fibrinolysisno data
  • Methylationno data

Routes of administration and bioavailability

How much of a compound reaches the blood or target tissue depends on the route into the body and on the dosage form. All routes of administration explained

  • Oral (swallowed) · β-NMN (capsules, powder)

    absolute bioavailability not determined; NAD+ in blood rises (human)

    In RCTs, NAD+ and its metabolites rise in blood [5][6]. In mice, orally administered NMN is largely broken down to nicotinamide in the liver [4]. EFSA regards β-NMN as a bioavailable source of nicotinamide [14].[5][6]

    Human, randomised

  • Intravenous · Infusion (animal experiment)

    In mice, intravenously administered NMN reached several tissues intact [4]. Controlled human studies on intravenous administration were not found.

    Animal study

  • Sublingual (under the tongue) · Lozenges, powder

    Marketed as better absorbable; a controlled study of bioavailability in humans was not found in PubMed (as of October 23, 2026).

    No data

Human studies

  • Dose comparison in healthy middle-aged adults

    RCT, multicenter, double-blind, placebo-controlled, close to the manufacturer · healthy · n = 80 · 60 days

    Measured: Blood NAD+; six-minute walk test, HOMA-IR, SF-36, “biological age”

    Result: NAD+ increased in all NMN groups; walking distance and SF-36 better; HOMA-IR unchanged.[5]

    Human, randomised

  • Healthy older men

    RCT, double-blind, placebo-controlled · healthy (older men) · 6 or 12 weeks

    Measured: NAD+ metabolome in whole blood, muscle function, body composition

    Result: NAD+ increased; gait speed and grip strength better only nominally; body composition unchanged.[6]

    Human, randomised

  • Women with prediabetes

    RCT, double-blind, placebo-controlled · overweight, prediabetes, after menopause · n = 25 · 10 weeks

    Measured: insulin-stimulated glucose uptake (clamp), insulin signaling in muscle

    Result: Insulin sensitivity and AKT/mTOR signal in muscle increased, not with placebo.[7]

    Human, randomised

  • Recreational runners in training

    RCT, double-blind, placebo-controlled, four groups · healthy (trained) · n = 48 · 6 weeks

    Measured: cardiopulmonary exercise testing

    Result: Oxygen uptake and power at the ventilatory thresholds increased; VO2max unchanged.[11]

    Human, randomised

  • Meta-analysis glucose and lipid metabolism

    systematic review and meta-analysis of 8 RCTs · middle-aged and older adults, mostly without diabetes · n = 342 · 14 days to 12 weeks

    Measured: Fasting glucose, insulin, HbA1c, HOMA-IR, blood lipids

    Result: no significant effect.[8]

    Human, randomised

  • Meta-analysis muscle mass and function

    systematic review and meta-analysis of RCTs (NMN and NR) · adults, mean age 60.9 to 83 years · 3 to 24 weeks

    Measured: Skeletal muscle index, grip strength, gait speed, sit-to-stand test

    Result: NMN without significant effect on all endpoints.[10]

    Human, randomised

Risks and warnings

  • Lack of long-term data

    In a meta-analysis of RCTs lasting 14 days to 24 weeks, NMN was not associated with more adverse events or with elevated liver values [9]. Data over several years are lacking.

    Human, randomised

  • Theoretical: cancer and cellular aging

    Concern derived from cell and animal data and not studied in humans: NAD+ production promoted the inflammatory secretory phenotype of senescent cells [12]; nicotinamide riboside increased breast cancer metastases in a mouse model [13].

    Animal study

  • Findings in animal experiments

    In a 90-day study in rats, high doses showed effects on reproductive organs; EFSA considered the margin of safety sufficient but excluded pregnant and lactating women [14].

    Animal study

  • Product quality

    Measured active ingredient contents of over-the-counter NMN and urolithin A products deviated from the declaration by +28.6% to −100% [15].

    Laboratory

  • Conflicts of interest

    In several human studies, authors were employed by NMN manufacturers [5][6] or involved in patents and license revenue [7].

    No data

Fact check: common claims

  • not supported

    “NMN makes you biologically younger”

    The only human finding: in an RCT close to the manufacturer, a “biological age” calculated from blood values stayed stable with NMN and rose with placebo [5]; this is not a validated aging endpoint. The remaining evidence comes from mice [1].

  • supported

    “NMN raises the NAD+ level”

    Shown for blood in several RCTs [5][6]; whether NAD+ also rises meaningfully in muscle or brain has hardly been studied in humans.

  • partly supported

    “NMN improves insulin sensitivity”

    Positive in one clamp study in women with prediabetes [7]; meta-analyses found no effects on glucose, HbA1c and HOMA-IR [8][9].

  • not supported

    “NMN is taken up intact into cells via a dedicated transporter”

    Slc12a8 was proposed as a transporter in mice [2], a finding that is disputed [3]; orally administered NMN is largely broken down to nicotinamide in mice [4].

  • not supported

    “NMN strengthens muscles in old age”

    A meta-analysis of RCTs found no effect on muscle mass, grip strength or gait speed [10].

Pharmacokinetics

Absorption
Oral; NAD+ in blood rises in RCTs [5][6]. In mice, oral NMN is largely broken down to nicotinamide in the liver, while intravenous NMN is distributed intact [4].
Half-life
Not verified.
Metabolism
Conversion to NAD+ by NMNAT; degradation to nicotinamide [4]; EFSA regards NMN as a bioavailable nicotinamide source [14].
Entry into the brain
Not studied in humans.

Legal status

Germany
Novel food: in 2026, EFSA assessed synthetic β-NMN as safe for adults under the proposed conditions of use, pregnant and lactating women excluded [14]. The Union list of novel foods (consolidated version, as of August 10, 2026) contains no entry for NMN [16].
EU
EFSA opinion 2026 positive [14]; no entry for nicotinamide mononucleotide (NMN) in the consolidated Union list of novel foods, as of August 10, 2026 (German and English versions searched, 0 hits) [16]; no EU legal act with “nicotinamide mononucleotide” in the English title found via Cellar (October 24, 2026).
USA
In 2022, the FDA classified β-NMN as excluded from the definition of dietary supplements because it had previously been investigated as a drug, and revised this position in 2025 (according to the EFSA opinion) [14].
Other countries
Canada: regulated as a natural health product; according to the applicant, on the market as a dietary supplement since 2019 or 2020 in, among others, Australia, Hong Kong, South Korea, Japan, New Zealand and Taiwan [14].

Related compounds

Nicotinamide riboside (NR)same classNicotinamid (Niacinamid)same class (German only)

Open questions

  • Does NAD+ also rise in human muscle, liver or brain after oral administration, or mainly in blood?
  • Do people with a low NAD+ baseline or metabolic disorders benefit more than healthy people?
  • Can the insulin finding in prediabetes be confirmed in larger, independent studies?
  • Are the theoretical concerns about cancer and senescence relevant to long-term use in humans?

References

  1. Mills KF, Yoshida S, Stein LR, Grozio A, Kubota S, Sasaki Y, et al. Long-term administration of nicotinamide mononucleotide mitigates age-associated physiological decline in mice. Cell Metab. 2016;24(6):795–806. doi:10.1016/j.cmet.2016.09.013 · PubMed
  2. Grozio A, Mills KF, Yoshino J, Bruzzone S, Sociali G, Tokizane K, et al. Slc12a8 is a nicotinamide mononucleotide transporter. Nat Metab. 2019;1(1):47–57. doi:10.1038/s42255-018-0009-4 · PubMed
  3. Schmidt MS, Brenner C. Absence of evidence that Slc12a8 encodes a nicotinamide mononucleotide transporter. Nat Metab. 2019;1(7):660–1. doi:10.1038/s42255-019-0085-0 · PubMed
  4. Liu L, Su X, Quinn WJ, Hui S, Krukenberg K, Frederick DW, et al. Quantitative analysis of NAD synthesis-breakdown fluxes. Cell Metab. 2018;27(5):1067–80.e5. doi:10.1016/j.cmet.2018.03.018 · PubMed
  5. Yi L, Maier AB, Tao R, Lin Z, Vaidya A, Pendse S, et al. The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults: a randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose-dependent clinical trial. Geroscience. 2023;45(1):29–43. doi:10.1007/s11357-022-00705-1 · PubMed
  6. Igarashi M, Nakagawa-Nagahama Y, Miura M, Kashiwabara K, Yaku K, Sawada M, et al. Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men. NPJ Aging. 2022;8(1):5. doi:10.1038/s41514-022-00084-z · PubMed
  7. Yoshino M, Yoshino J, Kayser BD, Patti GJ, Franczyk MP, Mills KF, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021;372(6547):1224–9. doi:10.1126/science.abe9985 · PubMed
  8. Chen F, Zhou D, Kong AP, Yim NT, Dai S, Chen YN, et al. Effects of nicotinamide mononucleotide on glucose and lipid metabolism in adults: a systematic review and meta-analysis of randomised controlled trials. Curr Diab Rep. 2024;25(1):4. doi:10.1007/s11892-024-01557-z · PubMed
  9. Yang W, Huang J, Tang Z, Chen C, Sun Y. Safety and metabolism-related outcomes of oral nicotinamide mononucleotide supplementation in adults: a systematic review and meta-analysis. Nutrients. 2026;18(14):2251. doi:10.3390/nu18142251 · PubMed
  10. Prokopidis K, Moriarty F, Bahat G, McLean J, Church DD, Patel HP. The effect of nicotinamide mononucleotide and riboside on skeletal muscle mass and function: a systematic review and meta-analysis. J Cachexia Sarcopenia Muscle. 2025;16(3):e13799. doi:10.1002/jcsm.13799 · PubMed
  11. Liao B, Zhao Y, Wang D, Zhang X, Hao X, Hu M. Nicotinamide mononucleotide supplementation enhances aerobic capacity in amateur runners: a randomized, double-blind study. J Int Soc Sports Nutr. 2021;18(1):54. doi:10.1186/s12970-021-00442-4 · PubMed
  12. Nacarelli T, Lau L, Fukumoto T, Zundell J, Fatkhutdinov N, Wu S, et al. NAD+ metabolism governs the proinflammatory senescence-associated secretome. Nat Cell Biol. 2019;21(3):397–407. doi:10.1038/s41556-019-0287-4 · PubMed
  13. Maric T, Bazhin A, Khodakivskyi P, Mikhaylov G, Solodnikova E, Yevtodiyenko A, et al. A bioluminescent-based probe for in vivo non-invasive monitoring of nicotinamide riboside uptake reveals a link between metastasis and NAD+ metabolism. Biosens Bioelectron. 2023;220:114826. doi:10.1016/j.bios.2022.114826 · PubMed
  14. EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA); Turck D, Bohn T, Cámara M, Castenmiller J, De Henauw S, Jos Á, et al. Safety of beta-nicotinamide mononucleotide (β-NMN) pursuant the regulation (EU) 2015/2283 and the bioavailability of nicotinamide from this source in the context of Directive 2002/46/EC. EFSA J. 2026;24(5):e10007. doi:10.2903/j.efsa.2026.10007 · PubMed
  15. Sandalova E, Li H, Guan L, Raj SD, Lim TG, Tian E, et al. Testing the amount of nicotinamide mononucleotide and urolithin A as compared to the label claim. Geroscience. 2024;46(5):5075–83. doi:10.1007/s11357-024-01257-2 · PubMed
  16. Durchführungsverordnung (EU) 2017/2470 der Kommission vom 20. Dezember 2017 zur Erstellung der Unionsliste der neuartigen Lebensmittel gemäß der Verordnung (EU) 2015/2283 des Europäischen Parlaments und des Rates über neuartige Lebensmittel. ABl. L 351 vom 30.12.2017, S. 72. Konsolidierte Fassung vom 10.08.2026 (CELEX 02017R2470-20260810).
How this profile was checked

Last reviewed: 2026-10-24. All sources with a DOI or PMID were resolved automatically via Crossref or doi.org and PubMed.

Translated from the German profile (version of 2026-10-24); translation checked on 2026-10-26.

Checked

  • All references retrieved via PubMed; DOIs and PMIDs taken from the PubMed records.
  • Checked against the abstract: 12 months of NMN in mice, no toxicity [1]; Slc12a8 sodium-dependent, NMN-specific (mouse) [2]; oral degradation to nicotinamide in the liver, intravenous intact [4]; 80 healthy participants, NAD+ ↑, walk test ↑, HOMA-IR unchanged, “biological age”, employees of Abinopharm and Aba Chemicals among the authors [5]; nominal improvement of gait and grip strength, employees of Mitsubishi Corporation Life Sciences [6]; clamp, AKT/mTOR, patent licenses of a co-author [7]; 8 RCTs, 342 participants, no effect [8]; 15 RCTs, diastolic blood pressure slightly ↓, 14 days to 24 weeks [9]; no effect on SMI, grip strength, gait speed [10]; 48 runners, VO2max unchanged [11]; NAMPT and SASP [12]; NR and TNBC metastases (mouse) [13]; +28.6% to −100% [15].
  • Checked in the full text: FDA exclusion in 2022 and revision in 2025, distribution in other countries, rat finding and exclusion of pregnant and lactating women [14]; case numbers 13 vs. 12 of the study [7] from the study table of the meta-analysis [10]; study populations of the meta-analysis [10] (also type 2 diabetes, prediabetes, overweight).
  • ClinicalTrials.gov: 51 entries for “nicotinamide mononucleotide” (October 23, 2026).
  • Union list searched in the consolidated text CELEX 02017R2470-20260810 (Cellar, XHTML, October 24, 2026): no hit for NMN, “Nukleotid”/“Nucleotid” or “Mononu…”; the nicotinamide entries concern only nicotinamide riboside chloride and 1-methylnicotinamide chloride [16].
  • Related entries on October 24, 2026 according to K1/G1: reverse link to nicotinamide added, “same class” on both sides (across the family boundary nad-vorstufen/vitamin-b3-formen; the exception “other form” is named in the guideline only for nicotinamide ↔ nicotinamide-ribosid); a conversion of nicotinamide to NMN in vivo in humans is not documented in the profiles. nicotinamid-ribosid remains “same class” as with all members of families outside the nutrient families (K1 applies to vitamin and mineral families).
  • Legal status (October 24, 2026, package kat-p1): consolidated Union list 02017R2470-20260810 searched in German and English for “mononukl”, “mononucl” and “NMN”, 0 hits [16]; Cellar SPARQL over English legal act titles: no hit with “mononucleotide”.

Not verified

  • Whether, as of the consolidated Union list (August 10, 2026), an authorization act for β-NMN was adopted; the Cellar title search on October 24, 2026 found none, and the Official Journal was not reviewed individually.
  • The FDA positions of 2022 and 2025 are documented only via the EFSA opinion [14], not via FDA documents themselves.
  • Case number of the study [6] and half-life of NMN in humans not given in the abstract.
  • Controlled human studies on sublingual or intravenous NMN administration not found.

No dosages, no sources of supply. This information does not replace medical advice.

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