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The science of healthy ageing
Every longevity brand claims the science. Few show it. Here is the biology, nine human NMN trials and the peer-reviewed research our founder conducted as joint first author.
Our founder’s published research
Dr Elena Seranova
Joint first author · Cell Reports, 2023
Pictured with Dr Sovan Sarkar, scientific advisor to NMN Bio.
Our own published research01 / Start with the biology
Nicotinamide adenine dinucleotide, or NAD+, is a coenzyme found in living cells. It helps mitochondria turn food into usable energy and is consumed by enzymes involved in DNA repair and cellular maintenance, including PARPs and sirtuins.
NAD+ can decline with age as the balance between production and consumption changes. PARPs consume NAD+ in response to DNA damage. CD38 also consumes NAD+, and increased CD38 activity has been linked to age-related NAD+ decline and mitochondrial dysfunction in experimental models.
These enzymes draw on the same NAD+ pool that sirtuins use. The salvage pathway helps refill that pool, but production may not keep pace with consumption. The balance varies across tissues and conditions; it is not a uniform decline in every cell.
Explore the mechanism: Camacho-Pereira et al., Cell Metabolism, 2016 ↗Inside your cells
Helps transfer energy from the food you eat.
Used by PARPs as they respond to DNA damage.
Supports NAD-dependent enzymes called sirtuins.
02 / Meet the precursor
Nicotinamide mononucleotide, or NMN, is a direct precursor to NAD+. Inside cells, the enzyme NMNAT converts NMN into NAD+ in one enzymatic step.
Nicotinamide mononucleotide
A building block for NAD+.Catalyses the conversion
Nicotinamide adenine dinucleotide
Used in energy metabolism and cellular maintenance.NMN is not NAD+. Nicotinamide riboside (NR) is converted into NMN before NAD+. Nicotinamide, a form of vitamin B3, depends on the enzyme NAMPT to enter this salvage pathway. Oral processing and bioavailability involve additional steps: swallowing a precursor is not the same as delivering intact NAD+ to a cell. This illustration shows the intracellular conversion, not absorption or a proven health benefit. Read the pathway review ↗
03 / A fair comparison
Both are NAD+ precursors. The useful comparison is what has been measured in human trials and in the laboratory, alongside what those studies cannot tell us.
Nicotinamide mononucleotide
One enzymatic step from intracellular NMN to NAD+. The 2021 Yoshino trial measured muscle insulin sensitivity using a hyperinsulinaemic euglycaemic clamp. Yi and colleagues later tested daily doses of 300, 600 and 900 mg. See the human trial results.
Nicotinamide riboside
NR is converted to NMN before NAD+. Its human research history includes a 2016 oral-bioavailability study. It also restored NAD in our published neuronal model. The additional biochemical step does not establish that NR is less effective as an oral supplement.
In the 2023 Cell Reports study, nicotinamide also rescued cell viability. Blocking NAMPT with FK866 abolished nicotinamide’s protective effect, while the effects of NMN and NR remained. Both precursors act downstream of NAMPT in this pathway.
This is the mechanistic distinction we measured: different routes to replenishing NAD+. Our choice of NMN is informed by that research and the human metabolic studies. Neither a shorter pathway nor a cell-rescue experiment establishes clinical superiority over NR.
Read the experiments and methods ↗04 / The human evidence
What has NMN actually done in humans? The 9 trials below cover NAD levels, metabolic health, physical function, short-term tolerability and early disease research. Most are small and short. We include mixed results and identify missed primary endpoints, as well as promising findings.
Showing 9 of 9 selected studies
Swipe to explore the studies
| Study & source | Participants & protocol | Findings & limitations | Research focus |
|---|---|---|---|
| Yoshino et al.Science · 2021 PubMed ↗ |
25 postmenopausal women with prediabetes; randomised, double-blind, placebo-controlled250 mg / day 10 weeks |
Muscle insulin sensitivity improved, measured with a hyperinsulinaemic euglycaemic clamp.No change in body composition. A small, specific study population. | Metabolic health NCT03151239 ↗ |
| Yi et al.GeroScience · 2023 PubMed ↗ |
80 healthy middle-aged adults300, 600 or 900 mg / day 60 days |
Blood NAD increased, with the highest levels at 600 and 900 mg. Six-minute walking distance and SF-36 general-health scores improved versus placebo.No significant difference in HOMA-IR, a measure of insulin resistance. | NAD+ levels NCT04823260 ↗ |
| Morifuji et al.GeroScience · 2024 PubMed ↗ |
60 older adults250 mg / day 12 weeks |
Blood NAD+ increased. Four-metre walking time and Pittsburgh Sleep Quality Index scores improved versus placebo as secondary outcomes.Primary endpoint not met: no significant difference in the stepping test. | Physical function UMIN000047871 ↗ |
| Fukamizu et al.Scientific Reports · 2022 PubMed ↗ |
31 healthy adults1,250 mg / day 4 weeks |
No severe adverse events were observed; measured laboratory and clinical changes remained within normal physiological variation.Four weeks of tolerability data does not establish long-term safety. | Safety UMIN000043084 ↗ |
| Liao et al.JISSN · 2021 PubMed ↗ |
48 recreational runners300, 600 or 1,200 mg / day 6 weeks |
Some ventilatory threshold measures improved.No improvement in VO₂max. All groups also undertook exercise training. | Physical function ChiCTR2000035138 ↗ |
| Kim et al.Nutrients · 2022 PubMed ↗ |
108 older Japanese adults250 mg / day 12 weeks |
Afternoon NMN showed signals in lower limb function and drowsiness.Improvements also occurred in placebo groups; findings are mixed. | Physical function See study for registration |
| Katayoshi et al.Scientific Reports · 2023 PubMed ↗ |
Adults in a placebo-controlled trial250 mg / day 12 weeks |
NAD metabolism changed.No significant overall improvement in arterial stiffness. | Metabolic health See study for registration |
| Akasaka et al.Geriatrics & Gerontology Int. · 2023 PubMed ↗ |
Older adults with diabetes250 mg / day 24 weeks |
Physical function and safety were assessed.Small exploratory trial; no established improvement in grip strength or walking speed. | Physical function See study for registration |
| Li et al.Nature Medicine · 2026 PubMed ↗ |
25 patients with immune thrombocytopenia450 mg twice daily 2 weeks of treatment |
5 of 25 patients met the primary platelet-response endpoint.Open-label, single-arm disease trial. Not evidence of wellness benefits. | Disease research NCT06776510 ↗ |
Each study links to PubMed. Registration numbers are shown where checked.
Study doses describe research protocols, not personal dosing advice.
These are 9 selected human trials,
not an exhaustive count of published NMN research.
05 / Our contribution
Laboratory research · Human cell modelMost supplement companies cite science. We generated some. Our founder, Dr Elena Seranova, is joint first author of the 2023 Cell Reports paper shown here. The work was carried out in Dr Sovan Sarkar’s laboratory at the University of Birmingham, with collaborators at Newcastle, Glasgow, MIT and the Whitehead Institute.
The team built human neurons from embryonic stem cells with ATG5, a gene needed for autophagy, deleted. Autophagy is the cell’s recycling process and helps maintain proteostasis, the balance of proteins within cells. Without it, NAD consumption increased, NAD levels fell, mitochondria lost their membrane potential and cells died.
Supplying NMN restored NAD levels, rescued mitochondrial function and improved neuronal survival in this model. Elena was one of the researchers who designed and performed the majority of the experiments.
What this does not mean
This was laboratory research. It does not show that taking NMN prevents neurodegeneration, treats disease or
extends human life.
Two more founder-coauthored papers exploring autophagy and cellular function.
Developmental Cell · 2022
Kataura T, et al. Developmental Cell, 2022;57(22):2584 to 2598.
The companion finding runs in the opposite direction: autophagy helps maintain NAD levels in the first place. Read together, the papers describe a two-way relationship. Autophagy sustains NAD, while NAD depletion contributes to cell death when autophagy fails.
Explore the paper ↗Stem Cell Reports · 2026
Kocak G, et al. Stem Cell Reports, 2026;21(1):102744.
Human stem cell-derived tear gland organoids lacking autophagy developed and secreted improperly. NMN and melatonin improved secretory function; NMN also reduced protein aggregates and cell death. This is laboratory research relevant to dry eye disease, not evidence that a supplement treats it.
We include this paper because it is part of the same body of work, not as evidence for a product benefit.
Explore the paper ↗06 / The people behind the papers
The people behind our approach to NAD+, autophagy and cellular health.
Founder · NMN Bio
MSc Translational Neuroscience, University of Sheffield. PhD Stem Cell Biology and Autophagy, University of Birmingham. Joint first author of the 2023 Cell Reports paper and co-author in Developmental Cell and Stem Cell Reports. She founded NMN Bio after struggling to find an NMN supplier whose certificates of analysis she trusted.
View Google Scholar publications ↗
Scientific advisor
Principal investigator at the University of Birmingham and senior author of the Cell Reports study. His laboratory investigates autophagy in neurodegenerative and lysosomal storage disease using stem cell-derived models. During his doctoral research at the University of Cambridge, he discovered mTOR-independent pathways regulating autophagy.
View university profile and research ↗07 / Keep asking questions
Does NMN really work, is it good for you, and what are its limits? Start with the evidence and the questions it has yet to answer.
Several small trials found NMN well tolerated over their study periods. A four-week study at 1,250 mg daily reported no severe adverse events. That does not establish safety over years or for every person. Read the safety trial.
People may stop because they do not notice a benefit, because of cost, or because they have concerns about tolerability. A personal experience cannot establish whether a molecule works generally. Persistent symptoms or concerns about interactions belong in a conversation with a qualified clinician.
For a broader introduction to NMN, its evidence and practical questions, read our complete guide to NMN.
The human trials used the materials described in their own publications and are not clinical trials of the finished NMN Bio product. In the separate Cell Reports laboratory study, NMN Bio supplied the NMN and ChromaDex supplied the NR. That supplier link does not turn a cell experiment into evidence of a clinical benefit.
Our NMN is third-party tested for purity, heavy metals, microbiological contamination and pH, then encapsulated in the UK. Contact our support team with your batch number to request its Certificate of Analysis. Read our testing and supply-chain standards.
Request your batch COA ↗Understand the science. Make your choice.
Third-party tested. Encapsulated in the UK. Founded and formulated by a published NAD researcher.
