NMN Human Clinical Trials: What the Studies Show
NMN Human Clinical Trials
The published human NMN trials, described by study design only: who took part, how many people, what daily dose and for how long. We deliberately do not summarise outcomes — NMN has no authorised UK health claim, and small, short trials cannot tell you what NMN will do for you.
Small trials, described by design.
Human trials of NMN (nicotinamide mononucleotide) exist, but they are small (tens of participants, up to 108) and short (a single dose up to 12 weeks). The efficacy trials used 250–900mg a day; one safety study used 1250mg a day for four weeks. This page tells you how each study was built, not what it found.
NMN is widely sold in the UK but its position is not settled: a GB novel food application for β-NMN (FSA reference RP-2116) is under assessment by the Food Standards Agency, and EFSA published a positive safety opinion in the EU in 2026 with formal authorisation still pending. No authorised UK or EU health claim exists for NMN, so we describe the research by design only — population, size, dose and duration — and make no claim about effects.
The human trials, in context.
Interest in NMN comes from its role as a precursor in the body's production of NAD+, a coenzyme found in every cell. Most early NMN research was done in cells and animals. The human evidence base is younger and much smaller: mostly randomised, placebo-controlled studies with participant numbers in the tens, running for weeks, not years.
Because the trials differ in population, dose, duration and what they measured, they are not directly comparable — and because none of them supports an authorised health claim, we do not report their results. If you want to read the outcomes, every paper is on our research references page.
For how these study doses relate to products, see NMN 500mg vs 1000mg and the side-by-side compare NMN table. For timing questions, when to take NMN covers the one trial that compared morning and evening intake.
Key NMN trials, by design.
Population, size, daily dose and duration as stated in each published paper. This is not a complete list of all NMN research, and it deliberately has no results column.
| Study | Population | n | Daily dose | Duration | Design |
|---|---|---|---|---|---|
| Yoshino et al., Science 2021 | Postmenopausal women with prediabetes | 25 | 250mg | 10 weeks | Randomised, placebo-controlled |
| Igarashi et al., npj Aging 2022 | Healthy older men | 42 | 250mg | 12 weeks | Randomised, placebo-controlled |
| Kim et al., Nutrients 2022 | Adults aged 65+ | 108 | 250mg | 12 weeks | Morning vs evening intake arms |
| Yi et al., GeroScience 2023 | Healthy middle-aged adults | 80 | 300 / 600 / 900mg | 60 days | Randomised, placebo-controlled, dose-ranging |
| Fukamizu et al., Sci Rep 2022 | Healthy adults | 31 | 1250mg | 4 weeks | Safety study |
| Liao et al., J Int Soc Sports Nutr 2021 | Recreationally trained runners aged 27–50 | 48 | 300 / 600 / 1200mg | 6 weeks | Randomised, placebo-controlled, alongside exercise training |
| Irie et al., Endocrine Journal 2020 | Healthy men | 10 | 100 / 250 / 500mg | Single dose | Non-randomised, single-dose safety and metabolism study |
Study designs, populations and measurement methods differ, so the trials should not be read as directly comparable. The efficacy trials above used 250–900mg/day, except Liao 2021, which included a 1200mg arm. Full citations: research references.
What the trials measured.
It helps to separate the types of measurement the trials used, because they are different kinds of evidence. A laboratory marker is not the same as a health outcome, and none of these supports an authorised claim.
Blood NAD+ and related metabolites. The most common measurement: blood samples before and after supplementation. It is a laboratory readout of what is in the blood, not a measure of how anyone feels or functions. Background: what is NAD+.
Physical tests. Some trials added walking tests, grip strength or exercise-capacity measures, recorded in a small group over a short window.
Metabolic markers. A few trials looked at blood chemistry such as insulin-related markers, as exploratory measures in small groups.
Safety panels. Trials monitored standard blood tests, vital signs and reported side effects at the dose used.
We list what was measured, not what was found. That is the honest scope for an ingredient with no authorised health claim.
Safety in the trials, by design.
Every trial listed monitored safety, and one was built specifically for it: Fukamizu et al. (Scientific Reports, 2022) gave 31 healthy adults 1250mg of NMN a day for four weeks. Irie et al. (2020) looked at single doses of 100, 250 and 500mg in 10 healthy men. All of these windows are short. Long-term human safety data for NMN does not exist.
For the side-effect question in full, read NMN side effects. Trial data does not replace advice from a healthcare professional about your own situation.
Research only applies if a product actually contains what its label says. See how to check for genuine NMN — test method, batch numbers and an accredited laboratory.
From study doses to labels.
We make and sell NMN. Every batch is tested by an ISO/IEC 17025-accredited laboratory and UK manufactured. Compare our formulas' NMN dose against the trial range.
NMN trials FAQ.
Last reviewed 5 October 2026 by the Vitality Supplements Editorial Team, written to our editorial standards. We make and sell NMN products, which is why this page describes the research by design only and does not summarise outcomes. Each trial's population, size, dose and duration was checked against the published paper. First published 28 July 2026; rebuilt 5 October 2026 with corrected trial details, an unverifiable trial entry removed, and the UK regulatory status added.
Food supplements should not be used as a substitute for a varied, balanced diet and a healthy lifestyle. Do not exceed the stated recommended daily dose. NMN is not yet an authorised novel food in Great Britain (application RP-2116 under assessment). No authorised UK or EU health claims exist for NMN, and no medicinal, disease or anti-ageing claims are made. Not suitable for children. Consult a healthcare professional before use if pregnant, breastfeeding, taking medication or under medical supervision. General information, not medical advice. See our disclaimer · Contact