The Cellular Battery.
Restored, precisely.
NAD+ is the molecule every living cell needs to produce energy, repair itself, and slow its own ageing. It declines steeply after fifty. NMN supplementation is the most-studied way to put it back. The clinical research, the pathways, and the precise dose, plainly explained.
The Energy Currency Of Life.
Found in every living cell. Without exception.
NAD+ (nicotinamide adenine dinucleotide) is one of the most important molecules in biology. It is found in every living cell on Earth, from bacteria to humans, and has been used by life to manage energy for over three billion years. Cells without NAD+ do not function. Cells with depleted NAD+ function poorly. The molecule sits beneath everything else.
Practically speaking, NAD+ does three things. It powers the mitochondria, the structures inside every cell responsible for converting food into usable energy. It activates the sirtuin family of proteins, the enzymes that regulate how cells age, repair themselves, and respond to stress. And it fuels the DNA repair machinery that fixes the thousands of small genetic errors your cells accumulate every day.
All three of those jobs depend on adequate NAD+ levels. When NAD+ is high, cells produce energy efficiently, sirtuins regulate ageing properly, and DNA repair keeps pace with damage. When NAD+ is low, all three systems falter. Energy production drops, ageing accelerates, and the genetic errors accumulate. The biology of ageing is, in significant part, the biology of declining NAD+.
Every living cell
From bacteria to humans, NAD+ is the universal energy coenzyme.
300+ reactions
NAD+ participates in over 300 distinct enzymatic processes daily.
Three core jobs
Energy production, sirtuin activation, DNA repair. The foundations.
Halved By Fifty.
Lower Still By Eighty.
The single most predictable shift in human biology.
NAD+ levels in human tissue follow a strikingly consistent decline curve across the population. The drop is gentle in your twenties and thirties. It accelerates in your forties. By the time most adults reach fifty, they have roughly half the NAD+ they had at twenty. By eighty, levels are typically below a third of youthful baseline.
This isn't speculation. It's been measured in human tissue samples across multiple studies, including Massudi et al. (2012) and Yoshino et al. (2018). The decline shows up in skin, muscle, brain, and liver tissue almost identically. It is one of the most reproducible findings in modern ageing research.
And the consequences are exactly what the previous section describes. As NAD+ falls, mitochondrial energy production declines. Sirtuin activity slows. DNA repair becomes less efficient. The cellular machinery that kept you well in your thirties is now running on a depleted battery, day after day, year after year.
"The biology of ageing is, in significant part, the biology of declining NAD+. The data is now beyond serious dispute."
NAD+ Levels By Age
Tissue concentration, % of youthful baseline
Massudi et al. 2012
How NAD+ Powers The Longevity Genes.
Two pathways. One coherent intervention.
NAD+ is the fuel. Sirtuins are the engines that burn it. Together they form the most studied longevity pathway in modern biology.
Sirtuins are a family of seven enzymes (SIRT1 through SIRT7) found in every human cell. Each one regulates a different aspect of cellular ageing: DNA repair, metabolic balance, mitochondrial health, gene expression, stress response. They are sometimes called the longevity genes, because activating them is one of the most reliable ways to extend healthy lifespan in the published research.
Every sirtuin in the family shares one critical dependency. They all require NAD+ to function. Without NAD+, sirtuins are inert. As NAD+ levels decline with age, sirtuin activity declines in lockstep. The cellular machinery that kept you well in your thirties is still present at fifty, but it is now starved of fuel.
Prime Ageing's two formulas target the two most studied members of this family. Each through a different mechanism. Together, they cover both the structural and the metabolic arms of the sirtuin programme.
SIRT6
The genome's structural guardian.
Primary RoleGenomic stability and chromatin maintenance.
DNA double-strand repair. Fixes the most dangerous form of genetic damage.
Telomere maintenance. Protects the protective caps at the ends of chromosomes.
Junk DNA silencing. Suppresses LINE1 elements that destabilise the genome with age.
Premium Fucoidan
A direct allosteric activator. The molecule binds SIRT6 and amplifies its activity.
SIRT1
The metabolic master regulator.
Primary RoleMetabolic balance, hormonal signalling, mitochondrial function.
Mitochondrial biogenesis. Tells cells to build new energy-producing structures.
Insulin sensitivity. Improves how the body handles blood glucose, particularly with age.
Hormonal regulation. Modulates oestrogen, cortisol, and circadian rhythm pathways.
Total Harmony 9
An indirect fuel pathway. NMN raises NAD+, which powers SIRT1's enzymatic engine.
"Two activators. Two sirtuins. The structural arm and the metabolic arm of the same longevity programme."
Why NMN, Specifically.
Of all the ways to raise NAD+, this is the one with the data.
You cannot supplement NAD+ directly. The molecule itself is too large and unstable to cross cell membranes intact, which is why every effective NAD+ intervention works through a precursor — a smaller molecule the body converts into NAD+ once it's inside cells.
Four precursors dominate the longevity research: NMN, NR, Nicotinamide, and direct NAD+ infusion. Of these, NMN has accumulated the most human clinical trial data over the past five years. The pivotal studies have been published in Science, NPJ Aging, and Nature Metabolism. The pharmacokinetics are well-characterised. The bioavailability is consistent across populations.
And critically, the doses required to elevate NAD+ meaningfully are now well-established. The published trials use clinical-grade doses in the hundreds of milligrams, and consistently report measurable NAD+ elevation, improvements in muscle insulin sensitivity, gait speed, grip strength, and biological-age markers. Cheaper, lower-dose NMN supplements simply don't deliver what the research requires. Total Harmony 9 is dosed in the clinically substantive range that the published research validates.
"NMN sits at the centre of the NAD+ supplementation universe. The most studied. The most reproducible. The most reliably dosed."
The Four Precursors
Compared in human research
NMN Lead
Nicotinamide Mononucleotide. The most-studied NAD+ precursor in human trials.
NR
Nicotinamide Riboside. Strong data in some markers, weaker in muscle outcomes.
Nicotinamide
Cheap, transient effect. Useful as a niacin source, weak as a longevity intervention.
NAD+ (direct)
Cannot cross cell membranes intact. Only effective via clinical IV infusion.
From Theory To Human Evidence.
Five years of published research, plainly summarised.
The landmark studies that moved NMN from animal models into rigorous human clinical validation. Year-stamped, peer-reviewed, and published in some of the most respected scientific journals in biology.
The First Major Human Trial
The first randomised, double-blind, placebo-controlled human trial of NMN in postmenopausal women with prediabetes. The study used skeletal muscle biopsies to analyse intracellular signalling pathways directly, the gold-standard methodology in metabolic research.
Doubling NAD+ in the Elderly
A randomised, double-blind, placebo-controlled trial in elderly men, designed to bridge the gap between NAD+ levels and functional physical performance. Targeting the demographic most vulnerable to the consequences of NAD+ depletion: men aged 65 and over.
Establishing The Therapeutic Range
The trial that addressed the critical question of optimal dosing in middle-aged adults. Designed to determine the dose range at which NMN supplementation reaches its functional ceiling, using biological-age tracking, walking distance tests, and SF-36 quality-of-life scoring.
NMN Confirmed As Lead Precursor
The first rigorous human comparison between NMN, NR, and Nicotinamide. The study mapped how each precursor enters the NAD+ pool over both acute (4-hour) and chronic (14-day) phases, including the role of the gut microbiome in precursor absorption.
What The Research Actually Shows.
Sorted by outcome, not by claim.
Four areas where human clinical trials have demonstrated measurable, peer-reviewed benefits from NMN supplementation. Each card names the trial, the cohort, and the specific finding.
Muscle Insulin Sensitivity
Randomised, double-blind, placebo-controlled trial in postmenopausal women with prediabetes. Skeletal muscle biopsies used to measure intracellular signalling directly.
25% improvement in insulin-stimulated glucose disposal (p < 0.05).
Grip Strength & Gait Speed
Twelve-week supplementation in healthy men aged 65 and over. Functional outcomes measured as clinical indicators of sarcopenia and biological frailty.
Significant improvement in left-hand grip strength and walking speed.
NAD+ Restoration
Twelve-week metabolomic analysis of blood NAD+ concentrations in elderly participants. Validation of chronic oral NMN bioavailability and salvage pathway uptake.
Blood NAD+ more than doubled from baseline (>100% increase).
Biological Age & Vitality
Sixty-day multicenter trial in middle-aged adults aged 40-65. Outcomes measured via Aging.Ai 3.0 biological age calculator and SF-36 health questionnaire.
Biological age held stable in NMN groups; SF-36 vitality scores significantly improved.
These findings represent peer-reviewed human clinical research, not animal studies or in-vitro work. Outcomes vary across populations, baselines, and protocols. Prime Ageing does not claim that Total Harmony 9 will replicate every finding above for every individual. We do claim that the formula is designed around the body of evidence these studies represent.
The Wider Cellular Effects.
Beyond the sirtuin pathway, the biology runs deeper.
NAD+ doesn't only fuel sirtuins. It powers a wider network of cellular maintenance systems, each with its own role in healthy ageing. Three are particularly well-studied.
Mitochondrial Biogenesis
Building new cellular power plants.
Mitochondria are the structures inside every cell that convert food into usable energy. Each cell typically contains hundreds, and the number declines with age. NAD+ activates PGC-1α, a regulatory protein that signals cells to build new mitochondria.
When NAD+ levels rise through NMN supplementation, PGC-1α activity rises with it. The cell responds by increasing both the number and quality of its mitochondria, restoring the energy-production capacity that age has eroded.
PGC-1α · Mitochondrial Density · Cellular Energy
DNA Repair
Fixing the damage your cells accumulate every day.
Your DNA suffers thousands of small breaks every day from UV radiation, metabolic byproducts, and ordinary cellular activity. The body has a dedicated repair system: PARP enzymes, which detect and patch the damage. PARPs are entirely dependent on NAD+ to function.
As NAD+ levels decline with age, PARP activity falters. Damage accumulates faster than the cell can repair it. Genetic instability rises. Restoring NAD+ keeps the repair system fuelled, allowing it to keep pace with the damage.
PARP-1 · Genomic Stability · Damage Response
Circadian Rhythm
Restoring the daily clock that age disrupts.
NAD+ levels naturally oscillate across the 24-hour day, and this rhythm is tightly linked to the body's master circadian clock. The BMAL1 and CLOCK proteins that govern your sleep-wake cycle work in partnership with sirtuins, which require NAD+ to function.
When NAD+ falls, the rhythm flattens. Sleep quality drops. Energy timing becomes erratic. Raising NAD+ helps restore the proper amplitude of the daily cycle, supporting deeper sleep at night and steadier energy during the day.
BMAL1 · CLOCK · Sleep-Wake Cycle
"One molecule. Many systems. NAD+ sits closer to the foundation of cellular biology than almost anything else science has identified."
Properly Sourced. Properly Made.
Not all NMN is created equal.
The clinical evidence for NMN is only as strong as the molecule you actually take. Sourcing, purity, and sensible use matter as much as the dose.
The Source
Pharmaceutical-grade NMN, third-party verified.
Total Harmony 9 uses NMN standardised to ≥99% purity, sourced from facilities that supply pharmaceutical-grade material.
The molecule is the same one used in the published clinical research. Not synthesised differently, not standardised loosely, not adulterated with cheaper precursors that some lower-cost brands rely on.
≥99% Pure NMN
Regulatory Status
UK food supplement, properly classified.
NMN is sold in the UK as a food supplement, manufactured to the same Good Manufacturing Practice (GMP) standards as every clinical-grade supplement on the British market. As of late 2025, the FDA confirmed NMN's status as a supplement category in the United States as well.
UK GMP-Certified Facility
Sensible Use
A few groups should speak to a clinician first.
NMN has an excellent human safety profile, with clinical trials showing tolerance up to 1,250mg daily without notable adverse effects. For most adults, the only sensible note is to take it consistently with food.
As with any supplement, those who are pregnant, breastfeeding, undergoing active cancer treatment, or on prescription medication should speak to their GP before starting. Not because of known risks, but because individual circumstances matter.
Speak to your GP or pharmacist
Total Harmony 9 is built around the same NMN molecule used in the published human clinical research. Quality is the unspoken layer beneath every claim on this page.
Why The Research Started With Women.
Menopause is when NAD+ decline accelerates. The science noticed first.
The first major human clinical trial of NMN, published in Science in 2021, was not conducted on a general adult population. It was conducted specifically on postmenopausal women. The choice was deliberate.
Falling oestrogen accelerates the cellular ageing pathways NMN was designed to address. Insulin sensitivity declines. Mitochondrial efficiency drops. The NAD+ salvage pathway, already weakening with age, weakens further. The post-menopausal body is exactly the body NMN supplementation has the most ground to recover.
For women in perimenopause and the years after, NMN is not a generic longevity hack. It is a research-grounded intervention into one of the specific biological transitions the body is moving through. Total Harmony 9 was built around this evidence: 9 clinical actives, anchored by NMN, formulated for the precise demands of midlife.
"The clinical evidence for NMN in midlife women is stronger, in some respects, than the evidence for the general adult population. The published research started here, and the most rigorous human data still sits here."
Yoshino et al., 2021
"Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women."
Published in Science, this was the first major randomised, double-blind, placebo-controlled human trial of NMN. The cohort was deliberately specific: 25 postmenopausal women with prediabetes. The study used skeletal muscle biopsies to analyse intracellular signalling pathways directly, the gold-standard methodology in metabolic research.
The trial was designed to answer a single question: does oral NMN supplementation produce measurable metabolic effects in the population most affected by NAD+ decline?
25% improvement in muscle insulin sensitivity (p < 0.05), with significant increases in AKT and mTOR signalling.
The Case For NMN. Plainly.
After thirteen sections of evidence, the conclusion is straightforward.
The biology is settled. NAD+ declines steeply with age, halving by fifty and dropping further from there. The cellular machinery that runs on it (mitochondria, sirtuins, DNA repair, circadian rhythm) all suffer in lockstep. The decline is one of the most reproducible findings in modern ageing research.
The intervention is established. Of the available NAD+ precursors, NMN has the most peer-reviewed human clinical data. Yoshino 2021, Igarashi 2022, Yi 2023, Christen 2025. Published in Science, NPJ Aging, and Nature Metabolism. The doses required are well-characterised. The safety profile is excellent.
The formula matters. Total Harmony 9 is built around the NMN molecule used in the published clinical research, dosed in the clinically substantive range, supported by eight additional co-actives chosen for their relevance to midlife biology. The same molecule the science describes.
Honest Answers
to the questions we hear most.
The questions UK adults actually ask before adding NMN to their daily routine. Plain answers, properly sourced.
NMN is a precursor molecule the body converts into NAD+, the coenzyme every cell uses to produce energy, repair DNA, and run the sirtuin family of longevity proteins. Supplementing with NMN raises NAD+ levels, particularly in adults over fifty whose levels have already declined.
The published human clinical trials show measurable benefits across muscle insulin sensitivity, grip strength, gait speed, and biological age markers. The mechanism is well-characterised. The outcomes vary by individual, but the underlying biology is no longer in dispute.
No. They are all NAD+ precursors, but they work through different pathways and have different clinical profiles. NMN has the most peer-reviewed human clinical data, particularly for muscle and metabolic outcomes. NR (Nicotinamide Riboside) has strong data in some markers, particularly brain NAD+. Nicotinamide is cheaper and produces only transient effects.
The 2025 Christen et al. study in Nature Metabolism compared all three head-to-head and confirmed NMN and NR as the two lead precursors for sustained NAD+ elevation. NMN's particular strength is in the muscle and metabolic findings.
Honestly, it varies. Some people report noticeably improved energy, sleep quality, and morning steadiness within two to four weeks. Others notice nothing subjective in the short term, but blood biomarkers show NAD+ rising regardless.
The clinical research focuses on measurable physiological changes over months rather than day-one feelings. Improved insulin sensitivity, better grip strength, biological age stability — these are the outcomes the trials measure. Subjective improvements are a bonus, not the goal.
NMN is genuinely expensive to produce. The molecule is synthesised through a multi-step process, and pharmaceutical-grade purity (which is what the published clinical research uses) costs significantly more than lower-grade material. Most very-cheap NMN supplements are either underdosed or use lower-purity material that doesn't behave like the molecule used in the trials.
A clinical-grade dose costs what it costs. Anything dramatically below that price point is usually compromising on either dose, purity, or both.
Most people take it in the morning with food. NAD+ levels naturally peak in the morning hours, so timing the supplementation to align with the body's circadian rhythm is sensible.
Taking it with a meal also improves stomach tolerance. Total Harmony 9 is designed to be taken with breakfast or shortly after.
Subjective improvements (energy, sleep, morning alertness) typically appear within two to four weeks if they appear at all. Some people notice them, some don't.
The objective biological changes — measurable NAD+ rises, insulin sensitivity improvements, grip strength gains — were observed in the published clinical trials between 8 and 12 weeks of consistent supplementation. Like most longevity interventions, NMN works through compounding rather than acute effects. Months matter more than days.
Yes, in most cases. NMN sits comfortably alongside common supplements like vitamin D, magnesium, omega-3s, and protein supplementation. There are no widely-reported interactions between NMN and other longevity supplements like resveratrol, fucoidan, or creatine.
Some people stack NMN with trans-resveratrol on the theory that the two work together to amplify sirtuin activation, though the human evidence for this synergy is limited. The simplest sensible approach: take NMN consistently and judge it on its own terms before adding other things.
The strongest single piece of human clinical evidence for NMN was conducted specifically on postmenopausal women. Yoshino et al. 2021, published in Science, demonstrated significant improvements in muscle insulin sensitivity in this exact population, with no notable adverse effects over 10 weeks.
NMN is not a hormone, does not affect oestrogen levels directly, and does not interact with HRT in any documented way. For women navigating perimenopause and the years after, NMN is one of the better-evidenced supplements available — which is why it sits at the centre of Total Harmony 9.
There are no documented interactions between NMN and hormone replacement therapy. NMN is not a hormone and does not influence oestrogen, progesterone, or testosterone pathways directly. Many of Prime Ageing's customers take both alongside each other.
That said, if you are on HRT or any prescription medication, the sensible course is to mention any new supplement to your GP or prescribing clinician. Not because of known risks, but because individual circumstances matter.
Yes. The biological rationale becomes stronger after fifty, when NAD+ has already halved from youthful baseline, but the published research includes adults from age 40 upwards. NAD+ decline begins in the late thirties and accelerates through the forties, so starting earlier rather than later is reasonable for adults serious about preventive longevity.
That said, the urgency is greater after fifty. For adults in their thirties, food, movement, and sleep should remain the primary levers; NMN sits as a complementary precision layer rather than a foundational one.
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