NMN vs Creatine: Which Matters More After 40?

If you are over 40 and reading about longevity supplements, you will run into the same two names again and again: NMN and creatine. One is the poster molecule of modern anti-ageing science. The other is a 30-year-old sports supplement your gym-mad nephew keeps in a tub next to the protein powder. On paper they could not look more different — and yet people keep asking the same question: which one actually earns a place in my routine after 40?

For the full background, start with our pillar guide to longevity supplements and our NMN benefits, side effects and dosage guide. To compare products, browse the NMN supplements and wider anti-ageing and longevity ranges, including NMN Pro 1000.

The honest answer is that they are not really competitors. They work on two separate energy systems, they are backed by two very different tiers of evidence, and they cost wildly different amounts. But if your budget only stretches to one, the decision is genuinely straightforward once you see the data side by side.

This guide compares NMN and creatine across muscle, brain, endurance, metabolic health, safety, cost and — most importantly — evidence quality.

NMN vs Creatine at a Glance

Before the detail, here is the comparison in one table. Prices are indicative UK retail figures for a typical 30-day supply and will vary by brand and purity — we break this down properly in our longevity stack cost guide.

What Is NMN and How Does It Work?

Nicotinamide mononucleotide (NMN) is a nucleotide derived from vitamin B3. It occurs naturally in trace amounts in foods such as broccoli, avocado, cucumber and edamame, and it exists in every cell in your body. Its job is simple to describe and enormously important: it is the immediate precursor to nicotinamide adenine dinucleotide (NAD⁺).

NMN and the NAD⁺ pathway

NAD⁺ is a coenzyme involved in several hundred enzymatic reactions. It shuttles electrons during energy production in the mitochondria, and it is consumed as a substrate by two families of enzymes closely tied to ageing biology: the sirtuins (which regulate gene expression and metabolic stress responses) and the PARPs (which carry out DNA repair).

Your body makes NAD⁺ mainly through the salvage pathway, recycling nicotinamide back into NMN and then into NAD⁺. Supplementing with NMN feeds that pathway directly. If you want the full mechanism, our NAD⁺ supplement guide and our explainer on the hallmarks of ageing go considerably deeper.

What happens to NAD⁺ after 40

NAD⁺ concentrations decline in the tissues of ageing animals, and the mechanisms behind that decline — increased consumption by enzymes such as CD38 and the PARPs, alongside possible reductions in synthesis — are an active area of research. A widely cited review in Experimental Gerontology summarises the evidence and, importantly, is candid about how limited the direct human data still are.^[8]

That decline matters because it overlaps almost exactly with the period when people start noticing the things that bring them to an article like this: slower recovery, flatter energy, worse sleep, and a body composition that shifts even when the scales do not. It is also the window in which muscle loss accelerates — a review in Current Opinion in Clinical Nutrition and Metabolic Care reports that muscle mass falls by roughly 3–8% per decade after the age of 30, with the rate increasing again after 60.^[7]

What the human trials on NMN actually show

This is where careful reading matters. NMN has a genuinely encouraging early evidence base and a genuinely thin one, depending on which outcome you look at.

It reliably raises blood NAD⁺

The most consistent finding across trials is that oral NMN increases circulating NAD⁺. In a randomised, multicentre, double-blind, placebo-controlled trial of 80 healthy middle-aged adults, participants took placebo or 300 mg, 600 mg or 900 mg of NMN daily for 60 days. Blood NAD⁺ rose significantly in all three NMN groups at both day 30 and day 60, with the 600 mg and 900 mg groups higher than 300 mg — the authors concluded efficacy peaked at around 600 mg daily.^[5]

Aerobic capacity and endurance

A six-week randomised, double-blind trial published in the Journal of the International Society of Sports Nutrition randomised 48 recreationally trained runners to placebo or 300, 600 or 1200 mg of NMN per day alongside their normal training. Oxygen uptake and ventilatory threshold improved significantly in the 600 mg and 1200 mg groups compared with placebo, with the effect appearing dose-dependent.^[4] Notably, the authors attributed the improvement to better oxygen utilisation in skeletal muscle rather than to changes in the heart or lungs. If endurance is your priority, our guide to supplements for endurance athletes and our piece on Zone 2 training for longevity are worth reading alongside this.

Walking distance and self-reported health

In the same 80-person dose-ranging trial, six-minute walk test distance increased significantly versus placebo at both day 30 and day 60 across the NMN groups, and SF-36 quality-of-life scores improved.^[5] These are meaningful functional outcomes rather than surrogate blood markers — which is why this trial is cited so often.

Insulin sensitivity

A 10-week randomised, placebo-controlled trial published in Science gave 250 mg of NMN daily to postmenopausal women with prediabetes who were overweight or obese. Insulin-stimulated glucose disposal, measured with a hyperinsulinaemic-euglycaemic clamp, and skeletal muscle insulin signalling both increased with NMN and did not change with placebo.^[6] The trial was small (25 participants) and has been debated in the literature — a published comment raised concerns that baseline liver fat differed markedly between groups^[15] — but it remains the most rigorous metabolic study of NMN in humans to date.

Where the NMN evidence falls down

Here is the finding that most NMN marketing pages leave out. A 2025 systematic review and meta-analysis in the Journal of Cachexia, Sarcopenia and Muscle pooled 10 randomised controlled trials of NMN and nicotinamide riboside in older adults (mean ages 60.9 to 83 years). Across every muscle outcome examined, NMN showed no significant effect: skeletal muscle index, handgrip strength, gait speed and the five-time chair stand test all came back null, and a narrative synthesis found no improvement in knee extension strength, short physical performance battery scores or thigh muscle mass. The authors concluded that current evidence does not support NMN for preserving muscle mass and function in adults over 60.^[3]

What Is Creatine and How Does It Work?

Creatine is a naturally occurring compound synthesised in the liver, kidneys and pancreas from three amino acids — glycine, arginine and methionine. You also get it from food, principally red meat and fish, at roughly 1–2 g per day on an omnivorous diet. Around 95% of the body's creatine sits in skeletal muscle, most of it as phosphocreatine.

The phosphocreatine energy system

Every muscle contraction, every thought and every heartbeat is paid for in ATP. But cells hold only a few seconds' worth of ATP at any moment. Phosphocreatine is the buffer: it donates a phosphate group to regenerate ATP almost instantly, which is what allows you to produce high force for the first 10–20 seconds of an effort before slower energy systems catch up.

Supplementing with creatine raises intramuscular creatine and phosphocreatine stores, typically by 20–40% depending on your starting point. Vegetarians and vegans, who consume little or no dietary creatine, generally start lower and respond more strongly — a point we explore in our guide to vegan longevity supplements.

Creatine and muscle after 40

This is the strongest single dataset in the entire NMN vs creatine comparison. A meta-analysis in the Open Access Journal of Sports Medicine pooled 22 randomised controlled trials of creatine supplementation during resistance training in older adults — 721 participants with mean ages across studies of 57 to 70, training two to three days a week for between seven and 52 weeks.

Compared with placebo plus the same training, creatine produced:

• A mean increase in lean tissue mass of 1.37 kg (95% CI 0.97–1.76)
• Greater chest press strength (standardised mean difference 0.35)
• Greater leg press strength (standardised mean difference 0.24)

All three results were statistically significant.^[2] To be clear about what that means: creatine did not build muscle on its own. It amplified the effect of resistance training. The training is doing the heavy lifting — creatine makes each session slightly more productive, and those small increments compound across a year.

Creatine and the brain

The brain is metabolically expensive and runs its own creatine kinase system. Two independent systematic reviews have now examined whether supplementation translates into measurable cognitive benefit.

A meta-analysis in Nutrition Reviews found that creatine improved memory performance, with the clearest effects in older adults aged 66–76 and no significant effect in young adults.^[9] A separate meta-analysis of 16 RCTs in Frontiers in Nutrition reported significant improvements in memory (SMD 0.31, 95% CI 0.18–0.44) and processing speed, though no significant change in overall global cognition or executive function.^[10]

The effect sizes are modest and the trials are small. But "modest and replicated" beats "large and unreplicated" every time, and this is a domain where NMN currently has no comparable evidence in humans.

Creatine, women and menopause

Creatine research has historically been done in young men, which is a genuine limitation. A review in Nutrients focusing on women across the lifespan makes an important physiological point: women have roughly 70–80% lower endogenous creatine stores than men, and creatine kinetics shift with oestrogen across the menstrual cycle and through menopause.

The review reports that premenopausal women appear to benefit for strength and exercise performance, and that postmenopausal women may see benefits in skeletal muscle size and function at higher doses (0.3 g per kg body weight per day), with favourable bone effects when combined with resistance training.^[11] If you are navigating perimenopause or menopause, read this alongside our guides to longevity supplements for women over 40 and NMN and menopause.

Creatine's safety record

The International Society of Sports Nutrition position stand — the most comprehensive review of the creatine literature available — concludes that creatine monohydrate is the most effective ergogenic nutritional supplement currently available for increasing high-intensity exercise capacity and lean body mass during training. On safety, it states that short and long-term supplementation, at intakes up to 30 g per day for five years, has been safe and well tolerated in healthy individuals and in a range of patient populations from infants to the elderly.^[1]

Thirty grams a day for five years is roughly six times the standard maintenance dose sustained for six times longer than most people will ever take it. That is an unusually generous safety margin for any supplement.

NMN vs Creatine: Head-to-Head on the Eight Things That Matter After 40

1. Muscle mass and strength

Winner: creatine, decisively. A 1.37 kg lean tissue advantage across 22 trials in older adults^[2] versus a null meta-analysis for NMN across every muscle endpoint in over-60s.^[3] This is not close.

2. Endurance and aerobic capacity

Winner: NMN. The runner trial showed dose-dependent improvements in oxygen uptake and ventilatory threshold at 600 and 1200 mg daily.^[4] Creatine's benefits are concentrated in short, high-intensity efforts; it does little for steady-state aerobic performance and the extra intracellular water can be a mild disadvantage in weight-bearing endurance sport.

3. Everyday energy and fatigue

Slight edge: NMN, but subjective. SF-36 quality-of-life scores improved in NMN trials.^[5] Self-reported energy is notoriously placebo-sensitive, so treat this cautiously. Manage your expectations with our guide to how long supplements take to work.

4. Brain and cognition

Winner: creatine. Two meta-analyses point to memory and processing speed benefits, with the strongest signal in older adults.^[9][10] NMN has no comparable human cognitive dataset.

5. Metabolic health

Winner: NMN. The Science trial remains the only randomised clamp-verified demonstration of improved muscle insulin sensitivity from either compound.^[6] Small sample, contested analysis — but creatine has nothing equivalent.

6. Bone health

Slight edge: creatine. Effects on bone mineral density in older adults have been mixed, but creatine combined with resistance training has shown favourable bone outcomes in postmenopausal women.^[11] NMN has no human bone data.

7. Evidence quality

Winner: creatine, by a very wide margin. Creatine has hundreds of trials and multiple independent meta-analyses spanning three decades. NMN has around 10–15 human RCTs, most under 12 weeks, most with fewer than 100 participants, and several funded by ingredient manufacturers. That does not make NMN ineffective — it makes it unproven, which is a different thing.

8. Cost per month

Winner: creatine, by roughly five to ten times. A 500 g tub of creatine monohydrate lasts around 100 days at 5 g/day and costs single-digit pounds per month. High-purity NMN typically runs £25–£60 monthly. Our breakdowns of the cheapest NMN in the UK and why supplements are expensive explain where the money actually goes.

Two Different Energy Systems: Why This Isn't Really Either/Or

The framing of "NMN vs creatine" is popular because it makes a tidy headline, but biologically it is a category error. Creatine works on the ATP–phosphocreatine system: how quickly you can recycle energy currency during a brief, hard effort. NMN works upstream on NAD⁺: how well your cells convert fuel into that energy currency in the first place, and how well they handle repair and signalling while doing it.

Think of it as the difference between the size of your car's fuel injectors and the condition of the engine. They are not substitutes.

Can you take NMN and creatine together?

Yes. There is no known interaction, no shared absorption pathway that would cause competition, and no published safety signal from combining them. What there also is not is a published human trial testing the combination directly — so anyone claiming a proven synergistic effect is going beyond the evidence.

Practically, most people who take both do the following: creatine 3–5 g at any time of day, and NMN in the morning. Our guides to taking supplements together and the supplement timing chart cover the sequencing in detail. If you are building a broader routine, see our longevity stack and minimal supplement stack guides.

Which Should You Prioritise After 40?

Use the framework below. In every scenario, the assumption is that you are already doing resistance training at least twice a week, in line with NHS physical activity guidance.^[12] Neither supplement does much without that foundation.

If your goal is muscle, strength or body composition

Start with creatine. Five grams a day, every day, indefinitely. Revisit NMN in six months once creatine is a habit. See creatine for longevity for the full case.

If your goal is endurance or metabolic health

NMN has the more relevant data here — the runner trial and the insulin sensitivity trial both point in that direction.^[4][6] Start at 300–600 mg daily and give it 12 weeks.

If you are on a tight budget

Creatine, without hesitation. It is the highest evidence-to-cost ratio in the entire supplement aisle. Our cheap longevity stack is built around exactly this logic.

If you are a woman over 40 or in perimenopause

Creatine deserves a hard look given the substantially lower baseline stores in women and the bone and mood signals in the literature.^[11] Many women then add NMN for the metabolic and energy side. See longevity supplements for women over 40.

If you are a man over 50

Prioritise creatine for sarcopenia risk, then consider NMN. Our guide to longevity supplements for men over 50 sets out a sensible order of operations.

If you are in your 30s

Creatine still first — the muscle you build in your thirties is the muscle you spend in your seventies. See longevity supplements in your 30s.

If you are vegetarian or vegan

Creatine, and it is not close. Plant-based diets supply almost no dietary creatine, so baseline muscle stores are lower and the response to supplementation is typically larger.

How to Take NMN and Creatine

NMN dosage and timing

Human trials have used 250 mg to 1200 mg daily. The dose-ranging trial found blood NAD⁺ and functional outcomes peaked at around 600 mg daily, with 900 mg offering no clear additional benefit.^[5] Most people do well starting at 250–300 mg and building up.

Timing: morning is the conventional choice, on the basis that NAD⁺ metabolism follows a circadian rhythm. This is a reasonable inference rather than a proven protocol. Our detailed guides cover when to take NMN, NMN with or without food, NMN dosage by age, sublingual NMN and whether you need TMG alongside NMN.

Creatine dosage and loading

Two approaches, both supported by the ISSN position stand:^[1]

• Standard: 3–5 g daily. Muscle stores saturate in roughly three to four weeks. Simplest and gentlest on the gut.
• Loading: 20 g daily split into four 5 g doses for five to seven days, then 3–5 g daily. Saturates stores in about a week but more likely to cause bloating.

Take it with water, at any time of day, on training and rest days alike. Consistency matters far more than timing.

A sensible 12-week starting protocol

Staggering the two is deliberate: if you start both on the same day and feel different, you will never know which one was responsible. For a broader onboarding plan see how to start longevity supplements, and if you want an objective before-and-after measure, our biological age guide explains what is and isn't worth testing.

Side Effects, Safety and Who Should Avoid Them

NMN safety

Across published human trials, NMN has been well tolerated at doses up to 1200 mg daily for six weeks and 900 mg daily for 60 days, with no serious adverse events attributed to the supplement.^[4][5] Reported side effects are generally mild and transient — nausea, loose stools, flushing — and often occur at higher doses.

In May 2026, the European Food Safety Authority published a scientific opinion concluding that β-NMN is safe for use in food supplements as a source of niacin at up to 300 mg per day, for adults, excluding pregnant and lactating women.^[13] That figure is a regulatory safety assessment for a specific application, not a ceiling above which harm has been demonstrated — but it is the most authoritative European position currently available and worth knowing if you are considering higher doses. See also our article on whether you can take too much NMN and what happens when you stop taking NMN.

Creatine safety and the kidney myth

The persistent belief that creatine damages the kidneys comes from a misreading of blood tests. Creatine breaks down into creatinine, which is the marker clinicians use to estimate kidney function. Supplementing raises creatinine slightly without any change in actual kidney function — the number moves, the organ does not. The ISSN position stand reviewed this evidence directly and found no adverse effects on kidney function in healthy individuals at recommended doses.^[1]

Two practical notes. First, tell your GP you take creatine before any blood test that includes renal function, so results are interpreted correctly. Second, if you already have diagnosed kidney disease, discuss creatine with your doctor rather than self-prescribing.

Genuine creatine side effects are limited to mild gastrointestinal upset (usually from taking too much at once) and an initial 0.5–1.5 kg gain in body weight from intracellular water. That water is inside the muscle, not under the skin, and it is not fat.

Who should be cautious with either

• Pregnancy and breastfeeding: avoid both. Neither has adequate safety data, and the EFSA opinion on NMN explicitly excludes these groups.^[13]
• Kidney or liver disease: speak to your doctor first.
• Anyone on prescription medication: check with your pharmacist, particularly if you take medicines that affect renal function.
• Active or recent cancer: discuss NMN with your oncology team. NAD⁺ metabolism is relevant to cell proliferation and the long-term implications in this context are not established.
• Under 18s: neither is appropriate outside clinical supervision.

Choosing Quality NMN and Creatine in the UK

What to look for in NMN

• Purity of 99%+, verified by a current certificate of analysis — see our guide to reading a supplement certificate of analysis.
• Independent batch testing by a third-party laboratory, not just the manufacturer's own quality control. More on this in third-party tested supplements.
• Beta form (β-NMN), which is the biologically active isomer.
• Minimal fillers. Our article on supplement fillers explains which are inert and which are padding.
• Clear labelling of dose per capsule, so you are not comparing a 250 mg product against a 500 mg one on price alone.

If you are comparing brands, our reviews of Vitality Pro NMN, Renue by Science and Youth & Earth NMN are a useful starting point, and where to buy NMN in the UK covers the retail landscape including Boots and Holland & Barrett.

What to look for in creatine

Buy creatine monohydrate. Not hydrochloride, not ethyl ester, not buffered, not "advanced". The ISSN position stand is unambiguous that monohydrate is the most effective form,^[1] and it is also the cheapest. Look for Creapure® or an equivalent purity certification, and a short ingredient list.

NMN's regulatory status in the UK

NMN falls within the scope of UK novel food regulation, which applies to ingredients not widely consumed in the UK or EU before May 1997. It is not banned, and it remains available from UK retailers, but it has not completed the Food Standards Agency authorisation process. In practical terms this means UK sellers cannot make specific health claims about NMN — which is why reputable retailers describe the research rather than promising outcomes. The May 2026 EFSA opinion on β-NMN moves the European picture forward, though UK authorisation runs on its own track.^[13] Creatine, by contrast, is a long-established food supplement ingredient with no novel food issues.

Five Common Mistakes People Make

1. Buying NMN before fixing training, protein and sleep. No supplement outperforms two resistance sessions a week and adequate protein. Both compounds amplify a good foundation; neither replaces one.
2. Expecting creatine to work without training. The 1.37 kg lean mass figure comes from trials that combined creatine with resistance training.^[2] On its own, creatine mostly just fills muscle cells with water.
3. Under-dosing NMN to save money. A 125 mg capsule is below every dose used in the positive trials. If the budget only stretches to a token dose, spend it on creatine instead.
4. Starting five things at once. You lose all ability to attribute effects. Stagger, and keep a simple log.
5. Quitting at four weeks. Creatine needs three to four weeks to saturate; NMN trials ran for six to 12 weeks minimum. Judge either one before that and you are judging noise.

The Verdict: NMN vs Creatine After 40

If you take one thing from this comparison, take this: creatine is the sure thing and NMN is the interesting bet.

Creatine has three decades of randomised trials, multiple independent meta-analyses, a documented 1.37 kg lean tissue advantage in older adults training with weights, replicated memory benefits, an exceptional safety record and a cost of a few pounds a month.^[1][2][9] After 40, when muscle is quietly leaving at 3–8% per decade,^[7] that combination is difficult to argue with.

NMN is doing something creatine cannot. It reliably raises NAD⁺, improved aerobic capacity in trained runners, increased six-minute walk distance in middle-aged adults and improved muscle insulin sensitivity in postmenopausal women with prediabetes.^[4][5][6] But the 2025 meta-analysis showing no muscle benefit in over-60s is a real result that deserves to sit alongside the positive ones, not be buried beneath them.^[3]

So: creatine first, for almost everyone. Add NMN when the basics are locked in and the budget allows — and give it a fair 12 weeks before you decide. Ready to start? Explore our NMN supplements collection, read the full NMN benefits, side effects and dosage pillar guide, or see the specification for NMN Pro 1000.

Frequently Asked Questions

References

1. Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition. 2017;14:18. https://pmc.ncbi.nlm.nih.gov/articles/PMC5469049/
2. Chilibeck PD, Kaviani M, Candow DG, Zello GA. Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis. Open Access Journal of Sports Medicine. 2017;8:213–226. https://pmc.ncbi.nlm.nih.gov/articles/PMC5679696/
3. Prokopidis K, Moriarty F, Bahat G, McLean J, Church D, Patel H. The effect of nicotinamide mononucleotide and riboside on skeletal muscle mass and function: a systematic review and meta-analysis. Journal of Cachexia, Sarcopenia and Muscle. 2025;16:e13799. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12022230/
4. 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. Journal of the International Society of Sports Nutrition. 2021;18(1):54. https://pmc.ncbi.nlm.nih.gov/articles/PMC8265078/
5. Yi L, Maier AB, Tao R, 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. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9735188/
6. Yoshino M, Yoshino J, Kayser BD, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021;372(6547):1224–1229. https://www.science.org/doi/10.1126/science.abe9985
7. Volpi E, Nazemi R, Fujita S. Muscle tissue changes with aging. Current Opinion in Clinical Nutrition and Metabolic Care. 2004;7(4):405–410. https://pmc.ncbi.nlm.nih.gov/articles/PMC2804956/
8. McReynolds MR, Chellappa K, Baur JA. Age-related NAD⁺ decline. Experimental Gerontology. 2020;134:110888. https://pmc.ncbi.nlm.nih.gov/articles/PMC7442590/
9. Prokopidis K, Giannos P, Triantafyllidis KK, Kechagias KS, Forbes SC, Candow DG. Effects of creatine supplementation on memory in healthy individuals: a systematic review and meta-analysis of randomized controlled trials. Nutrition Reviews. 2023;81(4):416–427. https://academic.oup.com/nutritionreviews/article/81/4/416/6671817
10. Xu C, Bi S, Zhang W, Luo L. The effects of creatine supplementation on cognitive function in adults: a systematic review and meta-analysis. Frontiers in Nutrition. 2024;11:1424972. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11275561/
11. Smith-Ryan AE, Cabre HE, Eckerson JM, Candow DG. Creatine supplementation in women's health: a lifespan perspective. Nutrients. 2021;13(3):877. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7998865/
12. National Health Service. Physical activity guidelines for adults aged 19 to 64. NHS, UK. https://www.nhs.uk/live-well/exercise/physical-activity-guidelines-for-adults-aged-19-to-64/
13. EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA). Safety of beta-nicotinamide mononucleotide (β-NMN) pursuant to Regulation (EU) 2015/2283 and the bioavailability of nicotinamide from this source. EFSA Journal. 2026;24(5):e10007. https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2026.10007
14. Zhang N, et al. Emerging strategies, applications and challenges of targeting NAD⁺ in the clinic. Nature Aging. 2025. https://www.nature.com/articles/s43587-025-00947-6
15. Comment on "Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women". Science. 2021. https://www.science.org/doi/10.1126/science.abj1696