NMN and Menopause: What's Known

Much of what you will read implies that NMN eases hot flushes, rebalances hormones or slows ovarian ageing. The honest position is narrower and more interesting: one well-conducted randomised trial in postmenopausal women, a body of supportive non-human research, and a great many open questions.

Wider context sits in our longevity supplements guide, the anti aging supplements range and longevity supplements for women over 40. For the compound itself, see NMN benefits, side effects and dosage, the NMN supplements collection and NMN Pro 1000.

This guide sets out what is known, what is plausible but unproven, and what is simply marketing.

What NMN and NAD⁺ actually are

Nicotinamide mononucleotide is a small molecule derived from vitamin B3 and a direct precursor to nicotinamide adenine dinucleotide (NAD⁺), a coenzyme every cell depends on.

NAD⁺ has two broad jobs. It shuttles electrons during energy metabolism, which is how mitochondria convert food into ATP. It is also consumed as a substrate by enzymes involved in DNA repair (PARPs), signalling (CD38) and metabolic regulation (sirtuins). That second role matters, because it means NAD⁺ is used up rather than recycled indefinitely.

How NMN becomes NAD⁺

The dominant route in adult tissue is the salvage pathway: nicotinamide is converted to NMN by NAMPT, then to NAD⁺ by NMNAT enzymes. Taking NMN orally is intended to feed that pathway a step further along than plain vitamin B3 would.

Whether that step gives a real advantage in humans is still debated — some researchers argue oral NMN is broken down to nicotinamide riboside or nicotinamide before absorption, meaning the tissue receiving it may not be the tissue you were aiming at. Our NAD supplement guide covers the precursor debate, and Tru Niagen vs NMN compares the two most common options.

Does NAD⁺ really fall with age?

This is the foundation the whole category rests on, so it deserves scrutiny. Declines have been reported in human skin, brain, liver, heart and immune cells [1,2].

But a 2022 review in Nutrients argued the evidence for a universal, whole-body NAD⁺ decline is thinner than the marketing suggests and is often based on a single tissue or cell type [3]. A 2025 review in Nature Metabolism reached a similar conclusion: consistent age-related decline in humans has been demonstrated in only a limited number of studies, and clinical trials of NAD⁺ precursors have so far shown limited efficacy [4]. A 2026 follow-up in the same journal reported that whole-blood NAD⁺ levels do not vary with age or with lifestyle interventions [22] — which matters, because blood is what commercial NAD⁺ tests measure.

The fair summary: NAD⁺ almost certainly falls in some tissues, the size and universality of that fall is contested, and raising blood NAD⁺ is not the same as fixing whatever NAD⁺ problem a given tissue has. Broader context is in the hallmarks of ageing.

Why menopause is a plausible research target

Menopause is defined as twelve consecutive months without a period. In the UK it typically occurs around age 51, though perimenopause — the symptomatic run-up — often begins in the mid-forties and can last several years. NICE guideline NG23, updated in November 2024 and amended in April 2026, is the UK reference standard [5].

The metabolic shift

The reason researchers connect NAD⁺ biology to midlife women is not hormonal — it is metabolic. The American Heart Association's 2020 scientific statement documented that the menopause transition is accompanied by adverse changes in body fat distribution, lipids and lipoproteins, and structural and functional measures of vascular health, and that these accelerate cardiovascular risk independently of chronological ageing [6].

In plain terms: fat redistributes toward the abdomen, insulin sensitivity tends to worsen, lipids deteriorate and arteries stiffen. Those are precisely the outcomes NAD⁺ precursors have been tested against. That overlap is the entire scientific rationale — not any direct effect on oestrogen.

The mitochondrial angle

Fatigue, exercise intolerance and reduced recovery are common midlife complaints, and mitochondrial function is a reasonable place to look. NAD⁺ is indispensable to oxidative phosphorylation, so a molecule supporting NAD⁺ availability is at least mechanistically relevant.

Mechanistic relevance is not proof of benefit, and this is where most menopause-and-NMN content goes wrong. A pathway being involved does not mean supplementing an input to that pathway changes how you feel.

What menopause is not

What the human evidence actually shows

The one trial conducted in postmenopausal women

The most relevant study by a wide margin was published in Science in 2021 by Yoshino and colleagues at Washington University School of Medicine [7].

Design

Twenty-five postmenopausal women who were overweight or obese and had prediabetes were randomised to 250 mg of oral NMN daily or placebo for ten weeks, double-blind and placebo-controlled. The primary outcome was muscle insulin sensitivity measured with a hyperinsulinaemic–euglycaemic clamp.

What it found

Muscle insulin sensitivity improved meaningfully in the NMN group relative to placebo. The researchers also observed increased expression of platelet-derived growth factor receptor beta and related muscle remodelling signals [7]. For a ten-week supplement trial using a gold-standard endpoint, that is a genuine finding.

What it did not find

Usually omitted. There was no significant change in body weight, body composition, liver fat, blood pressure, plasma lipids or markers of inflammation. Notably, muscle NAD⁺ content did not measurably increase — meaning the mechanism behind the insulin sensitivity result is not fully explained [7].

The published exchange

The trial drew criticism in print. Charles Brenner noted a baseline imbalance in liver fat between groups — 6.3 ± 1.2% in the NMN arm against 14.8 ± 2.0% in placebo (P = 0.003) — and argued that since liver fat clearance is itself a target, this "was not an effectively randomized trial" [8]. The authors responded that muscle insulin sensitivity, the primary endpoint, was equivalent at baseline in both groups. Both exchanges appeared in Science in 2021 and are worth knowing when weighing this evidence.

Crucially: this trial studied metabolic function in postmenopausal women. It did not measure hot flushes, night sweats, mood, sleep, brain fog, bone density or libido.

Trials in older adults that are indirectly relevant

Sleep and physical function

A 2024 randomised, double-blind, placebo-controlled trial in GeroScience gave 250 mg/day to 60 older adults for 12 weeks. Blood NAD rose, four-metre walking speed was maintained where placebo declined, and sleep quality scores improved. Its primary outcome — a stepping test — showed no significant difference from placebo at either 4 or 12 weeks [9]. Participants were older adults of both sexes, not menopausal women specifically.

Dose-response

A multicentre dose-ranging trial in 80 healthy adults aged 40–65 compared placebo with 300 mg, 600 mg and 900 mg over 60 days. Blood NAD rose significantly at every dose, highest at 600 mg and 900 mg. Six-minute walk distance improved, and no safety signals emerged [10].

What systematic reviews conclude

This is where enthusiasm should meet caution, and it is the most important passage in this article.

A 2024 systematic review with meta-analysis in Critical Reviews in Food Science and Nutrition screened 4,049 records and pooled 12 studies with 513 participants. It found a significant effect of NMN in elevating blood NAD levels — but that most clinically relevant outcomes, including fasting glucose, triglycerides, total cholesterol, LDL-C and HDL-C, were not significantly different from control [11].

A separate systematic review of ten randomised trials found some improvements in physical performance measures alongside a reassuring safety profile [12], and a 2023 review in Advances in Nutrition summarised the human safety and anti-ageing data to date [13].

The pattern across all of these is consistent: NMN reliably does the biochemical thing it is supposed to do, and only sometimes produces a measurable functional change. Our article on whether NMN is a scam works through this gap, and longevity supplements that don't work applies the same lens elsewhere.

Claims that outrun the evidence

Hot flushes and night sweats

No randomised controlled trial has tested NMN against vasomotor symptoms. Not one. Any claim that NMN reduces hot flushes is an extrapolation, not a finding.

Hormone balance and oestrogen

There is no human evidence that NMN raises oestrogen, alters FSH or LH, or changes menstrual patterns in perimenopause. Some sites claim NMN makes oestrogen receptors "more receptive" via sirtuins; that is a mechanistic hypothesis from cell biology, not a clinical result.

Fertility and ovarian ageing

This traces to a genuinely notable 2020 paper in Cell Reports. Bertoldo and colleagues showed oocyte NAD⁺ falls with age in mice, and that NMN in drinking water restored spindle assembly, improved ovulation rates and enhanced fertility in aged females [14].

It is important research. It is also entirely in mice, at doses not comparable to human supplementation, and concerns fertility in reproductively ageing animals — not menopausal symptom relief in women. Menopause occurs when the follicle pool is effectively exhausted; no supplement creates new eggs or reverses that.

Bone density

Postmenopausal bone loss is driven primarily by oestrogen withdrawal. There are no human trials of NMN and bone mineral density. Vitamin D, calcium, resistance training and, where appropriate, HRT or bone-specific medication have actual evidence here [5].

Skin and hair

NAD⁺ declines have been measured in human skin [1], which makes the tissue a reasonable research target, but skin outcome trials with NMN in menopausal women are lacking. See supplements for skin ageing and astaxanthin vs collagen for ingredients with more direct dermatological evidence.

Evidence summary at a glance

NMN is not a substitute for HRT

This matters enough to state plainly. NICE NG23 advises offering HRT for vasomotor symptoms associated with menopause. The guideline also recommends a choice of vaginal oestrogen — cream, gel, tablet, pessary or ring — for genitourinary symptoms including for women already on systemic HRT; recommends cognitive behavioural therapy, with 2024 evidence showing it can reduce the frequency and severity of hot flushes and night sweats; and recommends fezolinetant as an option for moderate to severe vasomotor symptoms where HRT is unsuitable [5].

NICE also advises clinicians to explain that the efficacy and safety of unregulated preparations are unknown. A food supplement, however well formulated, sits in that category.

For balance: the British Menopause Society published a response to the 2024 update setting out limitations it believes should be considered when applying the guideline, particularly around how risks were presented [15]. That is a live professional debate about how to use HRT well — not an argument for using a supplement instead.

Safety, tolerability and who should avoid it

What the trials report

Across randomised trials at doses from 150 mg to 1,250 mg daily and durations up to 12 weeks, NMN has been well tolerated with no serious adverse events attributed to it [13]. A Japanese single-dose study found doses up to 500 mg safe in healthy men, with no significant changes in heart rate, blood pressure, oxygen saturation or body temperature [16].

Mild, self-limiting effects occasionally reported include nausea, loose stools, flushing, headache and disrupted sleep if taken late in the day. See whether you can take too much NMN.

The genuine limitation

Almost every human trial has run for 12 weeks or less. Nobody has published multi-year safety data in humans. A 2022 review in Journal of Advanced Research set out both the promises and the outstanding safety questions [17], including unresolved theoretical concerns about NAD⁺ availability and tumour metabolism.

Who should not take NMN

• Anyone pregnant, breastfeeding or who could become pregnant — the EFSA assessment explicitly excludes pregnant and lactating women [19], and pregnancy remains possible in perimenopause
• Anyone with a current or past cancer diagnosis, without oncologist input
• Anyone on medication for diabetes, given the insulin sensitivity signal and hypoglycaemia risk
• Anyone under 18
• Anyone with significant liver or kidney impairment, without medical advice

If you already take HRT, no interaction has been reported — but no study has formally tested the combination, so tell your prescriber what you are taking. See also can you take supplements together?

Is NMN legal in the UK?

Yes, but the regulatory picture is still moving, and two different jurisdictions are routinely confused.

Great Britain

NMN is classified as a novel food in Great Britain, meaning it was not widely consumed before 15 May 1997 and requires authorisation. An application for β-nicotinamide mononucleotide is registered with the Food Standards Agency and under assessment [18]. Products remain on sale during that process.

European Union

EFSA's Panel on Nutrition, Novel Foods and Food Allergens published a safety opinion on chemically synthesised β-NMN, assessing its use in food supplements as a source of niacin at up to 300 mg per day for adults, excluding pregnant and lactating women, and concluding that its identity, production process, composition and specifications do not raise safety concerns [19]. That is a step in the EU authorisation process and does not itself govern GB.

United States

In two letters dated 29 September 2025, the FDA reversed its 2022 position and concluded that NMN is not excluded from the definition of a dietary supplement. The reversal rested on its reinterpretation of the "race to market" provision: the agency accepted evidence that NMN was marketed as a dietary supplement in the US before it was authorised for investigation as a drug [20]. In December 2025 it referenced that conclusion in letters reinstating new dietary ingredient status for NMN suppliers [20].

For UK buyers, see buying NMN in the UK, whether Boots sells NMN, NMN at Holland & Barrett and NMN on Amazon UK.

Dose, timing and stacking

Dose

Human trials have used 150–1,250 mg daily. The two most defensible anchors are 250 mg — the dose used in the postmenopausal women's trial [7] and in the sleep and walking-speed trial [9] — and 300 mg, the level EFSA assessed [19]. Higher doses raise blood NAD⁺ further [10], but higher NAD⁺ has not translated into proportionally better outcomes in the published data [11].

A reasonable starting point for most women in midlife is 250–500 mg daily. See NMN dosage by age.

Timing

Most trials dosed in the morning. Some people report NMN taken in the evening interferes with sleep, which is worth avoiding if disturbed sleep is already a menopausal complaint. See when to take NMN and NMN with food.

Methylation and TMG

NAD⁺ metabolism produces nicotinamide, which is cleared via methylation. In theory, high-dose NMN could increase demand for methyl donors, which is why trimethylglycine is commonly recommended alongside it. The evidence that this is necessary at typical doses is limited rather than settled — see do I need TMG with NMN, TMG vs methylfolate and buying TMG in the UK.

Common stack partners

For women in midlife the most commonly paired compounds are creatine, vitamin D and omega-3. See creatine for longevity, NMN vs creatine, the NMN, TMG and resveratrol stack — noting the resveratrol evidence is weaker than marketed, per does resveratrol work? — and the minimal supplement stack. Sequencing is covered in how to start longevity supplements and the supplement timing chart.

How to judge product quality

• A batch-specific certificate of analysis you can request and read — see supplement certificates of analysis
• Genuine independent lab verification, not a manufacturer's own paperwork — see third-party tested supplements
• Purity stated at ≥98% β-NMN, with the alpha anomer specified as minimal
• Sensible excipients — see supplement fillers
• Price per effective milligram, not per capsule — see cheapest NMN in the UK and longevity stack cost in the UK

Sublingual and liposomal formats are marketed as superior, though comparative human bioavailability data remains sparse. We assess the claims in sublingual NMN and liposomal NMN.

What has stronger evidence for menopause

If your priority is symptom relief rather than cellular biology, the hierarchy is worth stating clearly:

• HRT — offered for vasomotor symptoms per NICE NG23 [5]
• Vaginal oestrogen — for genitourinary symptoms, with new 2024 recommendations [5]
• Cognitive behavioural therapy — 2024 evidence that it reduces frequency and severity of hot flushes and night sweats [5]
• Fezolinetant — where HRT is unsuitable [5]
• Resistance training — the most reliable intervention for preserving muscle and bone through midlife; see zone 2 training for longevity
• Vitamin D and calcium — established for bone health after menopause

NMN belongs after these, not instead of them. For prioritising more broadly, see how to build a longevity stack and magnesium threonate vs glycinate if sleep is the issue.

A realistic 12-week trial plan

If you decide to try NMN, run it as a small experiment rather than an act of faith.

On realistic timelines, see how long supplements take to work. A single panel such as the Full Body MOT Health Check or Welzo Well-Human advanced blood test gives you comparable before-and-after bloods; thyroid and ferritin are worth including, since both can mimic menopausal symptoms.

Some women also track biological age markers. Treat those cautiously — whole-blood NAD⁺ in particular has been reported not to vary with age [22], and it is what most commercial NAD⁺ tests measure. See how to lower your biological age.

When to speak to a doctor

Speak to your GP if menopausal symptoms are affecting your quality of life. Effective treatments exist and you do not have to endure it [5].

Speak to your GP or pharmacist before starting NMN if you take prescription medication, have a diagnosed condition including kidney or liver disease, have a personal history of cancer, or are pregnant, breastfeeding or could become pregnant.

Seek prompt medical assessment — rather than adjusting a supplement — for any bleeding after the menopause, unscheduled bleeding while taking HRT, a new breast lump or breast change, persistent pelvic pain or bloating, unintended weight loss, or persistent unexplained fatigue. Postmenopausal bleeding always warrants assessment. Never stop or reduce prescribed medication, including HRT, in order to try a supplement.

Frequently asked questions

Does NMN help with menopause symptoms?

There is no clinical trial evidence that NMN reduces hot flushes, night sweats, mood changes or brain fog. One randomised trial in postmenopausal women found improved muscle insulin sensitivity, which relates to metabolic health rather than symptom relief [7]. NMN should not be expected to function as a menopause treatment.

Can NMN increase oestrogen levels?

No. NMN is not a hormone, does not act on oestrogen receptors, and no human study has shown it raises oestrogen. Claims that it "balances hormones" during menopause are unsupported by clinical data.

What dose of NMN should a menopausal woman take?

The 2021 trial in postmenopausal women used 250 mg daily for ten weeks [7]. EFSA assessed β-NMN at up to 300 mg per day for adults, excluding pregnant and lactating women [19]. A starting range of 250–500 mg daily reflects the trial evidence; higher doses raise blood NAD⁺ further without proven additional benefit [10,11].

Is NMN safe to take during perimenopause?

Randomised trials up to 1,250 mg daily for up to 12 weeks have reported good tolerability with no serious adverse events [13]. Long-term safety data beyond 12 weeks does not exist [17]. It should be avoided in pregnancy and breastfeeding — relevant in perimenopause, when pregnancy is still possible — and by anyone with a cancer history or on diabetes medication without medical advice.

Can I take NMN alongside HRT?

No interaction between NMN and hormone replacement therapy has been reported, but no study has formally tested the combination. Tell your prescriber about any supplement you take so your care is coordinated. NMN is not a replacement for HRT [5].

Does NMN help with menopausal weight gain?

The trial in postmenopausal women found no significant change in body weight or body composition after ten weeks [7]. A meta-analysis of twelve trials also found no significant effect on most metabolic outcomes [11]. NMN should not be purchased as a weight management product.

Will NMN improve fertility or delay menopause?

Mouse research published in Cell Reports showed NMN improved oocyte quality and fertility in aged female mice [14]. This has not been replicated in humans, and no evidence exists that NMN delays the onset of menopause. Menopause occurs when the follicle pool is exhausted; no supplement creates new eggs.

Does NMN help with menopausal fatigue?

One randomised trial in older adults found improved sleep quality with 250 mg daily over 12 weeks, though its primary outcome showed no difference from placebo [9]. Those participants were not specifically menopausal women, so the finding is indirect and preliminary rather than established.

How long does NMN take to work?

Blood NAD⁺ rises within days to weeks [10]. Functional changes, where they occur at all, have generally been measured at 8–12 weeks in trials. If you have noticed nothing after 12 weeks at a consistent dose, further time is unlikely to change the outcome.

Is NMN legal to buy in the UK in 2026?

Yes. NMN is available in the UK and is classified as a novel food under assessment by the Food Standards Agency [18]. EFSA has published a safety opinion on β-NMN at up to 300 mg daily for adults [19], and the US FDA reversed its exclusion of NMN from the dietary supplement definition in September 2025 [20] — though that is a US decision with no direct bearing on UK availability, and legal analysts note it could face challenge [21]. Check current FSA guidance for the latest position.

References

1. Massudi H, Grant R, Braidy N, et al. Age-associated changes in oxidative stress and NAD⁺ metabolism in human tissue. PLoS ONE. 2012;7(7):e42357. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0042357
2. Chini CCS, Cordeiro HS, Tran NLK, Chini EN. NAD metabolism: role in senescence regulation and aging. Aging Cell. 2024;23(1):e13920. https://onlinelibrary.wiley.com/doi/10.1111/acel.13920
3. Peluso A, Damgaard MV, Mori MAS, Treebak JT. Age-dependent decline of NAD⁺ — universal truth or confounded consensus? Nutrients. 2022;14(1):101. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8747183
4. Vinten KT, Trętowicz MM, Coskun E, et al. NAD⁺ precursor supplementation in human ageing: clinical evidence and challenges. Nature Metabolism. 2025;7(10):1974–1990. https://www.nature.com/articles/s42255-025-01387-7
5. National Institute for Health and Care Excellence. Menopause: identification and management (NG23). Updated November 2024; amended April 2026. https://www.nice.org.uk/guidance/ng23/chapter/recommendations
6. El Khoudary SR, Aggarwal B, Beckie TM, et al. Menopause transition and cardiovascular disease risk: a scientific statement from the American Heart Association. Circulation. 2020;142(25):e506–e532. https://pubmed.ncbi.nlm.nih.gov/33251828/
7. 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
8. Brenner C. Comment on "Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women". Science. 2021;373:eabj1696. https://www.science.org/doi/10.1126/science.abj1696
9. Morifuji M, Higashi S, Ebihara S, Nagata M. Ingestion of β-nicotinamide mononucleotide increased blood NAD levels, maintained walking speed, and improved sleep quality in older adults. GeroScience. 2024;46(5):4671–4688. https://pmc.ncbi.nlm.nih.gov/articles/PMC11336149
10. Yi L, Maier AB, Tao R, et al. The efficacy and safety of β-nicotinamide mononucleotide supplementation in healthy middle-aged adults: a randomised, dose-dependent clinical trial. GeroScience. 2023;45(1):29–43. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9735188
11. Efficacy of oral nicotinamide mononucleotide supplementation on glucose and lipid metabolism for adults: a systematic review with meta-analysis on randomised controlled trials. Critical Reviews in Food Science and Nutrition. 2024. https://www.tandfonline.com/doi/full/10.1080/10408398.2024.2387324
12. Improved physical performance parameters in patients taking nicotinamide mononucleotide: a systematic review of randomised controlled trials. Cureus. 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11365583
13. Song Q, Zhou X, Xu K, et al. The safety and antiaging effects of nicotinamide mononucleotide in human clinical trials: an update. Advances in Nutrition. 2023;14(6):1416–1435. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10721522
14. Bertoldo MJ, Listijono DR, Ho WHJ, et al. NAD⁺ repletion rescues female fertility during reproductive aging. Cell Reports. 2020;30(6):1670–1681. https://www.sciencedirect.com/science/article/pii/S2211124720300838
15. British Menopause Society. Response to the updated NICE guideline on menopause (NG23). https://thebms.org.uk/publications/nice-guideline/
16. Irie J, Inagaki E, Fujita M, et al. Effect of oral administration of nicotinamide mononucleotide on clinical parameters and nicotinamide metabolite levels in healthy Japanese men. Endocrine Journal. 2020;67(2):153–160. https://www.jstage.jst.go.jp/article/endocrj/67/2/67_EJ19-0313/_article
17. Nadeeshani H, Li J, Ying T, Zhang B, Lu J. Nicotinamide mononucleotide (NMN) as an anti-aging health product — promises and safety concerns. Journal of Advanced Research. 2022;37:267–278. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9039735
18. Food Standards Agency. Register of regulated product applications: β-nicotinamide mononucleotide (RP-2116). https://data.food.gov.uk/regulated-product-applications/products-list/RP-2116
19. EFSA Panel on Nutrition, Novel Foods and Food Allergens. Safety of beta-nicotinamide mononucleotide (β-NMN) pursuant to Regulation (EU) 2015/2283. EFSA Journal. 2026;24(5):e10007. https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2026.10007
20. NutraIngredients. FDA declares NMN lawful in dietary supplements, 30 September 2025; and FDA reinstates NDI status of NMN with new letters to ingredient players, 9 December 2025. https://www.nutraingredients.com/Article/2025/09/30/fda-declares-nmn-lawful-in-dietary-supplements/
21. Venable LLP. FDA declares nicotinamide mononucleotide is a dietary supplement. October 2025 — legal analysis noting the determination reflects current agency thinking and may face judicial or state-law challenge. https://www.venable.com/insights/publications/2025/10/fda-declares-nicotinamide-mononucleotide-is
22. Human whole-blood NAD⁺ levels do not vary with age or lifestyle interventions. Nature Metabolism. 2026. https://www.nature.com/articles/s42255-026-01537-5

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