NMN Review 2026: Evidence Grade, Doses and Side Effects

NMN does one thing reliably: it raises blood NAD. Every claim built on top of that, from longer life to sharper memory to better blood sugar, is either untested in people or has already failed its trials.

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Across 12 randomized trials with 513 participants, oral NMN significantly raised blood NAD levels while fasting glucose and lipids did not differ from control, and the review authors wrote that “an exaggeration of NMN benefits may exist in the field” (PMID 39116016). That single sentence is the NMN story in miniature. The molecule is a precursor to nicotinamide adenine dinucleotide, a coenzyme that declines with age and sits at the center of cellular energy metabolism, DNA repair and sirtuin signaling. The supplement industry has turned that biochemistry into a longevity product. The human record cited here, from single trials to six meta-analyses, supports the biomarker and almost nothing else. This review grades ten marketed claims against that record using the Healthcare Discovery HYPE Index and names, for each one, exactly what the evidence does not cover.

The HYPE Index verdict

The HYPE Index measures the distance between the strongest public claim and the calibration appropriate to its stage of evidence, from 0 (fully calibrated) to 100 (maximum gap), with scores above 60 flagged as a Significant Evidence Gap; the method is described at Healthcare Discovery’s HYPE Index methodology.

Claim	Evidence grade	HYPE composite	Verdict
Improves egg quality and fertility	Insufficient	80, Significant Evidence Gap	A 2025 systematic review found 7 animal studies of NMN and oocyte quality and no human NMN fertility trial (PMID 41160202).
Protects the brain and sharpens cognition	Insufficient	77, Significant Evidence Gap	A 2024 systematic review found 3 preclinical NMN studies and zero human clinical trials of NMN in Alzheimer’s disease (PMID 39422945).
Slows aging and extends healthspan	Insufficient	77, Significant Evidence Gap	A 2026 systematic review of 113 studies found NMN and NR reliably raised NAD metabolites but produced heterogeneous and often null healthspan outcomes, with no human trial of any aging endpoint (PMID 41655607).
Improves insulin sensitivity and lowers blood sugar	Contradicted	64, Significant Evidence Gap	In a 2024 meta-analysis of 8 RCTs (n=342), NMN at 250 to 2,000 mg per day for 14 days to 12 weeks had no significant effect on fasting glucose, insulin, HbA1c or HOMA-IR (PMID 39531138).
Supports weight loss and metabolic health	Insufficient	62, Significant Evidence Gap	In a 28-day RCT of 30 overweight adults, 2,000 mg per day of a pharmaceutical-grade NMN reduced body weight by 1.9 kg (95% CI -3.3 to -0.5), but a 2026 meta-analysis of 15 RCTs found no effect on body weight or BMI (PMID 36740954; PMID 42514320).
Boosts endurance, strength and physical performance	Preliminary	56, Mixed calibration	In a 2025 meta-analysis of 9 RCTs (n=412), NMN improved gait speed by a standardized mean difference of 0.34 (95% CI 0.03 to 0.66), while a separate 2025 meta-analysis found no effect on handgrip strength or muscle mass in adults over 60 (PMID 39185644; PMID 40275690).
Improves sleep quality and reduces fatigue	Preliminary	53, Mixed calibration	In a 12-week RCT of 60 older adults, NMN at 250 mg per day missed its primary stepping-test endpoint but improved Pittsburgh Sleep Quality Index scores as a secondary outcome (PMID 38789831).
Lowers blood pressure and supports heart health	Preliminary	41, Mixed calibration	In a 2026 meta-analysis of 10 RCTs (n=349), NMN lowered resting diastolic blood pressure by 2.15 mmHg (95% CI -3.68 to -0.61) versus placebo with no overall change in systolic pressure (PMID 41901064).
Is safe and well tolerated at doses up to 2,000 mg per day	Moderate	33, Largely calibrated	In a 2026 meta-analysis of 15 RCTs, oral NMN at 250 to 2,000 mg per day for 14 days to 24 weeks did not increase overall or serious adverse events or raise ALT or AST (PMID 42514320).
Raises blood NAD+ levels	Strong	31, Largely calibrated	In a 2024 meta-analysis of 12 RCTs (n=513), oral NMN significantly raised blood NAD levels while fasting glucose and lipids did not differ from control (PMID 39116016).

The chain of hype for the top-scoring claim runs from mouse to clinic without passing through a trial. Seven animal studies showed NMN improved mitochondrial function in aged oocytes (PMID 41160202). The marketed claim that NMN improves egg quality applies that rodent data to women trying to conceive. No human has been enrolled in a controlled NMN fertility trial, so the drift happened at the first link, where a preclinical finding became a consumer claim. The longevity claim follows the same path with one extra step: a 60-day biomarker shift in 80 healthy adults, in a trial co-sponsored by the companies that made the NMN tested (PMID 36482258), becomes “anti-aging,” an outcome no trial has measured.

What the research shows

Raising blood NAD

In a 2024 meta-analysis of 12 RCTs (n=513), oral NMN significantly raised blood NAD levels while fasting glucose and lipids did not differ from control (PMID 39116016). This is the one claim with strong support. The largest dose-ranging trial, 80 healthy middle-aged adults given 300, 600 or 900 mg once daily for 60 days, found blood NAD rose at days 30 and 60 at every dose, highest at 600 and 900 mg (PMID 36482258). A 2026 open-label trial of 65 healthy adults found 14 days of NR or NMN, but not plain nicotinamide, comparably raised circulating NAD, and ex vivo work suggested gut microbes convert both to nicotinic acid first (PMID 41540253). What we do not know: whether a higher blood NAD level translates into any clinical benefit, how large the rise is at 250 mg per day, the dose most trials used (abstracts rarely report the magnitude), and whether it persists beyond 24 weeks. Risk of bias was rated as some concerns in 7 of the 12 pooled trials and high in 5.

Safety and tolerability

In a 2026 meta-analysis of 15 RCTs, oral NMN at 250 to 2,000 mg per day for 14 days to 24 weeks did not increase overall or serious adverse events or raise ALT or AST (PMID 42514320). A dedicated safety trial in 31 healthy adults aged 20 to 65 found 1,250 mg once daily for 4 weeks produced no changes beyond physiological variation in blood, urine or body composition (PMID 36002548). What we do not know: safety beyond 24 weeks, safety in people with a cancer history (a 2020 review of 147 articles raised theoretical concerns about tumorigenesis and senescence from chronic NAD elevation, PMID 31917996), and interactions with chemotherapy or sirtuin-targeting drugs. Most trials enrolled healthy or mildly metabolically impaired adults, and most had authors from companies that make NMN (see who ran the trials, below).

Blood pressure

In a 2026 meta-analysis of 10 RCTs (n=349), NMN lowered resting diastolic blood pressure by 2.15 mmHg (95% CI -3.68 to -0.61) versus placebo with no overall change in systolic pressure (PMID 41901064). Adults aged 60 and older showed a 3.94 mmHg systolic reduction (95% CI -7.06 to -0.82) in a subgroup analysis. The 28-day MIB-626 trial produced a larger diastolic drop of 7.01 mmHg (95% CI -13.44 to -0.59) at 2,000 mg per day in 30 overweight adults (PMID 36740954). What we do not know: whether a 2 mmHg change persists beyond 24 weeks or alters any cardiovascular event. Arterial stiffness, measured as pulse wave velocity, tended to fall without a significant between-group difference in a 12-week trial of 36 adults at 250 mg per day (PMID 36797393).

Sleep and fatigue

In a 12-week RCT of 60 older adults, NMN at 250 mg per day missed its primary stepping-test endpoint but improved Pittsburgh Sleep Quality Index scores as a secondary outcome (PMID 38789831). A four-arm trial of 108 older Japanese adults comparing morning and afternoon dosing found within-group improvements in drowsiness and sit-to-stand performance, largest in the afternoon NMN group (d=0.64 for drowsiness), but placebo groups improved too and the abstract does not report a clear NMN-versus-placebo difference (PMID 35215405). What we do not know: any objective sleep measure, results in people with diagnosed insomnia, and whether the 400-patient, 60-day trial of 320 mg per day registered as ChiCTR2200058001 confirms the signal (PMID 37202819). That trial is still a protocol.

Endurance, strength and physical performance

In a 2025 meta-analysis of 9 RCTs (n=412), NMN improved gait speed by a standardized mean difference of 0.34 (95% CI 0.03 to 0.66), while a separate 2025 meta-analysis found no effect on handgrip strength or muscle mass in adults over 60 (PMID 39185644; PMID 40275690). The second analysis reported a skeletal muscle index difference of -0.42 (95% CI -0.99 to 0.14), handgrip 0.61 kg (95% CI -0.89 to 2.10) and gait speed -0.01 m/s (95% CI -0.08 to 0.06), all null. In 48 amateur runners, 6 weeks at 600 or 1,200 mg per day improved oxygen uptake and power at the ventilatory thresholds, but VO2max and peak power did not change in any group (PMID 34238308). The most cautionary result comes from 11 non-athletic men: 7 days at 1,200 mg per day abolished the 171 percent increase in muscle mitochondrial content seen 24 hours after exercise with placebo (PMID 41705654). What we do not know: whether the submaximal gains persist beyond 6 weeks, whether NMN blunts training adaptation in trained adults, and whether any trial shows strength gains versus placebo (none does).

Weight loss and metabolic health

In a 28-day RCT of 30 overweight adults, 2,000 mg per day of a pharmaceutical-grade NMN reduced body weight by 1.9 kg (95% CI -3.3 to -0.5), but a 2026 meta-analysis of 15 RCTs found no effect on body weight or BMI (PMID 36740954; PMID 42514320). The positive trial used MIB-626, a microcrystalline formulation at eight times the 250 mg per day used in most trials, tested by a team that included an author from its developer, Metro International Biotech, with 2:1 randomization and no prespecified primary efficacy endpoint. It also reported total cholesterol down 26.89 mg/dL and LDL down 18.73 mg/dL, with no change in insulin sensitivity, liver fat or abdominal fat. What we do not know: whether any weight effect exists at 250 to 500 mg per day, whether it lasts beyond 4 weeks, and what role the proprietary formulation plays.

Insulin sensitivity and blood sugar

In a 2024 meta-analysis of 8 RCTs (n=342), NMN at 250 to 2,000 mg per day for 14 days to 12 weeks had no significant effect on fasting glucose, insulin, HbA1c or HOMA-IR (PMID 39531138). Two further meta-analyses agree: the 12-trial analysis found no glucose or lipid change (PMID 39116016), and the 15-trial safety analysis found no change in fasting glucose, HbA1c or lipids, with only a non-significant downward trend in HOMA-IR (PMID 42514320). The claim rests almost entirely on one 10-week clamp study in overweight postmenopausal women with prediabetes, in which 250 mg per day raised muscle insulin sensitivity by about 25 percent in the 13 women on NMN while fasting glucose, insulin and liver fat did not change in either group, according to the full report (PMID 33888596). Healthcare Discovery grades this claim contradicted because controlled trials consistently show no effect where benefit is sold. What we do not know: whether people with established type 2 diabetes respond differently over longer than 12 weeks.

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Slowing aging and extending healthspan

A 2026 systematic review of 113 studies found NMN and NR reliably raised NAD metabolites but produced heterogeneous and often null healthspan outcomes, with no human trial of any aging endpoint (PMID 41655607). The only “biological age” result in the literature comes from the 80-person dose-ranging trial, where a proprietary blood-based algorithm (Aging.Ai 3.0) held steady in the NMN groups while rising with placebo over 60 days (PMID 36482258). A 2020 review of 147 articles, 113 of them preclinical, reported mostly favorable effects in age-related disorder models alongside potential risks of toxic metabolite accumulation, tumorigenesis and cellular senescence (PMID 31917996). What we do not know: any effect on mortality, disease incidence, frailty or a validated aging clock; safety beyond 24 weeks; and whether chronic NAD elevation carries the risks preclinical reviews have raised. The cautionary precedent is antioxidant supplements, which also looked promising at the biomarker stage: a 2012 Cochrane review of 78 randomized trials with 296,707 participants found no mortality benefit overall and a small increase in mortality in the 56 trials at low risk of bias (RR 1.04, 95% CI 1.01 to 1.07) (PMID 22419320).

Brain protection and cognition

A 2024 systematic review found 3 preclinical NMN studies and zero human clinical trials of NMN in Alzheimer’s disease (PMID 39422945). The two human trials in that review used nicotinamide riboside, a different precursor. A 2026 narrative review of Parkinson’s models proposes mitochondrial and autophagy mechanisms without any human NMN outcome (PMID 42877680). What we do not know: everything at the human level. No randomized trial has measured memory, attention, mood or a neurodegeneration biomarker after NMN.

Egg quality and fertility

A 2025 systematic review found 7 animal studies of NMN and oocyte quality and no human NMN fertility trial (PMID 41160202). The human component of that review was descriptive sequencing of 46 oocytes with no NMN intervention. What we do not know: oocyte yield, embryo quality, pregnancy rate or live birth rate after NMN in any controlled human study. This is the highest-scoring gap in the NMN market.

Doses used in studies

These are doses reported by the named sources, not recommendations.

Source	Dose reported	Form	Context
PMID 36482258	300, 600 or 900 mg once daily for 60 days	Oral NMN	Multicenter dose-ranging RCT in healthy middle-aged adults, mean age about 49
PMID 36797393	125 mg twice daily, 250 mg per day, for 12 weeks	Oral NMN	RCT in healthy middle-aged adults
PMID 36443648	250 mg once daily for 24 weeks	Oral NMN	RCT in men aged 65 and older with diabetes and reduced grip strength or walking speed
PMID 35215405	250 mg once daily, morning or afternoon, for 12 weeks	Oral NMN	RCT in older Japanese adults comparing time of dosing
PMID 36740954	1,000 mg twice daily, 2,000 mg per day, for 28 days	MIB-626 microcrystalline beta-NMN	Placebo-controlled RCT in overweight or obese adults aged 45 and older
PMID 36002548	1,250 mg once daily for up to 4 weeks	Oral beta-NMN	Safety trial in healthy adults aged 20 to 65
PMID 41705654	1,200 mg per day for 7 days	Oral NMN	Crossover trial in non-athletic young men, mean age about 23
PMID 39531138	250 to 2,000 mg per day for 14 days to 12 weeks	Oral NMN, various products	Meta-analysis of 8 RCTs in mainly non-diabetic middle-aged and older adults

Forms and quality

Nearly every human trial used plain oral beta-NMN powder in capsules. The one formulation studied head to head with a pharmacokinetic design is MIB-626, a microcrystalline beta-NMN from Metro International Biotech. In 32 overweight or obese adults aged 55 to 80, 14 days of MIB-626 raised blood NMN exposure 1.7-fold at 1,000 mg once daily and 3.7-fold at twice daily, with dose-related increases in blood NAD (PMID 35182418). That proprietary formulation is not the plain powder most trials used, so its results do not transfer automatically to other products. Sublingual NMN, marketed for superior absorption, was tested against oral NMN in 14 healthy men: the sublingual route produced higher 60-minute levels of the terminal catabolites 2PY and 4PY but no difference in blood NMN, nicotinamide or NAD itself (PMID 42304075), so the bioavailability claim is not supported by the primary NAD measure. The 2026 gut-conversion trial complicates the “direct precursor” story further, since both NR and NMN appeared to work by being converted to nicotinic acid by gut bacteria (PMID 41540253). For a reader comparing products, the relevant quality markers are third-party testing for identity and purity, a stated beta-NMN content per capsule, and a certificate of analysis from an independent lab. Healthcare Discovery’s companion page NMN vs Nicotinamide Riboside compares the two precursors directly.

Interactions and who the trials excluded

Interacts with	Type	Severity	Mechanism and evidence
Niacin, nicotinamide, nicotinamide riboside and other NAD precursors	Supplement	Minor	All feed the same NAD pool; NMN alone raised the methylated nicotinamide metabolites 2PY and 4PY dose-dependently in 10 healthy men (PMID 31685720), and no trial has tested whether stacking adds benefit
Blood NAD and nicotinamide metabolite measurements	Lab test	Minor	Oral NMN raises blood NAD (PMID 39116016) and plasma 2PY and 4PY (PMID 31685720), so recent intake confounds these assays
Insulin and glucose-lowering drugs (metformin, sulfonylureas, GLP-1 agonists)	Drug	Theoretical	NMN improved muscle insulin sensitivity by about 25 percent in prediabetic women (PMID 33888596); no trial in medicated diabetics; no hypoglycemia reported
NAMPT inhibitors and NAD-depleting anticancer drugs in development	Drug	Theoretical	Mechanistic reasoning only: NMN enters NAD synthesis downstream of NAMPT, the enzyme these drugs block, so it could in principle offset them; no published study tests this with NMN
Active cancer or cancer treatment	Condition	Theoretical	A 2020 benefit and risk review flagged tumorigenesis as a potential risk of chronic NAD elevation (PMID 31917996); NMN trials excluded people with cancer
Liver disease	Condition	Theoretical	NMN appears to be processed largely by gut bacteria before it reaches the blood (PMID 41540253); no trial enrolled impaired liver function; pooled trials up to 24 weeks showed no rise in ALT or AST (PMID 42514320)
Methyl donor status (folate, B12, TMG, choline)	Supplement	Theoretical	Mechanistic reasoning only: NMN raises methylated nicotinamide metabolites (PMID 31685720), and methylation draws on the body’s methyl donors; no study has shown a clinical effect on methyl donor status with NMN
Sirtuin activators such as resveratrol and pterostilbene	Supplement	Theoretical	Sirtuins use NAD as a cosubstrate, and cell studies found low-dose NAD precursors, NMN included, raised Sirt1 activity when combined with leucine (PMID 32758058, a study whose authors include NuSirt Biopharma staff); no human trial of NMN with resveratrol or pterostilbene
Pregnancy and breastfeeding	Condition	Theoretical	No safety data; every published trial excluded pregnant and lactating women
Surgery and anesthesia	Condition	Theoretical	No data on bleeding, anesthesia or wound healing; no trial enrolled surgical patients
Children and adolescents	Condition	Theoretical	No safety or dosing data; every trial enrolled adults, most middle-aged or older

Beyond these rows, the exclusion criteria themselves define who the evidence covers. Trials enrolled healthy middle-aged adults, older Japanese adults, overweight or obese adults over 45, postmenopausal women with prediabetes, amateur runners and diabetic men over 65 with reduced grip strength or walking speed. No trial enrolled people under 20, people with cancer, pregnant women or people with liver or kidney disease.

Side effects reported in trials

The 15-trial 2026 meta-analysis found no increase in overall adverse events, serious adverse events, withdrawals due to adverse events, or ALT and AST at 250 to 2,000 mg per day for 14 days to 24 weeks (PMID 42514320). A 2025 meta-analysis of 9 RCTs reported a small decrease in ALT (SMD -0.29, 95% CI -0.55 to -0.03) (PMID 39185644). Individual trials at 250 mg per day for 12 to 24 weeks (PMID 38789831; PMID 36443648), 1,250 mg per day for 4 weeks (PMID 36002548) and 2,000 mg per day for 28 days (PMID 36740954) reported adverse events similar to placebo and no severe events. The one physiological signal that reads as a possible harm is the 7-day study in which 1,200 mg per day abolished the post-exercise rise in mitochondrial content (PMID 41705654), a mechanistic biopsy finding in 11 men that has not been replicated. A post hoc analysis of the 80-person trial found baseline blood NAD associated with slightly higher triglycerides, lower HDL and higher ALT and AST, associations too small and too correlational to interpret (PMID 41162813). No trial exceeds 24 weeks.

Who ran the trials

Most of the human NMN record comes from trials with authors who work for companies that make or develop NMN. The table lists what PubMed author affiliations and, where we could read it, the trial report show. Company involvement does not make a result wrong, and the meta-analyses above pool these trials with academic ones, but readers weighing a single positive trial should know who ran it.

Trial	What it found	Company tie
PMID 36482258 and post hoc PMID 41162813	Blood NAD, six-minute walk and biological age algorithm results in 80 adults	Co-sponsored by ABA Chemicals and Abinopharm, which made the NMN tested; authors from both
PMID 36740954 and PMID 35182418	MIB-626 weight, blood pressure and pharmacokinetic results	Author from Metro International Biotech, developer of MIB-626
PMID 38789831 and PMID 42304075	Sleep and walking results in older adults; sublingual versus oral pharmacokinetics	Authors from Meiji Holdings
PMID 35215405 and PMID 36002548	Morning versus afternoon dosing; 1,250 mg safety trial	Authors from Mitsubishi Corporation Life Sciences
PMID 36443648 and PMID 42082179	24-week trial in older diabetic men and its retinal sub-analysis	Authors from Teijin and NOMON
PMID 36797393	12-week arterial stiffness trial	Authors from DHC Corporation laboratories
PMID 41540253	Gut conversion of NR and NMN in 65 adults	Authors from Nestlé Health Science and Nestlé Research
PMID 31685720	Single-dose safety and metabolites in 10 men	Authors from Shionogi

The clamp study in prediabetic women (PMID 33888596), the runner trial (PMID 34238308) and the 7-day mitochondrial study (PMID 41705654) list only academic affiliations on PubMed. Affiliations are not a full disclosure, so a trial with academic affiliations can still have industry funding or consulting ties that only its conflict-of-interest statement would show.

How it fits the Five Pillars

NMN is sold as a shortcut to a biological state that the Five Pillars already reach. Under Movement, a 2023 meta-analysis of 5 studies found exercise training raised skeletal muscle NAMPT, the rate-limiting enzyme of NAD synthesis, by about 1.46-fold (Cohen’s d 0.81, 95% CI 0.55 to 1.07) (PMID 37954044), and the 7-day NMN study hints that the supplement may interfere with exactly that adaptation (PMID 41705654). Under Nutrition, the gut-conversion trial suggests that the body treats NMN much like dietary niacin from fish, poultry, legumes and whole grains (PMID 41540253), and the three null glycemic meta-analyses mean a capsule does not substitute for the blood sugar control that whole-food eating patterns deliver. Under Sleep, the only positive sleep signals were secondary questionnaire outcomes in older adults (PMID 38789831), far weaker than the evidence for consistent sleep timing and light exposure. No trial in this evidence set measured a Breathwork or Mindset outcome. The Four Villains of Health and Longevity framework places cardiovascular disease, cancer, neurodegeneration and metabolic dysfunction at the center; NMN has a 2 mmHg diastolic signal on the first, a theoretical concern on the second, no human data on the third and three null meta-analyses on the fourth.

What this means for you

The honest summary of this record is that NMN does what its label says in the narrowest sense, raising a blood biomarker, and does not yet do what its marketing implies. Short-term tolerability through 24 weeks looks good. Blood pressure moves by about 2 mmHg diastolic. Walking speed in older adults may improve slightly, while strength and muscle mass do not. Blood sugar, weight, cognition, fertility and aging itself are either untested or have failed. Anyone weighing a product priced on its longevity promise can hold it to the same standard Healthcare Discovery applies: name the human trial, the population, the duration and the outcome. For NMN, the outcome column is still mostly empty. Related Healthcare Discovery coverage includes The NAD+ Decline, The NAD+ Question and Spermidine and the Autophagy Switch, and the companion pages for this review answer the queries readers ask most: Does NMN slow aging, NMN side effects, Does NMN lower blood sugar, NMN for endurance and How long does NMN take to work.

New since our last review

This is the first edition of this review. Every citation was checked against PubMed on October 27, 2026, and the trial sponsors and author affiliations were added after that check.

Sources

PMID 39116016, 2024 meta-analysis of 12 RCTs (n=513), NAD raised, glucose and lipids unchanged
PMID 42514320, 2026 meta-analysis of 15 RCTs, safety and metabolic outcomes
PMID 39531138, 2024 meta-analysis of 8 RCTs (n=342), glycemic outcomes null
PMID 41901064, 2026 meta-analysis of 10 RCTs (n=349), blood pressure
PMID 39185644, 2025 meta-analysis of 9 RCTs (n=412), gait speed and ALT
PMID 40275690, 2025 meta-analysis, muscle outcomes in adults over 60
PMID 41655607, 2026 systematic review of 113 studies of NAD precursors
PMID 41160202, 2025 systematic review, NMN and oocyte quality
PMID 39422945, 2024 systematic review, NMN and NR in Alzheimer’s disease
PMID 31917996, 2020 systematic review of 147 articles on NAD precursors
PMID 36482258, 60-day dose-ranging RCT in 80 healthy adults
PMID 41162813, post hoc analysis of the 80-person trial
PMID 36740954, 28-day MIB-626 RCT in 30 overweight adults
PMID 35182418, 14-day MIB-626 pharmacokinetic RCT in 32 adults
PMID 36797393, 12-week RCT in 36 adults, arterial stiffness
PMID 36443648, 24-week RCT in 14 older diabetic men
PMID 42082179, retinal thickness sub-analysis of the 24-week trial
PMID 35215405, 12-week RCT in 108 older adults, morning versus afternoon dosing
PMID 38789831, 12-week RCT in 60 older adults, stepping test and sleep
PMID 37202819, protocol for a 400-patient insomnia RCT
PMID 34238308, 6-week RCT in 48 amateur runners
PMID 41705654, 7-day crossover in 11 non-athletic men, mitochondrial adaptation
PMID 41651893, single-dose RCT, interoception after exhaustive exercise
PMID 36002548, 4-week safety RCT in 31 healthy adults
PMID 33888596, 10-week clamp RCT in prediabetic postmenopausal women
PMID 41540253, 14-day trial in 65 adults, gut conversion of NR and NMN
PMID 42304075, sublingual versus oral NMN pharmacokinetics in 14 men
PMID 37954044, 2023 meta-analysis, exercise and muscle NAMPT
PMID 42877680, 2026 narrative review, NAD precursors in Parkinson’s models
PMID 32758058, leucine and resveratrol trial with preclinical NMN arms
PMID 31685720, single-dose safety and metabolite trial in 10 healthy men (Irie et al., Endocrine Journal 2020)
PMID 22419320, 2012 Cochrane review of 78 antioxidant supplement trials and mortality

Compiled by Healthcare Discovery from the cited PubMed studies. Every citation, author affiliation and trial sponsor named on this page was checked against PubMed on October 27, 2026, and the full reports of the trials that carry the most weight here were read where PubMed Central holds them (PMID 36482258, PMID 33888596, PMID 41160202, PMID 39531138, PMID 34238308 and PMID 41705654). How claims are scored: HYPE Index methodology.

Does NMN slow aging?

What are the side effects of NMN?

In a 2026 meta-analysis of 15 RCTs, oral NMN at 250 to 2,000 mg per day for 14 days to 24 weeks did not increase overall or serious adverse events or raise ALT or AST (PMID 42514320). No trial exceeds 24 weeks.

Does NMN lower blood sugar?

In a 2024 meta-analysis of 8 RCTs (n=342), NMN at 250 to 2,000 mg per day for 14 days to 12 weeks had no significant effect on fasting glucose, insulin, HbA1c or HOMA-IR (PMID 39531138).

Does NMN improve endurance and exercise performance?

How long does NMN take to work?

In 80 healthy adults, blood NAD rose by day 30 at 300 to 900 mg per day and remained elevated at day 60 (PMID 36482258), and 14 days of NMN raised circulating NAD in 65 adults (PMID 41540253), but metabolic markers did not change at 12 weeks in pooled trials (PMID 39531138).

Is NMN or nicotinamide riboside better?

In 65 healthy adults, 14 days of NR or NMN comparably raised circulating NAD and both appeared to be converted to nicotinic acid by gut bacteria (PMID 41540253); neither has a human trial with an aging outcome.

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NMN Review 2026: Evidence Grade, Best Form, Side Effects

The HYPE Index verdict