NMN (Nicotinamide Mononucleotide)
β-Nicotinamide mononucleotide
An NAD+ precursor that reliably raises blood NAD+, with hints of metabolic and physical-function benefit but no proven anti-aging effect.
Preliminary evidence
⏳Longevity
Evidence tier
Preliminary
Research weight
Citations
12 verified / 12
Classification
Longevity
❝
What the evidence says. Early or small human trials; promising but not yet conclusive.
What is NMN (Nicotinamide Mononucleotide)?
NMN (Nicotinamide Mononucleotide) (β-Nicotinamide mononucleotide) is a longevity supplement used for reliably and dose-dependently raises blood nad+ levels in humans, the biochemical rationale for its use. NutriDex grades the human evidence as Preliminary. NMN is a direct precursor to NAD+, a coenzyme central to cellular energy metabolism that declines with age, and it is heavily marketed for longevity and anti-aging. Human RCTs consistently show that oral NMN raises blood NAD+ levels in a dose-dependent manner, confirming it is bioavailable. However, downstream clinical benefits are far less certain: a 2024 meta-analysis of 8 RCTs (342 adults) found no significant effect on fasting glucose, insulin, HbA1c, HOMA-IR, or lipids, while a small prediabetes trial and some dose-ranging studies hint at gains in muscle insulin sensitivity and physical performance. Claims of extended lifespan or reversed aging in humans are unproven and rest largely on animal data. Short-term use up to 900 mg/day appears well tolerated, but long-term safety data are lacking. In the US its regulatory status has been turbulent: the FDA excluded NMN from the dietary-supplement definition in 2022 (citing prior drug investigation), then reversed that position in September 2025, declaring NMN not excluded.
Purported Benefits
✓Reliably and dose-dependently raises blood NAD+ levels in humans, the biochemical rationale for its use
✓May modestly improve walking distance, grip strength, and gait speed in some trials of healthy older or middle-aged adults (preliminary, not consistently replicated)
✓A single small RCT found increased skeletal-muscle insulin sensitivity in prediabetic postmenopausal women, though other metabolic markers did not improve
✓Generally well tolerated at oral doses up to 900 mg/day over 1-3 months in short trials
Evidence by outcome
The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.
| Outcome | Evidence | Effect | Studies |
|---|---|---|---|
| Raises blood NAD+ levelsConsistently and dose-dependently elevates blood NAD+ across RCTs and MA; the firmest finding (target engagement). | Strong | ↑ benefit · large | 4 |
| Physical performance (walk distance, grip, gait)Some RCTs show modest gains; a 2025 MA found no benefit for muscle mass/strength/gait in over-60s. | Mixed | ↔ mixed · small | 4 |
| Metabolic markers (glucose, insulin, HbA1c, lipids)8-RCT MA found no effect; one small prediabetes RCT raised muscle insulin sensitivity but not other markers. | Mixed | — no effect · negligible | 3 |
| Skeletal-muscle insulin sensitivity (prediabetic women)Single 25-woman clamp RCT showed ~25% rise; authors themselves cautioned against clinical recommendation. | Preliminary | ↑ benefit · moderate | 1 |
| Safety / tolerabilityWell tolerated up to 900 mg/day over 1-3 months; long-term safety data are lacking. | Moderate | ↑ benefit | 3 |
Dosing & Compounds
Typical Dose
250–600 mg once daily by mouth; trials have used up to 900 mg/day. Blood NAD+ and 6-minute walk gains plateaued around 600 mg/day in one dose-ranging trial.
Active Compounds
Safety & Cautions
Short-term oral NMN (up to 900 mg/day for 1-3 months) was well tolerated in trials, with no serious adverse events; mild GI upset is occasionally reported. Long-term safety is unknown, and theoretical concerns exist about whether boosting NAD+ could fuel growth of existing cancers, so people with active or prior malignancy should be cautious and consult a clinician. There are no robust human data in pregnancy or breastfeeding, so it should be avoided in those groups. Regulatory status is unsettled and varies by country: the US FDA excluded NMN from the dietary-supplement definition in 2022 before reversing in 2025, and product quality/purity in the unregulated supplement market is variable. No major drug-interaction data exist; those on medications (especially for diabetes, given possible effects on insulin sensitivity) or with significant medical conditions should consult a healthcare provider before use. NMN is not a treatment for any disease and benefits for aging or longevity remain unproven. Educational only — always check with your doctor or pharmacist before combining NMN (Nicotinamide Mononucleotide) with any medicine.
Key Studies ★ 12 studies
Meta-analysis
Song 2024
✓ PubMed
Meta-analysis of 8 RCTs (n=342, 250-2000 mg/d, 14 days-12 weeks) found NMN significantly elevated blood NAD+ levels but produced no significant benefit on fasting glucose, fasting insulin, HbA1c, HOMA-IR, or lipid profile.
Meta-analysis
Prokopidis 2025
✓ Full text
Systematic review and meta-analysis of 10 RCTs (6 NMN, 4 NR) concluded current evidence does not support NMN/NR supplementation for preserving skeletal muscle mass, handgrip strength, or gait speed in adults over a mean age of 60 years.
Systematic review
Nadeeshani / systematic review 2024
✓ Full text
Systematic review of 10 RCTs (437 patients, mean age 58.0 years, mean follow-up 9.6 weeks, doses 150-1200 mg/day) found NMN non-significantly improved physical performance parameters and was well tolerated with no serious adverse effects.
Meta-analysis
NMN Blood Pressure Meta-analysis 2026
✓ Full text
Systematic review and meta-analysis of RCTs (databases searched through Dec 2025) evaluated NMN supplementation on resting systolic and diastolic blood pressure in adults with elevated blood pressure, with subgroup analyses by age, BMI, dose, and duration.
Regulatory/agency statement
Regulatory determination
✓ Source
On September 29, 2025, the FDA reversed its 2022 position and concluded NMN is not excluded from the dietary-supplement definition, finding evidence it was marketed as a supplement before drug-investigation authorization.
Systematic review and meta-analysis
8 RCTs, 342 adults
✓ PubMed
A systematic review and meta-analysis found NMN (250-2000 mg/day) reliably raised blood NAD+ but showed no significant benefit on fasting glucose, fasting insulin, HbA1c, HOMA-IR, or lipid profile.
Systematic review
10 RCTs, 437 patients
✓ Full text
A systematic review of physical-performance outcomes concluded NMN may help preserve physical performance and reduce fatigue, but findings were inconsistent, with some trials (e.g., in diabetic women and runners) reporting null effects.
RCT
Yoshino et al. (Science, 2021)
✓ PubMed
Landmark 10-week double-blind RCT in 25 postmenopausal prediabetic overweight/obese women: NMN 250 mg/day increased insulin-stimulated glucose disposal (hyperinsulinemic-euglycemic clamp) by ~25% and upregulated skeletal-muscle insulin signaling (AKT/mTOR) and muscle remodeling genes; no change in placebo. First human evidence of an NMN metabolic benefit, though body weight, liver fat, and other metabolic markers were unchanged.
RCT
Kim et al. (Nutrients, 2022)
✓ PubMed
12-week double-blind placebo-controlled RCT in 108 older Japanese adults (NMN 250 mg/day, AM vs PM dosing). Afternoon NMN intake improved lower-limb function (5-times sit-to-stand, effect size d=0.72) and reduced drowsiness (d=0.64) versus placebo; timing-dependent benefit on physical performance and fatigue.
Randomized controlled trial
80 healthy middle-aged adults
✓ PubMed
In a dose-ranging RCT, 300/600/900 mg/day NMN for 60 days significantly raised blood NAD+ and improved 6-minute walk distance versus placebo, with effects plateauing around 600 mg/day; no safety issues were observed.
Randomized controlled trial
25 prediabetic postmenopausal women
✓ Full text
A 10-week RCT found 250 mg/day NMN increased skeletal-muscle insulin sensitivity and insulin signaling versus placebo, but did not change other metabolic-health markers, so the authors cautioned against clinical recommendations.
Randomized controlled trial
31 healthy older men
✓ Full text
A 12-week RCT of 250 mg/day NMN significantly increased whole-blood NAD+ and partly improved muscle function (gait speed, grip strength) in healthy older men, and was safe and well tolerated.