Reliably raises NAD+ blood levels in the trials available. A small signal also exists for muscle-function signals, but the marketed longevity, biological-age, and cognitive benefits remain unproven in humans. Short-term tolerability looks acceptable at trial doses, while long-term safety remains unstudied.
What the research says
Each row is a different health effect. A means the support looks strongest, B likely helpful, C mixed or modest, and — not enough human evidence yet.
Papers are individual studies. Research reviews summarize evidence from multiple studies, such as systematic reviews and meta-analyses.
B · Likely helpful
B
NAD+ blood levels (biomarker)
All usable papers show NMN raises NAD+. Biomarker effect confirmed — clinical significance of this effect is a separate question.
13 papers
C · Mixed or limited evidence
C
Insulin sensitivity / glucose
9 papers, reviews disagree. One meta-analysis finds insulin-sensitivity benefit at low doses (50 mg/day) specifically; others find no effect. Possible but unconfirmed.
9 papers
— · Not enough human evidence yet
—
Muscle function / aerobic capacity (older adults)
7 papers, mixed. One meta-analysis found a meaningful gait-speed improvement. Other trials show no significant change in strength or endurance.
7 papers
—
Biological age / epigenetic age
Only 1 qualifying human paper. This is the central claim behind NMN's longevity positioning — and it's essentially unstudied in humans. Proving "slower aging" requires decades-long trials that don't exist yet.
1 paper
—
Cardiovascular / blood pressure
4 papers. One meta-analysis found a modest blood-pressure reduction specifically in adults aged 60+. Not enough replication yet.
4 papers
—
Sleep quality
3 papers (2 positive, 1 null). One showed improvement on PSQI at 12 weeks. Too few papers to grade.
3 papers
—
Fatigue / energy / quality of life
3 papers, mixed. Evening NMN showed largest effect on sit-to-stand and drowsiness in one trial. Not enough evidence for a grade.
3 papers
—
Cognition / memory / neurological
Only 2 papers. The "NMN for brain health" marketing extrapolates from rodent papers that may not translate to humans.
2 papers
—
Skin aging / skin barrier function
No qualifying human trials found. A common consumer claim with no trial backing.
0 papers
Safety
Safety is graded separately from benefits. A favorable safety label is not the same as a benefit claim or a green light for every situation.
✓ SafeNo clear harm signal in the human evidence reviewed.
✓
Safety / adverse events / tolerability
6 papers, only 2 passed the quality filter. NMN appears well-tolerated at trial doses (250–900 mg/day) with no major safety signals reported. Long-term safety beyond one year remains unstudied.
6 papers · 2 usable
Quick facts
Dose and form from the papers available. Evidence base is young and mostly limited to short-term trials.
Typical dose
250–500 mg/day
Best taken
Morning. Timing not well-studied in human trials
Form
β-NMN is the active form. Major brands include Uthever and Mibellon. Sublingual claims lack human evidence
Common side effects
None significant in the trials reviewed
Drug interactions
None reported in the trials reviewed. NMN is a relatively new supplement; long-term interaction data is limited
Not the same as NR
Nicotinamide riboside (NR) is a different NAD+ precursor. NR has its own evidence base; do not conflate the two
Trial lengths
Most are 8–12 weeks. Long-term safety and efficacy beyond a year remain unstudied
Quality-verified products
Products that pass third-party quality testing.
Coming soon
Quality-verified NMN products will be listed with third-party purity testing. Given the evidence situation, the page clearly notes which marketed claims (NAD+ elevation, insulin sensitivity) are supported by the data and which (biological age, skin aging, cognitive enhancement) are not yet supported.
How we graded NMN
Grades come from 18 unique research papers indexed from PubMed — including 4 meta-analyses, 4 systematic reviews, and 10 randomized trials. Small evidence base. Most trials are short (8-12 weeks) and sample sizes modest. Long-term effects remain unstudied. Each supplement is graded by health effect using a certainty × effect matrix applied across PubMed evidence per health effect. Cochrane reviews and high-quality systematic reviews carry the most weight. From abstract-only data, "high certainty" is rare — most A grades come from moderate certainty plus consistent meaningful-positive evidence. See Methodology for full detail.