Digestery
Longevity supplements › NMN and Aging › Studies

Pooled review (meta-analysis)

Pooled review of 27 studies in 1,599 adults: NMN helped endurance, not strength

Gao and colleagues · Frontiers in nutrition · 2026

Original title: Domain-specific effects of NAD+ precursors on fatigue and functional performance: a systematic review and network meta-analysis.

Under review. A person has not yet checked this summary against the paper. It is written from the PubMed abstract. Until a person checks it, search engines are asked not to list this page.

What the study found

Mixed

No precursor clearly improved felt fatigue or sleep. NMN improved endurance (high dose: SMD = 1.02, 95% CI 0.43-1.60); strength did not change. Quality of life rose with NMN (high dose: SMD = 0.56, 95% CI 0.14-0.98).

The study at a glance

Type of study
Pooled review (meta-analysis)
Who or what was studied
27 studies, 1,599 people · Adults in 27 studies of NAD+ precursors (NR, NMN, NADH, NAM)
What was tested
NAD+ precursors at different doses vs control, looking at fatigue, endurance, strength and quality of life
What it measured
Other health or performance measures
Trial registration
CRD420251237193
Who has a stake
No stake declared
No commercial or financial relationships declared.
Journal
Frontiers in nutrition, 2026
Source
PubMed record 42774067. This page is based on the abstract only.

How much this study counts

  • ✓Pools the results of 27 studies with 1,599 people.
  • •A pooled review is only as strong as the studies it pools.
  • •Measured other health measures, not aging and age-related decline itself.
  • ✓No competing interests declared.
  • •Summarized from the PubMed abstract only. The full paper may hold details the abstract leaves out.

✓ Strength– Limit• Note

These points come from fixed rules about the type of study, its size and length, what it measured, and who has a stake. Every study on Digestery gets the same rules.

Where this study sits

This paper is not on the ladder. It is a pooled review (meta-analysis), and reviews and opinion pieces discuss studies that are already counted on the steps below.

↑ Stronger evidence

  1. Trials in people: aging and age-related decline

    0

    Not done yet. This is the step that would answer the question.

  2. Trials in people: other measures

    9

    3 benefit, 2 mixed, 4 no difference

  3. Trials in people: lab tests or safety

    7

    4 benefit, 1 mixed, 2 no difference

  4. Population studies

    0

    None among the papers we read.

  5. Blood levels and genes

    0

    None among the papers we read.

  6. Animals

    6

    5 benefit, 1 mixed

↓ Weaker evidence

  • Points to benefit
  • Mixed
  • No difference
  • No direction
  • Points to harm

How it fits with the other research

The short answer to “Does NMN slow aging?”

Not shown in people so far.

Confidence: very low. Based on 29 on-topic papers.

Read the full answer
  • Part of the finding “Strength and walking: small, mixed signals”.
  • Summed up in “What reviews found”: Pooled 27 studies with 1,599 people. NMN improved endurance (high dose: SMD = 1.02) and quality of life, but not strength. No NAD+ booster improved felt tiredness or sleep.
  • Marked as a key paper in the research timeline: Largest review: 27 studies, 1,599 people.
  • Open item for a person: Pooled reviews Chen 2024, Zhang 2025, Wang 2025, Yang 2026 and Gao 2026 likely share many trials; their people counts should not be added.

Other reviews on this question

See all 29 studies on this question

How this page was made

Label

First read of the abstract
Claude Sonnet
Independent second read
Claude Haiku
Differences settled
The two reads agreed on every checked field. Claude Opus 5.5.
Headline
Claude Sonnet, from the checked study record. A script checked its numbers and wording.
Numbers
Checked against the abstract by a script
“How much this study counts”
Fixed rules, the same for every study
Source check by a person
Not yet. Required before search engines may list this page.

Spot an error? Email a flag with a link to your source, or use the form on the question page.