Systematic review and meta-analysis

Efficacy of oral nicotinamide mononucleotide supplementation on glucose and lipid metabolism for adults: a systematic review with meta-analysis on randomized controlled trials

Jiaqi Zhang, Eric Tsz-Chun Poon, Stephen Heung-Sang Wong

Critical Reviews in Food Science and Nutrition · 2025 · 65(22):4382–4400

Original publication PubMed

Study at a glance

Design: Systematic review and meta-analysis of randomized controlled trials
Population or model: Adults enrolled in NMN randomized controlled trials
Sample size: 12 studies; 513 participants
Intervention: Oral NMN versus control across included randomized trials
Publication type: Systematic review and meta-analysis
Evidence class: review-perspective
Research area: Metabolic outcomes
Trial registration: Not applicable.

Study endpoints

Blood NAD-related measures
Glucose metabolism
Insulin resistance
Lipid metabolism
Body composition and related metabolic outcomes

Plain-language summary

This systematic review synthesized randomized trials of oral NMN in adults, focusing on glucose and lipid metabolism.

The review found that NMN reliably increased blood NAD-related measures, while evidence for improvements in conventional metabolic outcomes was inconsistent or not statistically convincing across pooled analyses.

The distinction matters: biochemical target engagement is better established than broad metabolic efficacy.

Key findings

Twelve studies involving 513 participants were included.
Blood NAD-related concentrations increased after NMN supplementation.
Evidence for consistent improvements in glucose and lipid metabolism was limited.
The review emphasized heterogeneity across doses, populations and trial designs.

Limitations

Underlying trials were generally small and short.
Substantial heterogeneity existed across study populations and interventions.
Many outcomes were surrogate biomarkers rather than clinical outcomes.
Results should not be interpreted as evidence of disease prevention or longevity.

Funding and transparency

Funding

See source publication for funding disclosures.

Competing interests

See source publication for competing-interest disclosures.

HealthspanX observation

The review reinforces the need to separate pharmacodynamic NAD effects from demonstrated clinical metabolic benefits.

Interpretive weight

Limited

Meta-analysis includes a larger set of RCTs but remains constrained by small, short and heterogeneous studies with limited clinical-outcome evidence.

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