○ Evidence tier 4 — Human RCT — biomarker endpoint

Record verify: verified against primary source

DesignSystematic review and meta-analysis of randomized controlled trials
DOI10.1007/s11892-024-01557-z
Citation statusdoi verified via Crossref 2026-07-12 (Curr Diab Rep 2025;25, 'Effects of Nicotinamide Mononucleotide on Glucose and Lipid Metabolism in Adults: A Systematic Review and Meta-analysis of Randomised Controlled Trials'). A second concordant meta-analysis (Crit Rev Food Sci Nutr 2025;65:4382-4400, doi 10.1080/10408398.2024.2387324) reaches a similar null conclusion. PMID is not confirmed; see identifier status.

Identifiers: DOI verified; PMID not reported; trial registry id not applicable to this study type. Record-level verification and identifier-level status are separate: a record can be verified against its primary publication on one identifier while another is simply not confirmed. No identifier is fabricated, and none is left in a “pending” state.

Five-qualifier claim

Species / populationAdults pooled across randomized controlled trials of NMN (systematic review and meta-analysis).
Exposure, route, scheduleOral NMN across included RCTs (varied doses/durations).
Comparator / durationPlacebo-controlled RCTs pooled; meta-analytic synthesis.
Endpoint / numeric resultNo statistically significant effect of NMN on glucose or lipid metabolism across the pooled RCTs.
What it did NOT establishA null meta-analysis for metabolic biomarkers — it does not support a metabolic, functional, or lifespan benefit of NMN.

Primary reference

https://doi.org/10.1007/s11892-024-01557-z

Exact identifier confirmed against the primary record via Crossref/ClinicalTrials.gov where stated in the citation status names the source and the date. An identifier that is not confirmed is named as such in the identifier row above, never filled in from a secondary source.