Nicotinamide Mononucleotide (NMN) for Aging
Despite striking results in mice, NMN has not been shown to slow human aging: the strongest pooled human evidence shows it raises blood NAD+ but fails to improve the clinical outcomes that actually matter. There is no human evidence it extends lifespan or healthspan.
Why this grade7-layer evidence engine
This claim earns a Counter-Evidence grade because the highest-quality human evidence is negative. A 2025 meta-analysis of glucose and lipid metabolism (PMID 39116016, n=513) found NMN raised blood NAD+ but left most clinically relevant metabolic outcomes unchanged, and the authors explicitly warned that NMN's benefits may be exaggerated. A second 2025 meta-analysis of muscle aging (PMID 40275690) found no significant effect on muscle mass, grip strength, or gait speed in adults over 60.
The supportive trials only reach surrogate endpoints. Two small, short, industry-funded RCTs (PMID 36482258, n=80; PMID 38789831, n=60) showed NAD+ rising and modest gains in walking or sleep, but PMID 38789831's pre-specified primary endpoint was null. No trial measures a hard lifespan or mortality outcome, and the dramatic mouse-longevity data have not carried over to humans.
Regulators and major clinics reinforce this caution. The US FDA states NMN 'is excluded from the definition of a dietary supplement,' and the EU EFSA's verdict is a safety opinion only (300 mg/day deemed safe), not an efficacy endorsement. The Mayo Clinic says such anti-aging approaches are 'not ready for prime time,' and the NIH's National Institute on Aging notes there is 'little, if any, science' behind supplement promises to help you live longer.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.504
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 negative 主導 (2 negative > 0 positive)，下層 RCT 不能推翻
- apply_hec_override — HEC-1 高階證據 negative — 強制由 C 改為 D
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 2 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status