NMN / NR (NAD+ precursors) slow aging
Spectacular mouse data, underwhelming human data. NAD+ levels do rise; downstream effects on aging endpoints in humans are tiny. $50/month for ambiguous benefit.
What the evidence says
The studies, decoded
Rodent studies (Sinclair lab, Imai lab) show dramatic effects on metabolism and lifespan extension. Human RCTs are far weaker: Yoshino 2021 (NMN, postmenopausal women) showed modest improvement in insulin sensitivity. Martens 2018 and Dollerup 2018 (NR) confirmed NAD+ raises but found minimal effects on metabolic or aging biomarkers. The species translation problem is real here — the mouse-to-human gap is wider than for most supplements.
How it actually works
Mechanism
NMN and NR are precursors to NAD+, a coenzyme central to mitochondrial function and sirtuin signaling. NAD+ declines with age. Supplementing precursors raises NAD+ levels in tissue. Whether higher NAD+ in already-adequate humans does anything material is the open question.
What to actually expect
Realistic outcome
500mg-1g/day NMN or 300-500mg NR. NAD+ levels will rise. Whether your skin, mood, energy or aging slow meaningfully is uncertain. Significant cost ($30-80/month). Not in the same league of evidence as creatine, finasteride or minoxidil.
If this is overhyped — what is not
Better alternatives
Exercise (especially zone 2 cardio) raises NAD+ naturally. Adequate sleep, calorie restriction, niacin (cheap precursor) for those who actually have low NAD+. If you want anti-aging — sun protection, retinoid, sleep, weight management dominate any supplement.
Sources
Citations
- NMN in postmenopausal prediabetic women — RCTYoshino et al., 2021, Science
- NR supplementation effects on NAD metabolism in healthy adultsMartens et al., 2018, Nat Commun
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