Raising NAD+: What It Does, What It Doesn't Prove Yet
What NMN and NR actually do, and what's still unproven
NMN and NR are precursor molecules — raw materials — that the body converts into NAD+, a molecule every cell needs to turn food into usable energy and to repair damaged DNA, and which reliably declines with age. Both NMN and NR reliably raise blood NAD+ levels in trials; that part is well-established. What's not yet established is whether raising NAD+ this way produces a meaningful lifespan or healthspan benefit in otherwise healthy people — the Longevity guide's Section 6 covers that open question in full.
Dose commonly used: 250–500 mg/day.
Confidence: Tier 3 — mechanistically plausible and biomarker-verified (it does raise NAD+), but without the direct human longevity outcome data that would justify higher confidence.
Section takeaway
NMN and NR reliably raise NAD+, a molecule central to cellular energy and DNA repair — but that biomarker change hasn't yet been shown to extend healthspan or lifespan in humans. A plausible bet, not yet a proven one.