NMN (Nicotinamide Mononucleotide)
NAD+ precursor for cellular energy and repair
What It Is
NMN is a direct precursor to NAD+, a coenzyme critical for energy metabolism, DNA repair, and sirtuin activation. NAD+ levels decline significantly with age, and restoring them is a central thesis of modern longevity science.
How It Works
NMN is converted to NAD+ via the enzyme NMNAT. NAD+ fuels mitochondrial oxidative phosphorylation (ATP production) and activates sirtuins — proteins involved in DNA repair, gene silencing, and metabolic regulation.
The Science
Effect of oral NMN on NAD+ metabolism in healthy middle-aged and older adults
Nature Aging (2022) · PubMed
12-week RCT showing NMN increased blood NAD+ levels in middle-aged adults.
MIB-626, an oral NMN formulation, increases NAD+ in healthy volunteers
Journal of Clinical Endocrinology & Metabolism (2023) · PubMed
Double-blind RCT demonstrating dose-dependent NAD+ elevation with NMN supplementation.
Dosage
Most human studies use 250–1000 mg/day orally. The MIB-626 trial used 1000 mg/day. Higher doses have not shown proportionally greater benefits.
Safety
Generally well-tolerated in human trials up to 1200 mg/day. No serious adverse effects reported. Long-term safety data (>1 year) is still limited. May interact with medications metabolized by the liver.
Skeptic's Corner
While animal data is impressive, human trials are still small and short-term. The largest RCT (MIB-626) showed NAD+ increases but mixed results on functional outcomes. We don't yet know if raising NAD+ in humans produces the dramatic effects seen in mice. Sinclair's personal advocacy, while compelling, comes with a financial conflict of interest.
Our Picks
Affiliate disclosure: We earn a commission on qualifying purchases. This does not influence our evidence ratings or editorial content.