NMN / NMNH (NAD+ Precursors)

NMN/NMNH restores NAD+ levels and targets genomic instability, mitochondrial dysfunction, and cellular senescence simultaneously, making it the broadest mechanistic intervention in longevity science. A landmark RCT (PMC9400576) showed 1250 mg/day of NMN safely raised blood NAD+ in 31 healthy adults, while earlier work on nicotinamide riboside demonstrated a 142% increase at 1000 mg/day (PMC6611812). NAD+ levels decline about 50% between ages 40 and 60, and a 2020 Nature Metabolism study revealed senescent cells drive this depletion via CD38-expressing macrophages. Optimal sublingual dosing of 500–1000 mg/day avoids first-pass degradation, and combination with resveratrol or TMG is common, though synergy data remain anecdotal.