NAD+

Nicotinamide Adenine Dinucleotide (NAD+) is an essential coenzyme found in every living cell. It plays critical roles in cellular energy metabolism, DNA repair (via PARP enzymes), epigenetic regulation (via sirtuins), and immune cell function. NAD+ levels decline 50% between ages 40–60, and restoring them is a major focus of longevity research.

Functions as an electron carrier in oxidative phosphorylation (NADH ↔ NAD+ redox cycling). Serves as a substrate for sirtuins (SIRT1-7), which regulate gene expression, inflammation, and cellular stress responses. Consumed by PARP enzymes during DNA repair. Also used by CD38 in immune signaling. Supplementation or IV infusion aims to restore the declining NAD+/NADH ratio.

IV NAD+ has a plasma half-life of approximately 30–45 minutes, but tissue levels remain elevated for 4–8 hours. Oral precursors (NMN, NR) have their own PK profiles. Subcutaneous NAD+ reaches peak levels in 1–2 hours with an effective duration of 4–6 hours. Typical IV infusion is 250–500mg over 2–4 hours.

Aging reversal, mitochondrial function, sirtuin activation, neuroprotection (Alzheimer's, Parkinson's), metabolic syndrome, cardiac function, exercise performance, DNA repair.

NAD+ biology is extensively researched (David Sinclair, Charles Brenner labs). Oral precursors NMN and NR have completed Phase 1–2 trials. Direct NAD+ IV infusion lacks large clinical trials but is used in integrative medicine clinics. FDA GRAS status for NR.

• NAD+ in aging and disease — Science · doi.org
• NAD+ metabolism review — Cell Metabolism · doi.org
• NAD+ decline with age — Nature Communications · pubmed.ncbi.nlm.nih.gov
• NMN oral bioavailability — Science · doi.org
• NR pharmacokinetics — Nature Communications · doi.org