NAD+ (Nicotinamide Adenine Dinucleotide) is a coenzyme central to cellular energy metabolism and a substrate for sirtuins and PARP enzymes involved in DNA repair and longevity signaling.
Administration Routes and Dosage
IV infusion: 250–1000 mg over 2–4 hours, 1–5x per week (highest bioavailability). Subcutaneous: 100–200 mg/day. Oral precursors (NMN, NR): 250–1000 mg/day (lower bioavailability than IV). IV administration is preferred for research requiring rapid NAD+ elevation.
Mechanism and Sirtuin Activation
NAD+ is the rate-limiting substrate for SIRT1-7 (sirtuins), which regulate gene expression, mitochondrial biogenesis, and DNA repair. Declining NAD+ with age reduces sirtuin activity — the primary rationale for NAD+ supplementation research.
Clinical Evidence
A 2023 Phase 2 trial showed IV NAD+ infusion significantly increased blood NAD+ levels and improved mitochondrial function markers. Long-term human studies on aging endpoints are ongoing.