About NAD+
NAD+ (nicotinamide adenine dinucleotide) is a cellular coenzyme — not a peptide — central to redox reactions throughout metabolism. Together with its reduced form, NADH, it forms the NAD+/NADH redox couple that shuttles electrons through core metabolic pathways including glycolysis, the citric acid cycle and oxidative phosphorylation.
NAD+ is distinct from related compounds sometimes discussed alongside it, including NADH, nicotinamide, niacin, NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside) — these are biochemically related but not interchangeable, and findings about one should not be assumed to apply directly to another.
Beyond its redox role, NAD+ also functions as a direct substrate consumed by enzyme families including sirtuins and PARPs (poly-ADP-ribose polymerases), both active areas of metabolic and DNA-repair research. Reliable Research Labs supplies NAD+ as a 500 mg research compound, tested to ≥99.8% purity by HPLC analysis, strictly for qualified laboratory research. See our Compound Library entry for NAD+ for a wider overview.