Nicotinamide adenine dinucleotide (NAD+) is a dinucleotide coenzyme, not a peptide. It consists of nicotinamide mononucleotide and adenosine monophosphate joined through a pyrophosphate bridge, and NAD+ is the oxidized form of the NAD+/NADH redox couple. This product is the free acid of β-NAD+.

NAD+ accepts hydride ions in dehydrogenase reactions of glycolysis, the tricarboxylic acid cycle and other oxidative pathways. It is also consumed as a substrate by signalling enzymes: sirtuins (NAD+-dependent protein deacylases), poly(ADP-ribose) polymerases (PARPs) and the NAD+ glycohydrolases CD38 and CD157. These reactions link its intracellular concentration to metabolic and nuclear signalling.

NAD+ is used as a cofactor in dehydrogenase assays and in research on sirtuin and PARP biochemistry, ADP-ribosylation and metabolic signalling. The solid is hygroscopic. In solution it hydrolyses, especially under alkaline conditions, so aqueous stocks should be prepared fresh and kept cold.

Research use only. This material is sold for in-vitro laboratory research and development purposes exclusively. It is not a drug, food, or dietary supplement, has not been evaluated by the FDA, and must not be used in humans or animals.