Nicotinamide adenine dinucleotide (NAD) is a coenzyme found in all living cells. The compound is a dinucleotide, because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine base and the other nicotinamide. Nicotinamide adenine dinucleotide exists in two forms, an oxidized and reduced form abbreviated as NAD+ and NADH respectively.
NAD is the abbreviation of Nicotinamide Adenine Dinucleotide. NAD is white powder, easily soluble in water, insoluble in other organic solvents. NAD exists in two forms: oxidized form NAD+ and reduced form NADH. In metabolism, NAD is a cofactor, involved in redox reactions, by carrying electrons from one reaction to another.
NAD powder is helpful for improving metabolism. NAD beta nicotinamide adenine dinucleotide can potentially prolong the lifespan of cells, thus NAD beta nicotinamide adenine dinucleotide may have anti-aging effect. NAD powder can be used in supplements, and NAD beta nicotinamide adenine dinucleotide is also be added to pharmaceuticals for treatment of various diseases.

Nicotinamide adenine dinucleotide, abbreviated NADh+, is a coenzyme found in all living cells. The compound is a dinucleotide, since it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine base and the other nicotinamide.
In metabolism, NAD+ is involved in redox reactions, carrying electrons from one reaction to another. The coenzyme is, therefore, found in two forms in cells: NAD+ is an oxidizing agent - it accepts electrons from other molecules and becomes reduced. This reaction forms NADH, (Nicotinamide adenine dinucleotide) which can then be used as a reducing agent to donate electrons. These electron transfer reactions are the main function of NAD+. However, it is also used in other cellular processes, the most notable one being a substrate of enzymes that add or remove chemical groups from proteins, in posttranslational modifications. Because of the importance of these functions, the enzymes involved in NAD+ metabolism are targets for drug discovery.