Nicotinamide adenine dinucleotide, abbreviated NAD⁺, 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.

Nicotinamide adenine dinucleotide phosphate, abbreviated NADP (or, in older notation, TPN (triphosphopyridine nucleotide)), is a coenzyme used in anabolic reactions, such as lipid and nucleic acid synthesis, which require NADPH as a reducing agent.