NAD+ — nicotinamide adenine dinucleotide, oxidised form — is a central redox coenzyme present in every living cell. NAD+ is not a peptide; it is a small-molecule dinucleotide that serves as the electron-accepting substrate for hundreds of metabolic and signalling enzymes. Research-supply NAD+ and its biosynthetic precursors (nicotinamide riboside, nicotinamide mononucleotide) are studied in metabolic-research and ageing-biology contexts.
Definition
NAD+ is a small-molecule coenzyme composed of two nucleotides — nicotinamide mononucleotide (NMN) and adenosine monophosphate (AMP) — joined through a phosphodiester linkage. The coenzyme exists in two interconverting redox forms: NAD+ (oxidised, electron-accepting) and NADH (reduced, electron-donating). The NAD+/NADH ratio is the central redox couple driving electron flow through glycolysis, the tricarboxylic acid cycle, and the mitochondrial electron transport chain.
Beyond its role in redox metabolism, NAD+ is a substrate consumed by three families of NAD+-dependent signalling enzymes: the sirtuins (deacetylases involved in metabolic regulation and ageing biology), the PARPs (poly-ADP-ribose polymerases involved in DNA damage response), and the CD38/CD157 cyclic ADP-ribose synthetases. Each of these enzyme families cleaves NAD+ to produce nicotinamide and an ADP-ribosyl product, meaning cellular NAD+ pools are continuously consumed and must be regenerated by salvage and biosynthesis pathways using nicotinamide, nicotinamide riboside (NR), nicotinamide mononucleotide (NMN), and tryptophan as precursors.
How NAD+ and NAD+ precursors are studied in metabolic research
The published research on NAD+ biology and the therapeutic potential of NAD+ precursors has grown substantially since 2012. The Cantó characterisation of nicotinamide riboside (NR) documented enhanced oxidative metabolism and protection against high-fat diet-induced obesity in mouse models (PMID 22682224). The Yoshino review consolidates the biology and therapeutic-potential framework for NAD+ intermediates NMN and NR (PMID 29249689). Cancer-context research has examined the NAD+ metabolism enzyme NNMT in cancer-associated fibroblasts (PMID 39067875), extending the framing into oncology contexts.
Research-supply NAD+ is typically used in metabolic-research contexts where the direct cofactor is required (in-vitro enzyme assays, cell-culture supplementation studies, or research into the pharmacology of NAD+ administration itself). NAD+ precursor research (NR, NMN) typically uses the precursor rather than NAD+ directly because the precursor crosses cell membranes more efficiently than the larger dinucleotide.
Related terms
- Nicotinamide riboside (NR)
- Nicotinamide mononucleotide (NMN)
- Sirtuin (SIRT1-7)
- PARP (poly-ADP-ribose polymerase)
- CD38
- NAMPT (nicotinamide phosphoribosyltransferase)
- Oxidative phosphorylation
Where NAD+ appears in the Ronin catalog
- NAD+ 500mg — single-compound vial, lyophilized white powder under inert gas; supplied as the direct coenzyme rather than as the NR/NMN precursor
References
- Cantó C et al. The NAD(+) precursor nicotinamide riboside enhances oxidative metabolism and protects against high-fat diet-induced obesity. Cell Metab 2012;15(6):838-847. [PMID 22682224]
- Yoshino J et al. NAD(+) Intermediates: The Biology and Therapeutic Potential of NMN and NR. Cell Metab 2018;27(3):513-528. [PMID 29249689]
- Yang M et al. NAD(+) metabolism enzyme NNMT in cancer-associated fibroblasts drives tumor progression and resistance to immunotherapy by modulating macrophages in urothelial bladder cancer. J Immunother Cancer 2024;12(7):e009017. [PMID 39067875]
Glossary entries describe research-context use of peptide-research terminology. They do not constitute medical, veterinary, or clinical advice. NAD+ is sold strictly as a research-grade reagent for laboratory and bench research applications.