Cellular Cofactors

What Defines a Cellular Cofactor?

A cofactor is a non-protein helper that an enzyme needs for activity. A coenzyme is a cofactor that is an organic molecule, often made from a vitamin. NAD+ is a coenzyme made from vitamin B3 forms (nicotinic acid, nicotinamide, nicotinamide riboside) or from the amino acid tryptophan [R3][R4].

NAD+ is studied for two roles. First, as a redox carrier: it switches between its oxidized form (NAD+) and reduced form (NADH) and moves electrons between metabolic reactions [R5]. Second, as a substrate: sirtuins, poly(ADP-ribose) polymerases (PARPs), and CD38 break NAD+ down as part of their reactions [R2].

Why NAD+ Is Not a Peptide

A peptide is a chain of amino acids joined by peptide bonds. NAD+ has none. It is two nucleotides, nicotinamide mononucleotide and adenosine monophosphate, joined through their phosphate groups [R6][R7]. That is why Sequora lists it under Cellular Cofactors.

Compounds in This Category

Sources: [R6][R7][R8][R9][R2]

Regulatory Status

Sequora supplies NAD+ as a research chemical. It is not sold as a drug, a dietary supplement, or a food. On FDA's list of substances nominated for 503A compounding, NAD is a Category 1 substance "under evaluation" (list updated May 14, 2026) [R10].

Cellular Cofactors FAQ

What is a cellular cofactor?

It is a non-protein molecule an enzyme needs in order to work. Organic cofactors such as NAD+ are called coenzymes [R1].

Is NAD+ a peptide?

No. NAD+ is a dinucleotide with no amino acids. It is built from two nucleotides joined through their phosphate groups [R6].

What is the difference between NAD+ and NADH?

NAD+ is the oxidized form and NADH is the reduced form. The pair carries electrons between metabolic reactions [R5].

What is NAD+ studied for in the lab?

It is studied as a redox cofactor and as the substrate that sirtuins, PARPs, and CD38 consume. Researchers use it in enzyme assays and in cell and animal models of NAD+ metabolism [R2]. Our NAD+ vs NMN vs NR article compares NAD+ with its precursors.

How do I check a batch?

Each batch comes with a certificate of analysis. Our guide How to Read a COA explains the HPLC and mass-spec sections.

References

1. Verdin E. NAD+ in aging, metabolism, and neurodegeneration. Science. 2015;350(6265):1208–1213. doi:10.1126/science.aac4854. PMID 26785480.
2. Covarrubias AJ, Perrone R, Grozio A, Verdin E. NAD+ metabolism and its roles in cellular processes during ageing. Nat Rev Mol Cell Biol. 2021;22(2):119–141. doi:10.1038/s41580-020-00313-x. PMID 33353981.
3. Bogan KL, Brenner C. Nicotinic acid, nicotinamide, and nicotinamide riboside: a molecular evaluation of NAD+ precursor vitamins in human nutrition. Annu Rev Nutr. 2008;28:115–130. doi:10.1146/annurev.nutr.28.061807.155443. PMID 18429699.
4. Reactome. Nicotinate metabolism (R-HSA-196807), Homo sapiens. reactome.org
5. Ying W. NAD+/NADH and NADP+/NADPH in cellular functions and cell death: regulation and biological consequences. Antioxid Redox Signal. 2008;10(2):179–206. doi:10.1089/ars.2007.1672. PMID 18020963.
6. PubChem. Nadide, CID 5892. National Center for Biotechnology Information. pubchem.ncbi.nlm.nih.gov/compound/5892
7. KEGG DRUG. D00002, Nadide. kegg.jp/entry/D00002
8. U.S. Food and Drug Administration. UNII 0U46U6E8UK, Nadide. Global Substance Registration System. precision.fda.gov
9. RCSB Protein Data Bank. Ligand NAD (nicotinamide-adenine-dinucleotide). rcsb.org/ligand/NAD
10. U.S. Food and Drug Administration. Bulk drug substances nominated for use in compounding under section 503A of the FD&C Act (updated May 14, 2026). fda.gov/media/94155/download

For laboratory research use only. Not for human or veterinary use.