What Is NAD+? Research Guide
Definition
NAD+ (nicotinamide adenine dinucleotide, oxidized form) is a dinucleotide coenzyme: CAS 53-84-9, C21H27N7O14P2, 663.4 Da, built from an adenosine monophosphate joined to nicotinamide mononucleotide through a phosphoanhydride bond. It contains no amino acids and no peptide bonds. It appears in this research library because the questions it answers overlap with those of the mitochondrial peptides beside it, not because it shares their chemistry.
Key Takeaways
- →NAD+ (nicotinamide adenine dinucleotide, oxidized form) is a dinucleotide coenzyme: CAS 53-84-9, C21H27N7O14P2, 663.4 Da, built from an adenosine monophosphate joined to nicotinamide mononucleotide through a phosphoanhydride bond. It contains no amino acids and no peptide bonds.
- →Available for in-vitro research at ≥99% HPLC-verified purity from Peptide.Express.
- →Certificate of Analysis included with every order. Same-day US shipping.
NAD+ Specifications
| Property | Value |
|---|---|
| Compound | NAD+ |
| CAS Number | 53-84-9 |
| Molecular Formula | C21H27N7O14P2 |
| Molecular Weight | 663.4 Da |
| Mechanism Class | Dinucleotide redox coenzyme and sirtuin/PARP substrate (not a peptide) |
| Purity | ≥99% by HPLC, batch-specific CoA included |
Registry records for NAD+: PubChem
NAD+ Mechanism of Action
NAD+ does two jobs, and conflating them is where most confusion about it starts. As a redox carrier it collects a hydride from glycolysis and the citric acid cycle, becomes NADH, hands those electrons to Complex I and returns to the oxidized form. Nothing is consumed in that cycle, and what matters is the NAD+/NADH ratio rather than the total amount present. As a signalling substrate it is destroyed. Sirtuins SIRT1 through SIRT7, PARP1 and PARP2, and the ectoenzyme CD38 each cleave the glycosidic bond and release nicotinamide, one molecule per reaction. That stoichiometry is the foundation of the whole aging literature: sirtuin Km values sit close enough to physiological NAD+ concentrations that a falling pool lowers activity rather than being buffered, and PARP1 responding to extensive DNA damage can draw the pool down fast enough to suppress sirtuins as a side effect. NAMPT runs the salvage pathway that rebuilds it and is the rate-limiting step in recovery. One question is genuinely unsettled: whether intact NAD+ crosses the plasma membrane. Substantial work indicates that CD73 and CD38 hydrolyze extracellular NAD+ to nicotinamide riboside and nicotinamide before uptake, which would mean adding NAD+ to a culture medium delivers precursors rather than the dinucleotide. That is a live disagreement, and it is the strongest reason to build a precursor comparison arm into a design that depends on the answer.
NAD+ Research Applications
Sirtuin enzymology, where fluorogenic substrate turnover measured against a defined NAD+ concentration gives a direct dose-response instead of one inferred through a precursor conversion step.
PARP biology after genotoxic insult, with poly-ADP-ribose accumulation and pool depletion measured in parallel so the competition between the two consumer families is visible rather than assumed.
Pool quantification by enzymatic cycling assay or LC-MS/MS, reporting NAD+ and NADH separately. The ratio carries the information; a single total figure conceals it.
Paired designs with MOTS-c, which raises NAMPT expression through AMPK. Supplying the substrate alongside the signal removes availability as a confounder. No published study characterizes that pairing directly, so it remains a reasoned design rather than a validated one.
NAD+ Storage Requirements
Lyophilized NAD+ keeps for 24 months at -20°C (-4°F), desiccated and light-protected, which reads like every peptide in this library. Its behaviour in solution does not. Reconstituted NAD+ should be used within 24 to 48 hours, against the 14 to 28 days a peptide solution allows: hydrolysis proceeds at the glycosidic and pyrophosphate bonds even at 4°C and accelerates sharply above neutral pH. Prepare the volume an experiment will consume and no more, check the pH of any buffered dilution before it costs you material, and label with the hour rather than the date alone. Researchers arriving from peptide work lose the most material here, because the number their instincts supply is two weeks.
NAD+ at Peptide.Express
All NAD+ sold by Peptide.Express is HPLC-verified at ≥99% purity with a Certificate of Analysis included. Same-day US shipping on orders before 2 PM EST. For in-vitro laboratory research use only.
View NAD+ Product DetailsFrequently Asked Questions
Is NAD+ a peptide?
No. NAD+ is a dinucleotide coenzyme — two nucleotides joined by a pyrophosphate bond — containing no amino acids and no peptide bonds. It is catalogued alongside research peptides because it is studied against the same mitochondrial and metabolic endpoints, not because it belongs to the same chemical class. Enclomiphene sits in this library for a comparable reason.
What is NAD+ and why is it studied?
NAD+ is nicotinamide adenine dinucleotide in its oxidized form: CAS 53-84-9, molecular formula C21H27N7O14P2, average molecular weight 663.4 Da. It carries electrons from glycolysis and the citric acid cycle to Complex I, and it is the consumed substrate of sirtuins, PARPs and CD38. Research interest concentrates on that second role, because enzymes that destroy NAD+ rather than recycling it make the size of the cellular pool a ceiling on their own activity.
What is the difference between NAD+ and NMN?
NMN, nicotinamide mononucleotide, is the immediate precursor at 334.2 Da; NAD+ is the finished coenzyme at 663.4 Da. Converting one into the other requires an NMNAT enzyme. Sirtuins and PARPs use NAD+ directly and cannot use NMN. For enzymology where substrate concentration has to be defined, NAD+ is the correct reagent; for asking whether a cell can rebuild its own pool through the salvage pathway, NMN is. Substituting silently changes what is being measured.
Why do NAD+ levels decline with age?
Two processes moving in opposite directions. Consumption rises: CD38 expression increases with age and inflammation, and accumulating DNA damage drives PARP activity, both drawing on the same pool. Synthesis falls, with reduced NAMPT activity slowing the salvage pathway that recycles nicotinamide back into NAD+. The decline has been measured across multiple tissues and organisms. Whether it is a cause or a consequence of aging is still open.
Does NAD+ enter cells intact?
Disputed, and worth stating plainly. A substantial body of work indicates that CD73 and CD38 hydrolyze extracellular NAD+ into nicotinamide riboside and nicotinamide before it crosses the plasma membrane, which would mean adding NAD+ to a culture medium supplies precursors rather than the dinucleotide itself. Other work argues for some direct uptake. Any design whose interpretation turns on the answer needs a precursor comparison arm.
How stable is reconstituted NAD+?
Much less stable than a peptide solution, and this is the most useful practical fact on the page. Use reconstituted NAD+ within 24 to 48 hours rather than the 14 to 28 days a peptide allows. Degradation runs at the glycosidic and pyrophosphate bonds, continues at 4°C and speeds up markedly above neutral pH, so keep preparations cold, near neutral and freshly made.
Where can I buy NAD+ for research?
Research-grade NAD+ is available from Peptide.Express at ≥99% HPLC-verified purity with LC-MS/MS mass confirmation and a batch-specific Certificate of Analysis. Visit peptide.express/catalog/nad for full specifications.
References
- Imai S, Guarente L. "NAD+ and Sirtuins in Aging and Disease." Trends in Cell Biology. 2014. Read the Imai and Guarente 2014 NAD+ and sirtuins aging review
- Covarrubias AJ, Perrone R, Grozio A, Verdin E. "NAD+ Metabolism and Its Roles in Cellular Processes during Ageing." Nature Reviews Molecular Cell Biology. 2021. Read the Covarrubias 2021 NAD+ metabolism and ageing review
- FDA drug approvals and databases. NAD+ does not appear as an approved injectable drug product; nicotinamide-based compounds are regulated in other categories. Search the FDA drug approval databases
Research Areas Using NAD+
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How This Page Is Sourced
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