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NAD+ — research-grade lyophilized peptide vial from Peptide.Express, ≥99% HPLC purity
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NAD+ (Nicotinamide Adenine Dinucleotide) — Dinucleotide Redox Coenzyme and Sirtuin/PARP Substrate

Research-Grade Compound

NAD+ (nicotinamide adenine dinucleotide, oxidized form) is a dinucleotide coenzyme — not a peptide — composed of an adenosine monophosphate unit joined to nicotinamide mononucleotide through a phosphoanhydride bond. Molecular formula C21H27N7O14P2, molecular weight 663.4 Da, CAS 53-84-9. It contains no amino acids and no peptide bonds, and it is listed alongside research peptides here only because the metabolic questions it answers overlap with theirs.

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Certificate Details
Purity≥99%
Methodology
HPLCLC-MS/MS
CAS Number53-84-9
Molecular FormulaC21H27N7O14P2
Molecular Weight663.4 g/mol
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This Certificate of Analysis was issued by an independent third-party laboratory. Peptide.Express does not conduct in-house testing. Results are provided as-is from the testing facility and confirm batch identity, purity, and analytical methodology. For questions about specific CoA results, contact [email protected].

≥99% by HPLCLC-MS/MS VerifiedCoA Every BatchIn-Vitro Research Use Only

What is NAD+?

NAD+ (nicotinamide adenine dinucleotide, oxidized form) is a dinucleotide coenzyme — not a peptide — composed of an adenosine monophosphate unit joined to nicotinamide mononucleotide through a phosphoanhydride bond. Molecular formula C21H27N7O14P2, molecular weight 663.4 Da, CAS 53-84-9. It contains no amino acids and no peptide bonds, and it is listed alongside research peptides here only because the metabolic questions it answers overlap with theirs.

The molecule does two jobs that are easy to conflate. As a redox carrier it accepts a hydride from glycolysis and the citric acid cycle, becoming NADH, then hands those electrons to Complex I of the electron transport chain and cycles back to NAD+. In that role it is a catalyst — recycled, not consumed. As a signalling substrate it is destroyed: sirtuins, PARPs and CD38 cleave the glycosidic bond and release nicotinamide, which means every deacylation reaction and every ADP-ribosylation event permanently removes an NAD+ molecule from the pool. The whole field of NAD+ decline research follows from that second fact.

One practical difference deserves stating up front, because it catches people who have only handled peptides. Reconstituted NAD+ solutions degrade considerably faster than reconstituted peptide solutions. Where a lyophilized peptide gives you 14 to 28 days at 2–8°C, NAD+ in solution should be used within 24 to 48 hours — it hydrolyses at the glycosidic and pyrophosphate bonds, and alkaline pH accelerates the process sharply. Prepare it fresh, in the volume the experiment needs, and do not treat a leftover vial as a stock.

How Does NAD+ Work? Mechanism of Action

Start with the redox function, because it sets the ceiling on everything else. NAD+ accepts electrons as NADH at three points in the citric acid cycle and one in glycolysis, then donates them at Complex I, feeding the proton gradient that ATP synthase converts into ATP. What matters biologically is not the absolute amount of NAD+ but the NAD+/NADH ratio — a cell with plenty of total nicotinamide dinucleotide but a reduced ratio cannot run oxidative metabolism, because the oxidized form is what the dehydrogenases need.

The signalling function is where the aging literature sits. Sirtuins — SIRT1 through SIRT7 — are NAD+-dependent deacylases that strip acetyl and other acyl groups from lysine residues on histones and transcription factors. SIRT1 acting on PGC-1alpha and the FOXO family governs mitochondrial biogenesis and stress-resistance programmes; SIRT3 does related work inside the mitochondrial matrix. Because these enzymes consume NAD+ stoichiometrically rather than using it catalytically, sirtuin activity is directly limited by NAD+ availability, and the Km values sit close enough to physiological concentrations that a falling pool translates into falling activity rather than being buffered away.

Two other consumers compete for the same pool. PARP1 and PARP2 use NAD+ for poly-ADP-ribosylation during the DNA damage response, and PARP1 in particular can drain cellular NAD+ rapidly when damage is extensive — an established route by which genotoxic stress suppresses sirtuin activity indirectly. CD38, an ectoenzyme that increases with age and inflammation, hydrolyses both NAD+ and its precursor NMN. Against these, NAMPT (nicotinamide phosphoribosyltransferase) runs the salvage pathway that recycles nicotinamide back into NMN and then into NAD+, and NAMPT is the rate-limiting step in that recovery.

The honest gap: whether intact NAD+ crosses the plasma membrane is disputed. A substantial body of work indicates that extracellular NAD+ is hydrolysed by CD73 and CD38 to nicotinamide riboside and nicotinamide before uptake, meaning that what enters the cell is a precursor rather than the dinucleotide itself. That is a real mechanistic controversy, not a technicality — it changes how an experiment adding NAD+ to a culture medium should be interpreted, and it is the strongest argument for including a precursor comparison arm in any study design.

Research Applications of NAD+

Sirtuin and Epigenetic Research

  • Sirtuin deacylase activity assays: fluorogenic substrate turnover measured against NAD+ concentration, which gives a direct dose-response rather than an inferred one.
  • PGC-1alpha and FOXO acetylation state: immunoprecipitation followed by acetyl-lysine blotting, linking NAD+ availability to a transcriptional programme.
  • Mitochondrial biogenesis endpoints: mitochondrial DNA copy number and TFAM expression downstream of SIRT1 and SIRT3 activity.

DNA Repair and PARP Biology

  • PARP1 activation models: poly-ADP-ribose accumulation after genotoxic insult, with NAD+ depletion measured in parallel to show the competition directly.
  • NAD+ pool quantification: enzymatic cycling assays or LC-MS/MS for NAD+ and NADH separately, since the ratio carries the information rather than the total.
  • CD38 activity studies: the ectoenzyme that consumes both NAD+ and NMN and rises with age, relevant whenever a model involves inflammatory tissue.

Mitochondrial and Metabolic Models

  • Complex I function: NADH-linked respiration measured against succinate-linked respiration to separate substrate supply from chain capacity.
  • Salvage pathway characterization: NAMPT expression and activity, the rate-limiting step that determines how fast a depleted pool recovers.
  • Combined signalling and substrate designs: NAD+ paired with MOTS-c, where AMPK activation raises NAMPT expression and the substrate question becomes explicit.

NAD+ vs NMN (Nicotinamide Mononucleotide)

FeatureNAD+NMN
IdentityThe active dinucleotide coenzymeImmediate biosynthetic precursor to NAD+
Molecular formulaC21H27N7O14P2C11H15N2O8P
Molecular weight663.4 Da334.2 Da
StructureTwo nucleotides joined by a pyrophosphate bondSingle nucleotide
Conversion stepNone — already the active formRequires NMNAT1/2/3 to become NAD+
Cell entryDisputed; largely degraded extracellularly to precursorsEnters via precursor transport routes, including Slc12a8 in some tissues
Direct sirtuin substrateYesNo — must be converted first
Solution stabilityPoor: use within 24–48 hoursBetter, but still shorter-lived than a peptide solution
Research useDirect substrate supply and enzymologyPrecursor flux and salvage pathway studies

The choice is not about which is stronger. NAD+ is what the enzymes actually use, so it is the right reagent for enzymology where substrate concentration must be known. NMN is the right reagent when the question is whether a cell can build its own pool through the salvage pathway. Substituting one for the other silently changes what the experiment measures.

NAD+ Technical Specifications

Technical specifications for NAD+, including molecular data, purity standard, testing methods and storage requirements.
Compound NameNAD+ (nicotinamide adenine dinucleotide, oxidized form)
Common SynonymsNicotinamide adenine dinucleotide, NAD plus, beta-NAD, coenzyme I, DPN
ClassificationDinucleotide redox coenzyme — not a peptide
CAS Number53-84-9
Molecular FormulaC21H27N7O14P2
Molecular Weight663.4 Da
Structural ComponentsAdenosine monophosphate linked to nicotinamide mononucleotide via a phosphoanhydride bond
Reduced FormNADH
Consuming EnzymesSirtuins (SIRT1-7), PARP1/2, CD38
Salvage Pathway EnzymeNAMPT (nicotinamide phosphoribosyltransferase), rate-limiting
Purity≥99% by HPLC
Purity ConfirmationLC-MS/MS molecular weight verification
Endotoxin TestingLAL (Limulus Amebocyte Lysate) method
Physical FormLyophilized powder
AppearanceWhite to off-white powder
ReconstitutionSterile water for injection preferred; bacteriostatic water acceptable where multi-access is required
Storage (lyophilized)-20°C, desiccated, protected from light
Storage (reconstituted)2–8°C, use within 24–48 hours — considerably shorter than a peptide solution
pH SensitivityDegrades rapidly at alkaline pH; keep preparations near neutral or slightly acidic
Shelf Life24 months from manufacture (lyophilized)
Testing MethodsHPLC, LC-MS/MS, LAL Endotoxin
DocumentationCertificate of Analysis (CoA) per batch
FDA StatusNot approved as an injectable drug product
Intended UseIn-vitro laboratory research only

How to Reconstitute NAD+ for Research

Treat NAD+ as a same-week reagent, not a stock solution. The lyophilized powder is stable for two years at -20°C, but once it meets water the clock runs in hours rather than weeks: hydrolysis at the glycosidic and pyrophosphate bonds proceeds steadily at 4°C and accelerates sharply above neutral pH. Reconstitute the amount an experiment needs, use it within 24–48 hours, and if a study spans several days, prepare fresh each day rather than drawing from one vial. Researchers coming from peptide work are the ones most likely to get this wrong, because 14–28 days is the number their instincts supply.

  1. Bring the vial to room temperature before opening, and plan the volume around what will be consumed in the next 24–48 hours rather than the vial size.
  2. Use sterile water for injection where the preparation will be used once. Bacteriostatic water is acceptable when a vial genuinely needs multiple accesses, but the short solution life means the preservative advantage rarely comes into play.
  3. Swab the septum with 70% isopropyl alcohol and allow 30 seconds to dry.
  4. Inject the diluent slowly against the inner vial wall. For a 500 mg vial, 5 mL yields 100 mg/mL; 10 mL yields 50 mg/mL. At 663.4 Da, 50 mg/mL is approximately 75 mM.
  5. Swirl gently until fully dissolved. NAD+ dissolves readily in water; the solution may carry a faint yellow cast, which is normal at higher concentrations.
  6. Check the pH of any buffered working dilution. Alkaline conditions degrade NAD+ quickly, so a buffer above pH 8 will cost you material before the assay starts.
  7. Label with the reconstitution date and time — not just the date. A 24–48 hour window makes the hour matter.
  8. Store at 2–8°C, protected from light, and use within 24–48 hours. Discard rather than salvaging leftovers for a later run.

Diluent: bacteriostatic water for peptide reconstitution. Full protocol: step-by-step peptide reconstitution guide. Concentration maths: peptide reconstitution calculator.

Frequently Asked Questions — NAD+

Is NAD+ a peptide?

No. NAD+ is a dinucleotide coenzyme — two nucleotides joined by a pyrophosphate bond. It contains no amino acids and no peptide bonds. It appears in peptide catalogs because it is studied alongside mitochondrial and metabolic research peptides, not because it belongs to the same chemical class.

What is NAD+ and why is it studied?

NAD+ (nicotinamide adenine dinucleotide, oxidized form, C21H27N7O14P2, 663.4 Da, CAS 53-84-9) is the electron carrier that links glycolysis and the citric acid cycle to Complex I of the electron transport chain, and the consumed substrate for sirtuins, PARPs and CD38. Research interest concentrates on the second role: because those enzymes destroy NAD+ rather than recycling it, the size of the cellular pool sets a ceiling on sirtuin activity, and that pool declines with age in multiple organisms.

How does NAD+ relate to sirtuins?

Sirtuins SIRT1 through SIRT7 are NAD+-dependent deacylases. They remove acetyl and other acyl groups from lysine residues on histones and transcription factors, and each reaction consumes one NAD+ and releases nicotinamide. SIRT1 acting on PGC-1alpha and FOXO proteins drives mitochondrial biogenesis and stress-resistance gene programmes. Because their Km values sit near physiological NAD+ concentrations, a falling pool produces falling activity rather than being buffered.

What is the difference between NAD+ and NMN?

NMN (nicotinamide mononucleotide, 334.2 Da) is the immediate precursor; NAD+ (663.4 Da) is the finished coenzyme. Converting NMN to NAD+ requires an NMNAT enzyme. NAD+ is the direct substrate for sirtuins and PARPs; NMN is not, and has to be converted first. For enzymology where substrate concentration must be defined, NAD+ is the correct reagent. For studying whether a cell can rebuild its own pool, NMN is.

Why do NAD+ levels decline with age?

Two processes running in opposite directions. Consumption rises — CD38 expression increases with age and inflammation, and accumulating DNA damage drives PARP activity, both of which draw 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; how much of it is cause versus consequence of aging remains an open question rather than a settled one.

How should NAD+ solution be handled — is it stable?

It is not, relative to peptides, and this is the single most useful practical fact on this page. Reconstituted NAD+ should be used within 24–48 hours, against the 14–28 days a reconstituted peptide solution typically allows. Degradation proceeds at the glycosidic and pyrophosphate bonds and accelerates markedly above neutral pH. Keep it cold, keep it near neutral, protect it from light, and prepare it fresh rather than working from a stored stock.

Does NAD+ enter cells intact?

Disputed, and worth saying plainly rather than glossing. Substantial evidence indicates that extracellular NAD+ is hydrolysed by CD73 and CD38 into nicotinamide riboside and nicotinamide before crossing the plasma membrane, which would mean that adding NAD+ to a culture medium delivers precursors rather than the dinucleotide itself. Other work argues for some direct uptake. A study design that depends on the answer should include a precursor comparison arm.

What is the PARP-NAD+ connection?

PARP1 and PARP2 consume NAD+ to build poly-ADP-ribose chains during the DNA damage response. When damage is extensive, PARP1 can deplete cellular NAD+ fast enough to suppress sirtuin activity as a side effect — one enzyme starving another of shared substrate. That competition is the mechanistic core of NAD+ research in ischemia-reperfusion, genotoxic stress and inflammation models.

Can NAD+ and MOTS-c be studied together?

That pairing is the rationale behind the Mitochondrial Fuel Stack. MOTS-c activates AMPK, AMPK raises NAMPT expression, and NAMPT is the rate-limiting enzyme of the NAD+ salvage pathway — so the signalling compound increases both the machinery for making NAD+ and the metabolic activity that consumes it. Supplying NAD+ alongside removes substrate availability as a confounder. No published study has characterized the combination directly, so it remains a mechanistically reasoned design rather than a validated one.

What concentration should NAD+ be prepared at?

For a 500 mg vial, 5 mL of diluent gives 100 mg/mL and 10 mL gives 50 mg/mL — roughly 150 mM and 75 mM respectively at 663.4 Da. Working concentrations in cell-based assays are typically far below that, so prepare a concentrated stock and dilute immediately before use, bearing in mind that the 24–48 hour window applies to the stock as well.

What purity standard does Peptide.Express use for NAD+?

≥99% by HPLC with LC-MS/MS confirming the 663.4 Da mass. The relevant impurities for a dinucleotide are its own hydrolysis products — nicotinamide mononucleotide and free nicotinamide — so the chromatogram is informative about how the material has been stored, not only about how it was made.

Where is the Certificate of Analysis for NAD+?

On this page and in the Peptide.Express lab results library, keyed to the batch number on the vial. Each CoA lists HPLC purity, LC-MS/MS identity confirmation, endotoxin result, testing laboratory and test date.

Research References

  1. 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
  2. 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
  3. 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

All products are sold for in-vitro laboratory research use only. Not intended for human consumption, clinical use, or veterinary use. Peptide.Express makes no medical claims. Consult the published literature for research application guidance.

Further Reading

Related Research Compounds

MOTS-cMitochondrial-derived peptide that activates AMPK and raises NAMPT expression upstream of the NAD+ salvage pathway.Mitochondrial Fuel StackMOTS-c and NAD+ in separate vials for signalling-plus-substrate study designs.SS-31 (Elamipretide)Cardiolipin-binding peptide addressing mitochondrial structure rather than substrate supply.Bacteriostatic WaterPreserved diluent, though the 24–48 hour NAD+ solution window limits the benefit of multi-use access.