Peptide Index
← Peptides
Metabolic

NAD+

Nicotinamide adenine dinucleotideNADbeta-NAD

Nicotinamide adenine dinucleotide — a redox coenzyme central to cellular energy metabolism. Not a peptide, but widely grouped with them in research-supply catalogues.

Overview

NAD+ is the outlier on this index: it is not a peptide. It is a dinucleotide coenzyme, with no amino-acid sequence, and it appears here because research-supply catalogues routinely list it alongside peptides and researchers arrive looking for it in the same place. See the guide what is NAD+? (and is it a peptide?) for the longer version.

Its role is twofold. As a redox carrier it cycles between NAD+ and NADH, shuttling electrons through glycolysis, the citric acid cycle and oxidative phosphorylation — the reaction that most textbooks describe. Less obviously, it is also consumed as a substrate by three enzyme families: sirtuins, PARPs and CD38. That consumption is what makes availability interesting, because those enzymes deplete the pool rather than recycling it, so NAD+ concentration becomes a limiting factor on their activity rather than a constant background.

Handling matters more than for most compounds on this index. NAD+ is labile in solution — it degrades under alkaline conditions, while its reduced partner NADH degrades under acid catalysis, leaving a narrow practical optimum near pH 8.5. Buffer choice therefore materially affects what is actually present in a preparation by the time it reaches an assay.

NAD+ is not a licensed medicine in the UK.

Mechanism, evidence & status

NAD+ is a dinucleotide coenzyme, not a peptide — it carries no amino-acid sequence. It cycles between oxidised (NAD+) and reduced (NADH) states as an electron carrier in glycolysis, the citric acid cycle and oxidative phosphorylation. Beyond redox chemistry it is consumed as a substrate by three enzyme families: sirtuins (protein deacetylases implicated in metabolic and stress-response regulation), PARPs (DNA-damage response), and CD38. Because those enzymes consume rather than recycle it, NAD+ availability is studied as a limiting factor in their activity.

Human evidence
Extensive basic biochemistry; precursor supplementation (NR, NMN) studied in humans with mixed results; intravenous NAD+ itself has limited controlled human data
Regulatory status
NAD+ is not a licensed medicine in the UK. Its precursors nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are sold as food supplements in some jurisdictions with differing legal status; intravenous NAD+ is administered in some private clinics on an unlicensed or compounded basis. Material sold by research-chemical suppliers is not quality-assured for human use.
Research applications
  • Study of redox balance and electron transfer in cellular energy metabolism.
  • Investigation of sirtuin, PARP and CD38 activity as NAD+-consuming pathways.
  • Research into the NAD+ precursor salvage pathway and the relative behaviour of NR and NMN.
  • Use as a reference cofactor in enzymology and metabolic assay development.
Safety considerations
  • Reported infusion-related effects in clinical and clinic settings include nausea, chest tightness, flushing and cramping, generally described as rate-dependent.
  • Long-term consequences of raising NAD+ availability are not established. Because PARP and sirtuin activity intersect with DNA repair and cell survival, the effect of sustained elevation is an open research question rather than a settled benefit.
  • NAD+ is chemically labile in solution — it degrades under alkaline conditions while NADH degrades under acid catalysis, with a practical optimum near pH 8.5. Handling conditions materially affect what is actually present.
  • Material sold by research-chemical suppliers is not a pharmaceutical-grade medicine and is not quality-assured for human or veterinary use.
Research parameters
Class
Dinucleotide coenzyme — not a peptide
Total content
1000 mg per kit

Fill volume is not published, so a concentration cannot be derived from the product record

Redox partner
NADH (reduced form)
Consuming enzyme families
Sirtuins, PARPs, CD38
Solution stability
Practical optimum near pH 8.5

NAD+ is labile under alkaline conditions; NADH degrades under acid catalysis

Reported research parameters drawn from the cited literature — provided for reference only. These are not dosing, usage, or medical recommendations.

References