NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every living cell, where it carries electrons in energy metabolism and serves as a substrate for several families of signaling enzymes. It is important to be clear from the start: NAD+ is not a peptide. It is a dinucleotide, a small organic molecule built from two nucleotides, and it is studied across metabolism, mitochondrial biology and aging research. PRIME supplies NAD+ as a research material for laboratory use only.
What is NAD+?
NAD+ consists of two nucleotides joined through their phosphate groups. One nucleotide carries an adenine base, and the other carries nicotinamide, a form of vitamin B3. The nicotinamide ring is the reactive part of the molecule: it accepts a hydride ion during oxidation reactions, converting NAD+ into its reduced form, NADH. The two forms together are often written as the NAD+/NADH pair, and the ratio between them is a widely used indicator of cellular redox state.
A closely related molecule, NADP+, carries an extra phosphate group. Its reduced form, NADPH, is used mainly in biosynthesis and antioxidant defense rather than energy production, which is why the two pools are studied separately.
Cells make NAD+ through several routes. The de novo pathway starts from the amino acid tryptophan. The Preiss-Handler pathway uses nicotinic acid (niacin). The salvage pathway recycles nicotinamide back into NAD+, with the enzyme NAMPT acting as a key control point. Precursors such as nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) enter this network at different steps and are widely used in research on NAD+ metabolism.
How NAD+ works: mechanism studied in research
NAD+ has two broad roles that researchers usually separate.
Redox coenzyme
In glycolysis and the citric acid (TCA) cycle, NAD+ accepts electrons from fuel molecules and becomes NADH. NADH then delivers those electrons to complex I of the mitochondrial electron transport chain, which drives ATP production through oxidative phosphorylation. In this role NAD+ is recycled rather than consumed, so the total pool stays roughly constant while the ratio of oxidized to reduced forms shifts with metabolic activity.
Substrate for NAD+-consuming enzymes
Several enzyme families break NAD+ apart as part of their reactions, releasing nicotinamide that must then be salvaged. The best studied are:
- Sirtuins: NAD+-dependent deacylases that remove acetyl and other groups from proteins, linking cellular energy status to gene regulation and mitochondrial function.
- PARPs (poly-ADP-ribose polymerases): enzymes activated by DNA damage that use NAD+ to build ADP-ribose chains as part of DNA repair signaling.
- CD38 and CD157: cell-surface and intracellular NAD+-hydrolyzing enzymes that have been studied as major consumers of NAD+ in tissues.
Because these enzymes compete for the same pool, researchers are interested in how NAD+ availability shapes the balance between metabolism, repair and signaling. Declining NAD+ levels with age have been observed in a number of animal models, which is one reason NAD+ biology features prominently in aging research.
Areas of research
- Cellular energy metabolism: the NAD+/NADH ratio and its influence on glycolysis, fatty acid oxidation and mitochondrial respiration.
- Aging biology: studies of age-associated changes in NAD+ levels in rodent tissues and the effects of precursors in animal models.
- Sirtuin signaling: how NAD+ availability regulates sirtuin activity and downstream protein modification.
- DNA repair: the relationship between PARP activation, NAD+ consumption and genomic stability.
- Mitochondrial and neurological research: NAD+ metabolism has been investigated in cell and animal models of mitochondrial dysfunction and neurodegeneration.
These are areas of active investigation, and results in cells or animals do not establish any effect in people.
NAD+ key facts
| Property | Detail |
|---|---|
| Compound class | Coenzyme (dinucleotide); not a peptide |
| Structure | Adenine nucleotide and nicotinamide nucleotide joined by a pyrophosphate bridge |
| Reduced form | NADH |
| Main roles studied | Redox coenzyme; substrate for sirtuins, PARPs and CD38 |
| Form supplied | Lyophilized powder in a sealed vial (see product page for vial size) |
| Research status | Research material supplied for laboratory use only |
| Storage | Cold, dry and protected from light; refrigerate after reconstitution |
Handling and storage in the lab
NAD+ is supplied as a dry powder, which is its most stable form. Keep unopened vials cold and dry, away from light, and let a refrigerated vial reach room temperature before opening to prevent condensation. NAD+ is known to be sensitive to heat and to degrade more readily in alkaline solutions, so solution conditions matter for experiments that run over several days.
For lab work, the powder is commonly reconstituted with bacteriostatic water or with a buffer suited to the assay. Add the diluent gently and swirl until dissolved rather than shaking. Once in solution, keep it refrigerated and protected from light, record the concentration and date on the vial, and prepare fresh solutions for sensitive enzymatic or cell-based assays. Avoid repeated freeze-thaw cycles.
Follow standard laboratory safety practice, including gloves and eye protection, and your institution's rules for chemical handling and disposal.
Quality and lab results
For a molecule used in enzymatic and metabolic assays, identity and purity directly affect results. Every batch of NAD+ sold by PRIME is tested by an independent laboratory, and each certificate of analysis is posted on the lab results page. Check the COA that matches your lot number before use and keep it with your experiment records.
Current vial sizes and batch details are listed on the NAD+ product page.
Related research
- Epithalon vs NAD+: how a short peptide and a coenzyme are each studied in aging research.
- 5-Amino-1MQ research guide: an NNMT inhibitor studied for its effects on nicotinamide metabolism, which connects directly to the NAD+ salvage pathway.
- MOTS-c research guide: a mitochondria-derived peptide studied in metabolic research.
NAD+ FAQ
Is NAD+ a peptide?
No. NAD+ is a coenzyme, specifically a dinucleotide made of an adenine nucleotide and a nicotinamide nucleotide. It contains no amino acids. It is often sold alongside research peptides but belongs to a different chemical class.
What is the difference between NAD+ and NADH?
NAD+ is the oxidized form and NADH is the reduced form. NAD+ accepts electrons during metabolic reactions and becomes NADH, which then passes those electrons to the mitochondrial electron transport chain. The ratio between the two is used in research as a marker of cellular redox state.
What is the difference between NAD+, NMN and NR?
NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside) are precursors that cells convert into NAD+ through the salvage pathway. Research uses them to study how raising the supply of building blocks affects NAD+ levels, while NAD+ itself is the active coenzyme.
Why is NAD+ studied in aging research?
NAD+ levels have been observed to decline with age in a number of animal models, and NAD+ is required by sirtuins and PARPs, enzymes involved in metabolic regulation and DNA repair. That combination has made it a frequent subject of preclinical aging research.
How should NAD+ be stored?
Store the dry powder cold, sealed and protected from light and moisture. After reconstitution for lab use, keep the solution refrigerated, avoid alkaline conditions and heat, and prepare fresh solutions for sensitive assays.
For laboratory research use only. Not for human consumption. Not a drug, food or cosmetic.