This article is for laboratory and research information only. All products referenced are supplied strictly for research use and are not for human or veterinary use. Last reviewed: October 2026.
Quick answer: NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every living cell. It carries electrons in energy metabolism and is used up by enzyme families such as sirtuins and PARPs. It is widely studied in mitochondrial, metabolism and ageing research. NAD+ is not a peptide but a dinucleotide, and research-grade NAD+ is sold in the UK for laboratory use only.
NAD+ at a glance
| Full name | Nicotinamide adenine dinucleotide (oxidised form) |
| Type of molecule | Dinucleotide coenzyme (not a peptide) |
| Reduced form | NADH |
| Molecular weight | Approximately 663.4 g/mol |
| First described | 1906, by Arthur Harden and William Young |
| Sensitivity | Light and moisture sensitive |
| UK status (research grade) | Supplied as a research chemical for laboratory use only |
What is NAD+?
NAD+ is a coenzyme made of two nucleotides joined together: one containing adenine and one containing nicotinamide, which is a form of vitamin B3. It exists in two states. NAD+ is the oxidised form, which accepts electrons, and NADH is the reduced form, which carries them.
It was first described in 1906 by the British biochemists Arthur Harden and William Young, during their work on yeast fermentation. Because it is involved in so many cellular reactions, it is one of the most studied molecules in biochemistry.
Is NAD+ a peptide?
No. Peptides are chains of amino acids, while NAD+ is a dinucleotide built from sugars, phosphates and nitrogen-containing bases. It is often sold alongside research peptides because it is used in similar areas of laboratory research and supplied in similar formats.
What is NAD+ studied for?
NAD+ research spans several decades. The main areas are:
- Energy metabolism: NAD+ and NADH shuttle electrons in glycolysis, the citric acid cycle and the mitochondrial electron transport chain.
- Sirtuin activity: sirtuins are a family of enzymes that require NAD+ to function. They are studied for their role in gene regulation and cellular stress responses.
- PARP enzymes and DNA repair: PARPs consume NAD+ as part of the cellular response to DNA damage.
- Ageing models: studies, mainly in animal models, have reported that NAD+ levels fall in some tissues with age. This has made NAD+ and its precursors a major topic in ageing research.
Much of the ageing-related NAD+ research is preclinical. Human data is still developing, and findings in animal models do not necessarily carry over.
NAD+ vs NAD+ precursors
Research on NAD+ often also involves its precursors, which cells convert into NAD+. The most commonly studied are nicotinamide riboside (NR), nicotinamide mononucleotide (NMN), nicotinamide and nicotinic acid (niacin). Precursor research looks at how cells build NAD+, while NAD+ itself is used to study the coenzyme directly.
Why is NAD+ supplied in larger quantities?
NAD+ is used at higher concentrations than most peptides in laboratory protocols, so it is typically supplied in larger amounts, such as 500mg, rather than the 5–10mg common for peptides.
Vials vs pre-filled pens
- Lyophilised vial (NAD+ 500mg): freeze-dried powder for reconstitution in the lab. This is the most stable format for storage.
- Pre-filled pen (NAD+ 500mg Pen): supplied ready-mixed, with no reconstitution step, and a shorter storage window once in solution.
Both are supplied in light-protective packaging. For more on the two formats, see lyophilised vials vs pre-filled pens.
What to check when buying NAD+ in the UK
- A batch-specific Certificate of Analysis (CoA) showing purity and identity.
- Endotoxin testing, especially for material intended for cell-culture work.
- Light-protective packaging, since NAD+ degrades when exposed to light.
- Clear storage guidance and cold storage before dispatch.
See our guide on how to read a Certificate of Analysis.
Storage
Keep NAD+ cold, dry and protected from light. Lyophilised NAD+ is best stored frozen or refrigerated in its sealed vial. Once in solution it is less stable, so keep it refrigerated, protected from light, and use it within its stability window. See our storage & reconstitution guide.
NAD+ FAQ
What does NAD stand for?
Nicotinamide adenine dinucleotide.
What is the difference between NAD+ and NADH?
NAD+ is the oxidised form, which accepts electrons. NADH is the reduced form, which carries them.
Is NAD+ related to vitamin B3?
Yes. The nicotinamide part of NAD+ is a form of vitamin B3, and B3 compounds are among the precursors cells use to make NAD+.
Why does NAD+ need protecting from light?
NAD+ is light sensitive and can degrade with exposure, which is why it is supplied in dark vials or light-protective packaging.