NAD+: 500 mg ($30)
Overview
NAD+ is used to shuttle energy from the food we eat to the mitochondria in our cells all over the body. It is not a peptide; it is a coenzyme — a small molecule that a very large number of enzymes require in order to function — and it is present in every living cell. NAD+ is consumed as well as recycled in our cells, and levels decline naturally as we age, dropping significantly by middle age.
In plain terms
Chemical reactions in the body frequently involve moving electrons from one molecule to another. Enzymes carry out those reactions, but most cannot handle the electrons alone; they need a shuttle. NAD+ is that shuttle. It accepts electrons, becoming NADH, delivers them elsewhere, and reverts to NAD+ to repeat the cycle. This happens continuously, in enormous volume, as the central mechanism by which cells extract energy from food.
Beyond that metabolic role, NAD+ is consumed as a substrate — genuinely used up rather than recycled — by several families of enzymes involved in DNA repair and in regulating gene activity. Because those enzymes destroy NAD+ in the course of their work, cellular supply and demand for it becomes a subject of study in its own right. Measured NAD+ levels decline with age across a range of tissues, which is the observation underlying most current research interest.
Technical description
Nicotinamide adenine dinucleotide is a dinucleotide composed of nicotinamide mononucleotide and adenosine monophosphate joined by a pyrophosphate bridge. It cycles between oxidized (NAD+) and reduced (NADH) states as the principal hydride acceptor in catabolic oxidoreductase reactions, including glycolysis, the citric acid cycle, and fatty acid oxidation.
Distinct from its redox function, NAD+ serves as a consumed substrate for sirtuin deacylases (SIRT1–7), poly(ADP-ribose) polymerases (PARP1/2), and CD38/CD157 ectoenzymes, each cleaving the glycosidic bond and releasing nicotinamide. Cellular pools are maintained through the salvage pathway via nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting step, alongside de novo synthesis from tryptophan. As a large, charged, highly polar molecule, NAD+ exhibits poor passive membrane permeability, and the mechanism by which extracellular NAD+ influences intracellular pools is an active area of investigation.
- Full name
- β-Nicotinamide adenine dinucleotide
- Synonyms
- NAD, DPN, Coenzyme I
- CAS number
- 53-84-9
- Molecular formula
- C21H27N7O14P2
- Molecular weight
- 663.43 g/mol
- Class
- Dinucleotide coenzyme (not a peptide)
- Redox partner
- NADH (reduced form)
- Appearance
- White to off-white powder
- Storage
- −20 °C, desiccated, protected from light. Hygroscopic.
Regulatory status
NAD+ occurs naturally in food and in all living cells. Certain NAD+ precursors are marketed as dietary supplements; NAD+ itself supplied as a bulk research chemical is not a dietary supplement product and is not an FDA-approved drug for any indication. Material supplied for laboratory research is not manufactured, tested, or released under pharmaceutical or food-grade standards.