NAD+: A Research Guide to the Cell's Central Redox Cofactor
By Peptura Research Team/22 May 2026/7 min read
What NAD+ Is
Nicotinamide Adenine Dinucleotide (NAD+) is a coenzyme found in every living cell and central to cellular bioenergetics. It is not a peptide but a dinucleotide, nicotinamide mononucleotide joined to adenosine monophosphate, with a molecular weight of roughly 663 Da. The oxidised form (NAD+) and the reduced form (NADH) work together as the principal electron carriers of cellular respiration.
Beyond that redox chemistry, NAD+ is a substrate for several enzyme families that loom large in ageing, DNA repair, and metabolic regulation research, which is why it has become one of the most investigated small molecules in cellular biology over the past two decades. Peptura supplies NAD+ as research-grade lyophilised powder for in-vitro laboratory use only.
Carrying Electrons Through Respiration
In its primary metabolic role, NAD+ accepts electrons during glycolysis, beta-oxidation, and the citric acid cycle, becoming NADH, which then hands those electrons to the electron transport chain at complex I of the inner mitochondrial membrane. The proton gradient that follows drives ATP synthesis. Cut off the steady supply of NAD+ as electron acceptor and the major catabolic pathways stall, which is why cellular NAD+ is tightly regulated and why its depletion is such a common source of metabolic dysfunction in research models.
Feeding the Sirtuins, PARPs and CD38
Beyond redox duty, NAD+ is consumed as a substrate by three main enzyme families. The sirtuins, SIRT1 through SIRT7, are NAD+-dependent deacetylases and ADP-ribosyltransferases governing gene expression, mitochondrial biogenesis, and stress responses. The poly(ADP-ribose) polymerases (PARPs) consume NAD+ to attach ADP-ribose chains to target proteins during the DNA damage response. CD38 is a cell-surface enzyme that hydrolyses NAD+ within immune signalling and intracellular calcium release.
Because all three draw on the same pool, competition for cellular NAD+ is itself a major research subject. PARP hyperactivation during DNA damage can drain NAD+ far enough to throttle sirtuin activity, tying DNA-repair stress to downstream metabolic and gene-expression consequences.
The Decline With Age
Tissue NAD+ falls steadily with age across many model organisms, rodents and humans included. Covarrubias, Perrone, Grozio, and Verdin reviewed that decline in Nature Reviews Molecular Cell Biology in 2020, gathering evidence that it is causally linked to numerous ageing-associated processes in research models, from mitochondrial dysfunction and cognitive decline to sarcopenia and metabolic disease. Lautrup and colleagues reviewed NAD+'s specific role in brain ageing and neurodegenerative disease research in Cell Metabolism in 2019.
Together these reviews make NAD+ repletion a major axis of ageing research. Both direct NAD+ administration and NAD+ precursors such as nicotinamide mononucleotide and nicotinamide riboside are studied here, each with its own pharmacokinetic and bioavailability profile in cell-culture and animal models.
Research Applications
NAD+ spans a wide range of research settings. Mitochondrial bioenergetics work uses NAD+ levels as a primary readout of redox state. Sirtuin-pathway research uses NAD+ supplementation to probe sirtuin-dependent transcriptional and metabolic effects. DNA damage and PARP-pathway research treats NAD+ depletion as a downstream signature of genotoxic stress. Ageing and longevity research uses NAD+ as both biomarker and intervention. And research on mitochondrial-derived peptides such as MOTS-C intersects with NAD+ through shared AMPK and mitochondrial-energy-sensing pathways.
Laboratory Handling
NAD+ comes as lyophilised powder, and because it is hygroscopic and sensitive to heat and light, storage matters more than usual. Keep it at -20°C before reconstitution, sealed and dark, away from moisture. Reconstitute with bacteriostatic water by running the diluent slowly down the inner wall of the vial and swirling gently. Store the reconstituted solution at 2-8°C, shield it from light, and use it promptly, since NAD+ is less stable in solution than the peptide compounds. The peptide storage guide covers general lyophilised-compound handling.
Sourcing in the UK
Peptura supplies research-grade NAD+ at 500 mg per vial with full third-party HPLC documentation published on the product page. Same-day UK dispatch on orders placed before 2pm GMT, free Royal Mail Tracked shipping over £45. For in-vitro laboratory research use only, not for human consumption.
Related Products
Disclaimer: This article is for research and educational purposes only. All information provided is not intended as medical advice. Peptura products are not for human consumption and are sold strictly for laboratory research use only.