NAD+

Category: Coenzymes · Last updated 2026-05-18

NAD+ (nicotinamide adenine dinucleotide, oxidized form) is an endogenous coenzyme found in every living cell. It transfers electrons in glycolysis, the citric-acid cycle, and oxidative phosphorylation, and is the obligate substrate of sirtuins and poly-ADP-ribose polymerases (PARPs). The lyophilized research-grade powder sold here is the same chemical species that appears endogenously; it is supplied for in-vitro research only.

Peppudex card: see the mechanism + evidence-grade summary at [Peppudex / NAD+](https://peppudex.com/peptides/nad-plus).

Overview

NAD+ was first isolated by Arthur Harden in 1906 as a "co-ferment" that accelerated yeast fermentation. The two-nucleotide dinucleotide structure (nicotinamide-ribose-phosphate-phosphate-ribose-adenine) was elucidated by Otto Warburg in the 1930s. Cellular NAD+ pools cycle between oxidized (NAD+) and reduced (NADH) forms, with the ratio driving redox state across compartments.

The compound is hygroscopic, light-sensitive, and degrades in solution faster than most peptides. Lyophilized vials retain activity at 2–8 °C for months; reconstituted solutions should be used or aliquot-frozen within days.

Mechanism

NAD+ functions in three distinct biochemical roles:

Electron transfer. Accepts hydride from substrates in dehydrogenase reactions, generating NADH for the electron-transport chain.
Sirtuin substrate. Class III lysine deacylases (SIRT1–SIRT7) consume NAD+ stoichiometrically to remove acyl groups from target proteins; SIRT1 deacetylates PGC-1α, p53, FOXO3, and other regulators of metabolism and stress response.
PARP / CD38 substrate. Poly-ADP-ribose polymerases consume NAD+ during DNA-damage response. CD38 hydrolyzes NAD+ on cell surfaces and is a major contributor to age-related NAD+ decline.

NAD+ does not "bind a receptor" in the classical pharmacological sense. Direct administration of full-length NAD+ at the cell-membrane scale is debated; most translational interest centers on NAD+ precursors (nicotinamide riboside, nicotinamide mononucleotide) that cross the plasma membrane more efficiently.

See: Sirtuin_activation, Mitochondrial_function, DNA_repair.

Evidence

The peer-reviewed literature on NAD+ biology is enormous and dates to the 1930s. The aging-biology framing is more recent:

NAD+ decline in aging and disease was reviewed by Imai and Guarente (Trends Cell Biol 2014; PMID 24786309).
The contemporary biology of NAD+ metabolism — NAMPT, NMNAT, NRK enzymes, sirtuins, PARPs — was synthesized by Yoshino, Baur, and Imai (Cell Metab 2018; PMID 29249689).
An accessible mechanism overview is provided by Johnson and Imai (F1000Research 2018; PMID 29744033).

Human clinical trials primarily test NAD+ precursors (NR and NMN), not exogenous NAD+ itself. ClinicalTrials.gov lists multiple NMN and NR trials in cognitive, metabolic, and longevity endpoints; few have completed Phase 3.

Dosing literature

Animal NAD+ administration in published preclinical literature spans wide ranges (single-digit to hundreds of mg/kg) and depends entirely on route, formulation, and model. No human dose is recommended by this wiki. Community-reported research protocols for the lyophilized salt vary widely and have no peer-reviewed endorsement. See Reconstitution for vial-prep math.

Storage

Lyophilized: 2–8 °C protected from light, stable 12+ months. Reconstituted: 2–8 °C protected from light, aliquot-freeze recommended for storage beyond 7 days. Avoid repeat freeze-thaw of the reconstituted salt.

Regulatory status

United States. Not FDA-approved as a drug. The NAD+ precursors nicotinamide riboside (NR) and nicotinamide mononumeotide (NMN) have been the subject of FDA enforcement actions in 2022–2024 regarding their classification as dietary supplements vs investigational drugs. The exogenous NAD+ salt remains a chemistry reagent under standard laboratory-use framing.
WADA. Not currently on the prohibited list.

References

Yoshino J, Baur JA, Imai S. "NAD+ Intermediates: The Biology and Therapeutic Potential of NMN and NR." Cell Metab. 2018;27(3):513-528. PMID 29249689.
Imai S, Guarente L. "NAD+ and sirtuins in aging and disease." Trends Cell Biol. 2014;24(8):464-71. PMID 24786309.
Johnson S, Imai S. "NAD+ biosynthesis, aging, and disease." F1000Res. 2018;7:132. PMID 29744033.

Research framing only. Peppu Wiki documents the published research literature surrounding peptide compounds. Articles describe in-vitro and animal-model evidence, regulatory status, and community-reported protocols. Nothing on this site is medical advice, a recommendation for human use, or a substitute for consultation with a qualified clinician. All compounds discussed are research-use only. Citations should be verified at the source before relying on any quantitative claim.

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