NAD+ (Injectable) — Research Product Overview

**Disclaimer:** This product overview is provided strictly for in-vitro and preclinical research use. [NAD+](/catalog/nad-plus) is not approved by the FDA as a drug, and nothing in this document constitutes medical advice or a recommendation for human administration. Materials are sold to qualified research professionals for laboratory investigation only.

Important Classification Note

NAD+ is a small-molecule dinucleotide coenzyme, not a peptide. It is included in the Viking Labs research catalog because of its central role in the longevity- and metabolism-research literature alongside peptide compounds, but the chemistry, handling, and analytical specifications differ from those of peptide products. Researchers should not extrapolate peptide-handling protocols (e.g., bacteriostatic water reconstitution norms) to NAD+ without consulting NAD+-specific stability data.

For background on related research compounds see NAD vs NMN vs NR and the sirtuin-NAD axis, as well as the peptides longevity research 2026 overview situating NAD+ within the broader longevity tool-compound landscape.

Overview

Nicotinamide adenine dinucleotide (NAD+) is a coenzyme present in every living cell, participating in over 500 enzymatic reactions and serving as both an electron carrier in central metabolism and a consumed substrate for the sirtuin, PARP, and CD38/CD157 enzyme families. The discovery in the early 2000s that tissue NAD+ levels decline with age — and that this decline contributes to mitochondrial dysfunction, impaired DNA repair, and reduced sirtuin-mediated stress responses — established NAD+ augmentation as a major axis of aging research. Direct injectable NAD+ is studied in preclinical models alongside the more pharmacokinetically tractable precursors NMN and NR.

Chemical Identity

• Chemical name: β-Nicotinamide adenine dinucleotide
• Synonyms: NAD+, NAD, DPN, Coenzyme I
• CAS number: 53-84-9
• Molecular formula: C21H27N7O14P2
• Molecular weight: 663.43 Da (free acid); commonly supplied as the disodium salt (~707 Da)
• Structure: dinucleotide of nicotinamide riboside and adenosine joined through a pyrophosphate bridge
• Charge: polyanionic at physiological pH (multiple phosphate negative charges plus pyridinium positive on the nicotinamide ring)

NAD+ exists in equilibrium with its reduced form NADH; the ratio is a critical determinant of cellular redox state. The oxidized form NAD+ is what is typically supplied as a research reagent.

Mechanism of Action (Summary)

1. Redox coenzyme — accepts electrons in glycolysis (GAPDH step) and in three TCA-cycle dehydrogenases, generating NADH that drives oxidative phosphorylation.
2. Sirtuin substrate — SIRT1–7 are NAD+-dependent protein deacylases regulating gene expression, mitochondrial biogenesis (via PGC-1α), and DNA repair.
3. PARP substrate — PARP1 consumes NAD+ during DNA-damage repair, transferring ADP-ribose to target proteins.
4. CD38/CD157 substrate — these ectoenzymes cleave NAD+ to generate cyclic ADP-ribose, a Ca²⁺-mobilizing second messenger.
5. Replenishment of declining tissue pools — exogenous NAD+ or its precursors restore intracellular NAD+ in aged cells.

A frequently raised question is whether intact NAD+ crosses the plasma membrane. Direct cellular uptake of intact NAD+ is limited; much of the in-vivo activity following parenteral NAD+ administration is thought to arise from extracellular degradation to nicotinamide and nicotinamide riboside, which are then internalized and re-synthesized into intracellular NAD+ via salvage pathways.

Preclinical Research Summary

NAD+ research spans four decades. Imai and Guarente established the NAD+-sirtuin link in the early 2000s. Yoshino, Baur, and Imai's 2018 *Cell Metabolism* review systematized the precursor pharmacology. NMN and NR have been studied extensively in rodent models of metabolic dysfunction, neurodegeneration, and accelerated aging, with documented improvements in mitochondrial function, insulin sensitivity, vascular function, and cognitive performance in aged mice. Direct injectable NAD+ has been studied less systematically than the precursors, with most controlled work in cell culture and isolated tissue preparations rather than whole-animal models, but is widely used as the analytical standard and substrate in enzymatic assays.

Comparator Peptides and Molecules

NAD+ sits at the center of a small constellation of related research compounds, each with distinct pharmacology. NMN (nicotinamide mononucleotide) is a single-step precursor — it lies one enzymatic step (NMNAT-mediated adenylylation) upstream of NAD+ and has demonstrated good oral bioavailability in mouse models (Mills et al. 2016). NR (nicotinamide riboside) is a two-step precursor that enters cells via dedicated nucleoside transporters and is converted to NMN by NRK1/NRK2 kinases; NR has the most favorable human pharmacokinetic profile and has been advanced through multiple clinical trials (Trammell et al. 2016, *Nat Commun*). Nicotinamide (Nam) is the simplest precursor, abundant in the diet, but its pharmacology in NAD+-augmentation contexts is complicated by feedback inhibition of sirtuins. Niacin (nicotinic acid) raises NAD+ via the Preiss-Handler pathway but produces vasodilatory flushing at therapeutic doses. The detailed pharmacological comparison is treated in NAD vs NMN vs NR.

Beyond direct NAD+ pharmacology, the sirtuin-NAD axis intersects multiple longevity research compounds. Resveratrol and other polyphenols allosterically activate SIRT1 with NAD+ co-substrate dependence. CD38 inhibitors (78c, apigenin) raise NAD+ by reducing its degradation rather than supplying precursors. Among peptide and biological-molecule comparators, Epitalon targets telomerase preservation, FOXO4-DRI targets senescent-cell clearance, and the regenerative peptides BPC-157, TB-500, and GHK-Cu target tissue-repair pathways that intersect NAD+ via PARP and sirtuin activity. Researchers may also consider the mTOR pathway peptides literature for adjacent metabolic axes.

Deeper Preclinical Breakdown

Verdin 2015 (*Science* 350, PMID 26785480, "NAD+ in aging, metabolism, and neurodegeneration") consolidated two decades of NAD+ biology into the conceptual framework still in use. The review established that tissue NAD+ levels decline with age across multiple species, that this decline contributes to mitochondrial dysfunction and impaired DNA repair, and that augmentation strategies (precursor supplementation, CD38 inhibition, NAMPT activation) can restore NAD+ levels and rescue aged-tissue phenotypes. This paper is the most-cited NAD+/aging reference and remains the standard introduction.

Yoshino, Baur, and Imai 2018 (*Cell Metabolism* 27, PMID 29249689, "NAD+ Intermediates: The Biology and Therapeutic Potential of NMN and NR") systematized precursor pharmacology, comparing NMN and NR head-to-head across pharmacokinetics, tissue distribution, cellular uptake mechanisms, and indication-specific efficacy. This review remains the most-cited single source for newcomers to NAD+ precursor research and is referenced extensively in subsequent translational work.

Mills et al. 2016 (*Cell Metab* 24, PMID 28068222) demonstrated that long-term oral NMN administration (100 mg/kg/day or 300 mg/kg/day for 12 months) mitigated multiple age-associated physiological declines in C57BL/6 mice. Endpoints included improved insulin sensitivity, improved bone density, improved mitochondrial function in skeletal muscle, and improved retinal function. Tissue NAD+ levels rose dose-dependently. The study was prospective and well-controlled, and remains the strongest single demonstration of in-vivo benefit from NAD+ precursor supplementation in healthy aging mice. Limitations include the use of healthy mice rather than aged-disease models and the open question of whether NMN is converted extracellularly to NR before cellular uptake.

Trammell et al. 2016 (*Nat Commun* 7, PMID 27721479) characterized the unique oral bioavailability of NR in mice and humans, showing rapid conversion to NAD+ in liver, muscle, and brown adipose tissue without flushing or other niacin-class side effects. This study established NR as the leading clinical-stage NAD+ precursor and supports a body of subsequent human pilot trials. The principal limitation across the NAD+ precursor literature is the lack of long-term clinical outcome data — the longest controlled human studies are months, not years.

Formulation Considerations

Direct injectable NAD+ is supplied as a white-to-pale-yellow lyophilized powder, typically 100 mg, 500 mg, or 1 g per vial, most commonly as the disodium salt. Unlike peptide products that reconstitute uneventfully in bacteriostatic water, NAD+ is more chemically labile: it hydrolyzes at acidic pH, degrades at high temperatures, and must be stored in mildly alkaline buffer (pH 7.5–9.0) for best stability. Reconstitution at neutral-to-slightly-alkaline pH in sterile water or PBS is standard. Working concentrations of 1–10 mM are typical for enzymatic assays.

Common impurities visible on a quality COA include nicotinamide (the principal degradation product), ADP-ribose (from non-enzymatic hydrolysis of the pyrophosphate bridge), and NADH (the reduced form). The A260/A340 ratio is the simplest in-house check of oxidation state — pure NAD+ has minimal absorbance at 340 nm, while NADH has a strong 340 nm peak. Light protection (amber vials or foil wrap) is recommended for long-term storage. The reagent is hygroscopic and should remain desiccated until use. Note that NAD+ is not interchangeable with peptide protocols — consult NAD+-specific stability data rather than extrapolating from peptide handling. The peptide drug delivery 2026 overview discusses the broader challenges of translating biologically labile compounds, many of which apply to NAD+.

Research-Context Dosing Ranges

In-vitro: 1–10 mM in enzymatic assays for sirtuin and PARP activity; 100 µM to 1 mM for cell-culture NAD+ rescue experiments. Rodent in-vivo: NMN at 100–500 mg/kg/day oral; NR at 100–1000 mg/kg/day oral; direct injectable NAD+ has been used IP at 100–500 mg/kg in less-validated protocols. Human clinical trials of NMN and NR have used 250–1000 mg daily orally. No human dosing recommendation is implied for any form of NAD+ or its precursors.

Common Research Applications

• Enzymatic assays for sirtuin deacetylase activity (NAD+ as substrate)
• PARP activity assays
• Mitochondrial respiration studies (Seahorse-type assays measuring NAD+/NADH-coupled flux)
• Cell-culture NAD+ rescue experiments in aged or stress-induced primary cells
• Comparative pharmacology versus NMN and NR — see NAD vs NMN vs NR
• Sirtuin-axis combination studies — see the sirtuin-NAD axis

Handling, Reconstitution, and Storage

• Form supplied: white-to-pale-yellow lyophilized powder, typically 100 mg, 500 mg, or 1 g per vial; commonly supplied as the disodium salt
• Reconstitution: sterile water or buffered saline at neutral pH (7.0–7.4); NAD+ is highly water-soluble (~50 mg/mL achievable)
• pH stability: NAD+ is most stable in mildly alkaline solutions (pH 7.5–9.0); it hydrolyzes at acidic pH and degrades at high temperatures
• Working concentration: 1–10 mM stock solutions are typical for enzymatic assays
• Lyophilized stability: ≥24 months at -20 °C, desiccated and protected from light
• Reconstituted stability: at -20 °C or -80 °C, several months in aliquots; at 2–8 °C, days rather than weeks; freshly prepared solutions are preferred for kinetic enzymatic measurements
• Avoid: acidic buffers (rapid hydrolysis), heat, repeated freeze-thaw, and long-term storage of reconstituted material at room temperature
• Light sensitivity: moderate; store in amber vials or wrapped in foil

NAD+ is more chemically labile than most peptides; researchers accustomed to peptide-stability timeframes should plan accordingly.

Lab Specifications

• [HPLC](/research/glossary#hplc) purity target: ≥98.0% by RP-HPLC at 260 nm (NAD+ has a characteristic absorbance maximum at 260 nm with ε ~17,800 M⁻¹cm⁻¹)
• Identity confirmation: ESI-MS [M-H]⁻ at m/z 662.1; UV ratio A260/A340 distinguishes NAD+ (oxidized, no 340 nm absorbance) from NADH (reduced, A340 peak)
• NADH content: <2% (oxidized NAD+ should be predominantly the NAD+ form)
• Water content: <8% by Karl Fischer (lyophilized form)
• Endotoxin: <1 EU/mg for cell-culture grade
• Heavy metals: <10 ppm
• Residual solvents: within ICH Q3C limits

The 260 nm absorbance and the A260/A340 ratio are particularly useful in-house confirmations of NAD+ identity and oxidation state. See understanding peptide purity for general analytical concepts that translate to small-molecule research products.

Cross-References

Related Viking Labs research:

• NAD vs NMN vs NR
• Sirtuin-NAD axis
• Product overview: Epitalon
• Product overview: FOXO4-DRI
• Peptides longevity research 2026
• mTOR pathway peptides
• Peptide drug delivery 2026

Summary

NAD+ is a foundational research compound at the intersection of metabolism and aging biology, distinguished from the peptide products in this catalog by its small-molecule dinucleotide chemistry. Researchers working with NAD+ should plan around its chemical lability, its sensitivity to acid and heat, and the open question of whether intact NAD+ versus its degradation precursors accounts for in-vivo activity. The much larger and more rigorous body of pharmacological work on NMN and NR should be consulted when designing translational hypotheses.

*This document is provided for research and educational purposes only. Viking Labs does not sell products intended for human consumption.*