NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every living cell, essential for hundreds of metabolic reactions. It exists in two forms: the oxidized form (NAD+) and the reduced form (NADH), which together participate in redox reactions that drive cellular energy production. The molecular formula is C21H27N7O14P2 with a molecular weight of 663.43 Da.
NAD+ was first described by Arthur Harden and William John Young in 1906 during yeast fermentation studies. Since then, it has been recognized as one of the most important molecules in biology — serving as a substrate for sirtuins (SIRT1-7), poly(ADP-ribose) polymerases (PARPs), and CD38/CD157 ectoenzymes, all of which regulate critical cellular processes including DNA repair, gene expression, and calcium signaling.
Why Researchers Study NAD+
NAD+ has become one of the most actively studied molecules in aging and metabolic research due to its central role in cellular function:
Cellular energy metabolism: NAD+ is required for glycolysis, the TCA cycle, and oxidative phosphorylation. It accepts and donates electrons through the NAD+/NADH redox pair, directly coupling nutrient oxidation to ATP production in mitochondria.
Sirtuin activation: Sirtuins (SIRT1-7) are NAD+-dependent deacylases that regulate metabolic homeostasis, stress responses, circadian rhythm, and epigenetic modification. NAD+ availability directly determines sirtuin activity, linking metabolic state to gene regulation.
DNA repair: PARP enzymes consume NAD+ as a substrate to synthesize poly(ADP-ribose) chains that recruit DNA repair machinery to sites of genomic damage. Under conditions of extensive DNA damage, PARP hyperactivation can deplete cellular NAD+ pools.
Age-related decline: Research has documented that NAD+ levels decline significantly with age across multiple tissues. This decline correlates with reduced mitochondrial function, increased DNA damage accumulation, and dysregulated inflammatory signaling — collectively termed the "NAD+ world" hypothesis.
Neurodegenerative disease models: NAD+ depletion has been observed in experimental models of Alzheimer's, Parkinson's, and ALS. Research explores whether maintaining NAD+ levels can preserve axonal integrity and neuronal bioenergetics under stress conditions.
How to Evaluate NAD+ Purity
NAD+ quality verification requires attention to both chemical purity and the correct oxidation state:
HPLC purity: Look for 98% or higher purity confirmed by reversed-phase HPLC. This separates NAD+ from potential contaminants including nicotinamide, ADP-ribose, and degradation products.
Oxidation state verification: The COA should confirm the product is primarily in the oxidized NAD+ form rather than the reduced NADH form. UV spectrophotometry can distinguish between the two — NAD+ absorbs at 260nm while NADH has an additional absorption peak at 340nm.
Mass spectrometry: ESI-MS should confirm the molecular weight of 663.43 Da, verifying the correct dinucleotide structure with both nicotinamide and adenine moieties intact.
Moisture content: NAD+ is highly hygroscopic. Karl Fischer titration or loss-on-drying analysis should confirm moisture content is within acceptable limits, as excess moisture accelerates degradation.
Batch-specific documentation: Every COA should reference a specific lot number. Generic or undated certificates suggest the supplier may not test each production batch individually.
How to Choose an NAD+ Supplier
When selecting a supplier for research-grade NAD+, evaluate these factors:
Third-party testing: COA documents should come from an independent analytical laboratory, not the manufacturer's in-house facility. Independent verification eliminates conflicts of interest in purity and identity reporting.
Proper lyophilization: NAD+ should be supplied as a white to off-white lyophilized powder. Discoloration (yellow or brown) may indicate degradation or oxidative damage during manufacturing.
Cold-chain shipping: NAD+ is thermally sensitive. Reputable suppliers ship with cold packs and insulated packaging to prevent degradation during transit, particularly during warmer months.
Appropriate sizing: Suppliers should offer multiple vial sizes to accommodate different research scales. This allows researchers to minimize waste from degradation of reconstituted material that cannot be used quickly enough.
Research-use labeling: Products should be clearly labeled "For Research Use Only — Not for Human Consumption." Suppliers marketing NAD+ for personal use operate outside the research-supply framework.
US-based operations: Domestic suppliers provide faster shipping, better cold-chain integrity, and more straightforward customer service for US-based research institutions.
Where to Buy NAD+
PeptidesATX offers research-grade NAD+ with the purity documentation and cold-chain shipping that metabolic research demands:
Every PeptidesATX product ships with a batch-specific Certificate of Analysis from a third-party laboratory, verifying purity by HPLC and identity by mass spectrometry. All products ship from Austin, TX with cold-chain packaging.
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Browse our NAD+ products with third-party tested purity, batch-specific COA, and fast shipping from Austin, TX.
NAD+ for laboratory research can be purchased from specialized suppliers such as PeptidesATX. Verify that the supplier provides third-party Certificates of Analysis (COA), guarantees 98%+ purity, and clearly labels products for research use only.
What is NAD+ and why is it studied?
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme present in all living cells that plays a central role in cellular metabolism, energy production, DNA repair, and sirtuin activation. Research focuses on NAD+ decline with aging and its implications for metabolic, neurodegenerative, and cardiovascular disease models.
What purity should research-grade NAD+ have?
Research-grade NAD+ should have a minimum of 98% purity verified by HPLC. The COA should also include mass spectrometry confirmation of the correct molecular weight (663.43 Da) and verification of the oxidized form (NAD+) versus the reduced form (NADH).
How should NAD+ be stored after purchase?
Store lyophilized NAD+ at -20°C or below, protected from light and moisture. NAD+ is hygroscopic and sensitive to degradation in solution, so reconstitute only the amount needed for immediate use. Once in solution, store at 2-8°C and use within 1-2 weeks.
What sizes does NAD+ come in?
PeptidesATX offers NAD+ in 500mg and 1000mg vial sizes as a lyophilized powder. The 500mg size is suitable for smaller-scale experiments, while the 1000mg size is more economical for ongoing research programs requiring larger quantities.
Disclaimer: All products sold by PeptidesATX are intended for laboratory and research use only. They are not intended for human consumption, veterinary use, or any clinical application. By purchasing, the buyer acknowledges that the products will be used solely for in-vitro research and agrees to comply with all applicable laws and regulations regarding the handling and use of research chemicals.