NAD+: what the molecule is, how it is measured, how stable it is, and what a research-grade COA shows

What NAD+ is: a coenzyme, not a peptide#

NAD+ is the oxidized form of nicotinamide adenine dinucleotide, a coenzyme present in all living cells ^[1]. It is listed on the NAD+ product page alongside peptides, so it is worth being plain about the difference. A peptide is a chain of amino acids joined by amide bonds. NAD+ contains no amino acids. It is a dinucleotide: two nucleotides, one carrying nicotinamide and the other carrying adenine, joined through their phosphate groups. It is about an eighth of the mass of a 44-residue peptide such as tesamorelin, and it is handled, measured and degraded in different ways. Older names for the same molecule include diphosphopyridine nucleotide (DPN) and nadide, the title PubChem uses for its record (CID 5892) ^[1].

NAD+ chemistry: formula, molecular weight, CAS number and the NAD+/NADH pair#

NAD+ can be written in two ways, and the formula and mass depend on which is meant. As the cation, with a positive charge on the nicotinamide ring, the formula is C21H28N7O14P2, charge +1, average mass 664.44 and monoisotopic mass 664.116 ^[1]. As the neutral inner salt, with one phosphate deprotonated to balance the ring charge, the formula is C21H27N7O14P2 and the molecular weight is 663.4 g/mol; this is the form PubChem describes under CID 5892 and the basis of the figures on the product page. The CAS registry number is 53-84-9 under either description ^[1]. A mass spectrometer reading near 664 is seeing the protonated cation; 663.4 is the same molecule counted as a neutral salt.

NAD+ is one half of a redox pair. When it accepts two electrons and a proton at the nicotinamide ring it becomes NADH, the reduced form. The constant interconversion of the two forms is how NAD+ carries electrons from the breakdown of nutrients to the mitochondrial reactions that make ATP ^[2]. A vial labeled NAD+ should contain the oxidized form; NADH is a different compound with a different absorbance spectrum, and the two are told apart analytically.

NAD+ is also distinct from its precursors. Nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR) are smaller molecules that cells convert into NAD+, and most human studies described as NAD+ research were in fact studies of one of these precursors taken by mouth ^[2]. None of them is NAD+, and data on one cannot be read across to the others.

The enzyme families that consume NAD+: sirtuins, PARPs and CD38#

In its redox role NAD+ is regenerated, not used up. A second group of enzymes consumes it, cleaving the bond between nicotinamide and the rest of the molecule and releasing nicotinamide as a by-product. The 2021 review by Covarrubias and colleagues in Nature Reviews Molecular Cell Biology groups these NAD+-consuming enzymes into three families: sirtuins, which remove acyl groups from proteins; poly(ADP-ribose) polymerases (PARPs), which attach ADP-ribose units to proteins during DNA repair; and the CD38 and CD157 glycohydrolases, which make signaling molecules from NAD+ ^[2]. The same review states that NAD+ levels decline with age in multiple model organisms, including rodents and humans, and lists how NAD+ levels are regulated, how best to restore them and whether doing so is safe or useful in aging humans as open questions ^[2].

Camacho-Pereira and colleagues reported in Cell Metabolism in 2016 that the expression and activity of CD38 increase with age in mouse tissues, that CD38 was required for the age-related decline in NAD+ they measured in those tissues, and that CD38 was the main enzyme degrading NMN in vivo in their mouse experiments ^[3]. This is animal and tissue work; it is cited because it explains why extracellular NAD+ and NMN are short-lived in biological fluids, a point that returns in the pharmacokinetic study below.

Stability of NAD+ in solution and as a solid#

The foundational stability work is Lowry, Passonneau and Rock's 1961 paper in the Journal of Biological Chemistry. They examined how stable the oxidized and reduced pyridine nucleotides are under different conditions and found a mirror-image pattern: the oxidized forms (NAD+ and NADP+) are stable in acid but destroyed by alkali, while the reduced forms (NADH and NADPH) are stable in alkali but destroyed by acid ^[4]. That asymmetry is still the basis of how laboratories extract one form without the other, and it is the first thing to know about a NAD+ solution: its pH decides its fate.

A 2024 study in Molecules by Wolfe and colleagues followed nicotinamide cofactors in three common 50 mM buffers at pH 8.5 for 43 days at 19 °C and 25 °C, using UV-visible spectroscopy. In Tris buffer the NAD+ absorbance at 260 nm fell only about 4%; in HEPES, a 2 mM NAD+ solution degraded almost entirely; in sodium phosphate it degraded at a rate the authors described as similar to NADH, and they suggested phosphate may catalyze the breakdown ^[5]. Two solutions of the same NAD+ at the same pH and temperature can therefore behave very differently depending on the buffer salt.

Heat accelerates the same chemistry: Hachisuka, Sato and Atomi noted in 2017 that NAD+ is susceptible to thermal degradation at high temperatures, so that heat-loving microorganisms need mechanisms to maintain their NAD+ pool ^[6]. The non-enzymatic cleavage runs across the bond between nicotinamide and ribose, giving nicotinamide and ADP-ribose, the same products the enzyme CD38 makes; the metabolite pattern in the human infusion study below is consistent with that breakdown ^[7].

Biological samples are a harsher case because enzymes are present. Trammell and Brenner wrote in 2013 that methods which fail to inactivate enzymes at cell lysis are flawed, because cellular NAD+ can fall to about 1% of its expected value during autolysis; their own method extracts cells into 75% ethanol preheated to 80 °C to stop that ^[8]. Matsuyama and colleagues stated in 2023 that NAD+ in whole blood is unstable at room temperature and that NMN degraded by almost 50% after two days of storage, attributing the loss mainly to CD38 activity ^[9].

Two gaps should be stated. First, we found no primary study of light exposure on NAD+ solutions, so this page makes no claim about it. Second, the published stability work is on solutions and biological samples; stability data for lyophilized NAD+ as a dry solid come from manufacturer specifications rather than peer-reviewed studies and are not cited here. Hydrolysis needs water, so a dry, cold, closed vial removes the main route of loss, and the figures that matter are the purity and content on the certificate for the lot you hold. Our guide to storing lyophilized peptides covers the storage principles that apply to lyophilized reagents in general.

How laboratories measure NAD+: HPLC-UV, LC-MS and enzymatic cycling#

• HPLC with UV detection. NAD+ absorbs strongly near 260 nm because of its adenine ring, and NADH has an additional band at 340 nm from the reduced nicotinamide ring, which is how the two are distinguished spectroscopically ^[5]. HPLC-UV separates NAD+ from its breakdown products and reports purity as the area of the main peak against the total. Trammell and Brenner caution that in complex biological mixtures a single UV peak may contain more than one compound, so HPLC-UV is most reliable on a purified material, which is exactly the case for a research-grade lot ^[8].
• Liquid chromatography with mass spectrometry (LC-MS or LC-MS/MS). Mass spectrometry confirms identity by mass. Matsuyama and colleagues quantified NAD+ in blood by LC-MS/MS using the NAD+ transition m/z 664.1 to 136.1 and a deuterated NAD+ internal standard, with calibration linear from 0.25 to 200 µM ^[9]. Grant and colleagues measured plasma and urine NAD+ and its metabolites by LC-MS/MS on a triple-quadrupole instrument ^[7]. Trammell and Brenner used a 13C-labeled yeast extract as an internal standard so that matrix effects cancel out, with limits of quantification mostly below 100 femtomoles ^[8]. The 664 parent ion and the 136 fragment (protonated adenine) are the signature a COA mass spectrum should show.
• Enzymatic cycling assays. These use a dehydrogenase to shuttle NAD+ back and forth between its oxidized and reduced forms, so that each molecule of NAD+ generates many molecules of a colored or fluorescent product. Brunnbauer and colleagues reported in 2018 an alcohol-dehydrogenase cycling assay for NAD+ in human plasma with sensitivity reaching the low nanomolar range ^[10]. Cycling assays measure total NAD+ activity rather than identity, so they are not a substitute for mass spectrometry on a COA.

Human studies of NAD+ itself: what was measured#

Most human NAD+ research has studied oral precursors, chiefly NR and NMN, and those studies are about those molecules ^[2]. Published human data on NAD+ itself are limited to pharmacokinetic work, and the most cited study is a 2019 pilot by Grant and colleagues in Frontiers in Aging Neuroscience. Eleven men aged 30 to 55 took part; eight received a six-hour intravenous infusion of NAD+ and three received saline. The investigators measured NAD+, nicotinamide, methylnicotinamide, ADP-ribose and NMN in plasma and urine by LC-MS/MS. Plasma NAD+ did not rise above baseline for the first two hours; the authors describe it as rapidly and completely removed from the plasma for at least that period. It then rose to about four times baseline by the end of the infusion, and urinary NAD+ and methylnicotinamide were raised at six hours while urinary nicotinamide was not. The authors wrote that the metabolite profile is consistent with NAD+ glycohydrolase and pyrophosphatase activity, reported no adverse events in either group, and noted that the small sample limits what can be concluded ^[7].

That is the extent of what this page can report about NAD+ in people: one pilot pharmacokinetic study in eleven men, describing where the molecule went and how quickly. It is not an outcome study, and no outcome study of NAD+ itself is cited here.

Regulatory status: not an approved drug, and the NMN record#

NAD+ is not an FDA-approved drug for any condition, and no NAD+ product has a prescribing label. The clearest regulatory record in this area concerns the precursor NMN, not NAD+, and it is worth stating accurately because the two are often confused.

On November 4, 2022, FDA's Office of Dietary Supplement Programs wrote to a notifier that beta-nicotinamide mononucleotide "is excluded from the definition of a dietary supplement," on the ground that NMN had been authorized for investigation as a new drug and substantial clinical investigations had been made public before it was lawfully marketed as a supplement; the letter stated that this meant NMN could not be marketed as or in a dietary supplement ^[11]. On December 2, 2025, the same office wrote that FDA had changed its reading of the relevant clause after a citizen petition, that "NMN is not excluded from the dietary supplement definition," and that it was setting aside the 2022 letter ^[12]. Both letters concern NMN as a dietary ingredient. Neither concerns NAD+, and neither bears on research-grade material, which is not sold as a food, supplement or drug.

We found no listing of NAD+ on the current WADA Prohibited List under its own name, and this page makes no statement about anti-doping status beyond that.

What the Renuvia NAD+ COA shows: lot RN-2610-NAD#

Renuvia's NAD+ is sold as a 1,000 mg vial (SKU REN-NAD-1000). The October 2026 lot, RN-2610-NAD, was tested by Freedom Diagnostics Testing on October 31, 2026. The published certificate reports HPLC-UV purity of 99.31%, LC-MS identity confirmed, and a measured content of 1,012.60 mg, which is 101.3% of label; the laboratory report lists the sample as the "Black Cap" vial ^[13]. The certificate is in the COA library; no third-party verification link is attached to this lot. Our guide to HPLC and mass spectrometry explains the two methods on the report.

When you read any NAD+ certificate, check these points, which follow from the chemistry above. Because NAD+ is not a peptide, the report will not show amino acid analysis or peptide content.

1. The identity result should correspond to NAD+, with a mass spectrum showing the protonated molecule near m/z 664 and, where fragments are reported, the adenine fragment at m/z 136 ^[9]. A strong absorbance at 340 nm would point to NADH, a different compound ^[5].
2. The purity should be an HPLC figure, not an inference from appearance. Because NAD+ breaks down to nicotinamide and ADP-ribose, a certificate on an aged or poorly stored lot would show those as separate peaks; a clean chromatogram is itself evidence about storage.
3. Content in milligrams should be stated separately from purity. For a 1,000 mg vial, the content figure is the number to compare against the label; purity tells you how much of that mass is NAD+. Our guide to purity report misreadings explains the difference.
4. The lot number on the certificate should match the vial, the laboratory should be named, and the test date should be recent relative to when the lot was packed. The guide to verifying a Certificate of Analysis covers how to check the issuing laboratory.