Where to Buy NAD+ in 2026: Sizes, Purity Reports and Verification

NAD+ (nicotinamide adenine dinucleotide, INN nadide) is a dinucleotide, not a peptide. Chemical suppliers sell it in several salt forms, so buying it correctly means reading the listing: which form, which mass figure, and which report. This guide covers the chemistry, the Pepta Labs sizes, report verification, storage and US regulatory status.

What Is NAD+?

NAD+ consists of two nucleotides, adenosine monophosphate and nicotinamide mononucleotide, joined through their phosphates by a pyrophosphate bridge, with both ribose units in the beta-D configuration. The plus sign refers to the positive charge on the pyridinium nitrogen of the nicotinamide ring, which distinguishes NAD+ from NADH, the two-electron reduced form (C21H29N7O14P2, 665.4 g/mol). Registry numbers for the rest of the catalog are collected in the CAS number and molecular weight table.

Free acid or sodium salt?

CAS 53-84-9 identifies NAD+ as the free acid: one phosphate proton is lost to balance the pyridinium charge, so the solid is an inner salt (a zwitterion) with the neutral formula C21H27N7O14P2. Suppliers also sell salt forms under their own registry numbers, the sodium salt (CAS 20111-18-6, C21H26N7NaO14P2, 685.4 g/mol) and the lithium salt (CAS 64417-72-7, C21H26LiN7O14P2, 669.4 g/mol), plus hydrates of each. Gram for gram, the sodium salt contains about 3% fewer moles of NAD+ than the free acid, and a report quoting 685.4 g/mol describes a different solid from one quoting 663.4 g/mol. The Pepta Labs listing quotes the free-acid CAS number, formula and molecular weight; the form supplied is stated on the analytical report.

Monoisotopic versus average mass

Two mass figures appear in NAD+ documentation and both are correct. The average molecular weight, 663.43 g/mol, is calculated from average atomic masses and is the figure for weighing and molar calculations. The monoisotopic mass, 663.109 Da, uses the most abundant isotope of each element and is what a mass spectrometer resolves for a molecule of this size, so a spectrum shows [M+H]+ near m/z 664.12 or [M-H]- near m/z 662.10, never a peak at 663.43. The 0.3 Da gap is a convention, not an error. The expected mass table applies the same convention across the catalog.

How Pepta Labs Lists NAD+

Both sizes are the same material in a sealed glass vial and sit in the thymic category next to thymosin alpha-1, a catalog grouping rather than a chemical one. The product page shows the reported HPLC purity for the sourced production run. Purity is measured by reversed-phase HPLC and identity by mass spectrometry, both reported by an independent laboratory commissioned through a cooperative purchasing group; Pepta Labs does not test in-house. The analytical report (COA) is available by email on request. Free US shipping, and most orders ship the next business day. The testing arrangement is described on the Testing and Documentation page.

How to Verify an NAD+ Listing

What an HPLC report shows and does not show

A reversed-phase HPLC chromatogram shows how the UV-absorbing material in the sample separates on the column; purity is the main-peak area as a percentage of total peak area at the detection wavelength, typically 260 nm for NAD+, where the adenine ring absorbs. Area percent does not show water content (NAD+ is hygroscopic), inorganic salts, residual solvents or the fill weight of the vial, and it does not show the counter-ion: the free acid and the sodium salt give identical chromatograms.

What a mass spectrometry report shows

Electrospray mass spectrometry confirms identity by mass. An observed value within about 0.02 Da of the calculated ion on a high-resolution instrument, or within 0.5 Da on a unit-resolution instrument, is consistent with C21H27N7O14P2. MS does not measure purity or quantity, and a sodium adduct, [M+Na]+, appears from the free acid as readily as from a sodium salt, so the salt form is read from the form stated on the report, not from adduct peaks.

Production-run report versus lot-specific COA

The report Pepta Labs supplies covers the sourced production run, the batch from which the vials were filled; it may name the purchasing group or the source, rather than Pepta Labs, as the client. A lot-specific COA is the manufacturer's document for a numbered lot. Either way, its lot or run reference should match the vial label and its molecular weight should match the form on the label. A generic certificate with no reference at all is the thing to reject. The COA verification guide and the HPLC versus mass spectrometry article walk through each field.

Storage and Shipping

• NAD+ ships as a lyophilized powder at ambient temperature; a few days in transit at room temperature is standard for a dry, sealed solid.
• Refrigerate at 2-8 C on arrival. For storage beyond a few months, keep the sealed vial at -20 C.
• Protect from moisture and light: NAD+ is hygroscopic and discolors with prolonged exposure to humidity and light. Let a cold vial reach room temperature before opening so that condensation does not form on the powder, and keep opened vials in a desiccator.

US Regulatory Status

NAD+ is a common biochemical reagent, and Pepta Labs sells it as a chemical reference material for laboratory research use only. In US pharmacy-compounding regulation, nicotinamide adenine dinucleotide (NAD) appears in the FDA document listing bulk drug substances nominated for use in compounding under section 503A (updated May 14, 2026) in Category 1, the list of substances under evaluation, while the beta-NAD disodium salt trihydrate is listed separately in Category 3, the nominations the agency regards as inadequately documented. NAD+ does not appear on the FDA page of bulk substances that may present significant safety risks. Those lists concern compounding pharmacies, not the sale of a research reagent; the framework for research compounds is set out in Peptide Legal Status 2026.

Frequently Asked Questions

Is NAD+ a peptide?

No. NAD+ is a dinucleotide with no amino-acid residues and no peptide bonds: adenine, nicotinamide, two ribose sugars and two phosphate groups, formula C21H27N7O14P2, 663.4 g/mol. Net peptide content and sequence do not apply to it.

Which molecular weight should I use for molar calculations?

The average molecular weight, 663.43 g/mol for the free acid, when converting a weighed mass to moles; the monoisotopic 663.109 Da only when reading a mass spectrum. For a stated sodium or lithium salt, use that salt's formula weight instead.

What is the difference between NAD+ and NADH?

NADH is the reduced form of the same dinucleotide: the nicotinamide ring gains a hydride, giving C21H29N7O14P2 (665.4 g/mol) and removing the pyridinium charge. NADH absorbs at 340 nm and NAD+ does not, and the two differ by 2 Da on a mass spectrum.

All products are supplied for laboratory research use only and are not for human or animal use.