What Should an NMN Certificate of Analysis Include? Purity, Potency and Identity Explained

Navigating the anti-ageing supplement market can feel like walking through a minefield. As Nicotinamide Mononucleotide (NMN) has surged in popularity, so too has the influx of substandard, underdosed, and sometimes entirely counterfeit products. For the research-led buyer and the sceptical shopper, marketing claims mean very little without verifiable proof, and that proof comes in the form of a Certificate of Analysis (COA).

However, not all COAs are created equal. Knowing how to read one, and knowing what data might be conveniently missing, is the only way to protect your health and your wallet. Here is exactly what a genuine COA should contain, and how to spot one that's cutting corners.

1. What is a Certificate of Analysis, and why does it matter for NMN?

A Certificate of Analysis (COA) is a formal, scientifically validated document issued by a quality assurance laboratory. It outlines the analytical tests performed on a specific batch of a product and details the results of those tests against accepted standards.

When it comes to NMN, a COA is non-negotiable.Because it is expensive to synthesise properly, the consumer is highly susceptible to adulterated products. Disreputable manufacturers may ‘cut’ their NMN with cheaper derivatives like standard nicotinamide (NAM), or use low-grade extraction methods that leave harmful chemical solvents and degradation byproducts in the powder.

If you want to understand how this molecule functions on a cellular level, our NMN & NAD+ guide covers the science in depth. But from a quality-control standpoint, understanding the molecule is only half the battle; you also need a guarantee that what you're actually ingesting is authentic, safe, and dosed correctly. Without a thorough COA, a brand's claims are simply marketing copy. A genuine COA replaces trust with hard, empirical data.

So what should that data actually cover? Here are five distinct tests

2. The five things a genuine NMN COA should test for

When you ask a brand for their NMN testing documentation, they will often hand over a sheet showing a single, high purity percentage. That's a red herring on its own: a purity figure alone tells you almost nothing about whether the finished capsule is safe or accurately dosed. To properly judge an NMN supplement, the COA needs to cover five distinct, non-negotiable parameters.

Identity Testing

Identity testing confirms that the white powder in your capsule is genuinely NMN, rather than standard Vitamin B3. This cannot be assumed from supplier paperwork. Identity must be verified through 3rd-party analytical methods such as High-Performance Liquid Chromatography (HPLC), Liquid Chromatography with tandem mass spectrometry (LC-MS/MS), or standalone mass spectrometry.[1] These methodologies analyse the specific molecular weight and chemical fingerprint of the substance, ensuring it perfectly matches the known profile of true NMN.

 Potency (Assay) Testing

It is not enough to know that a capsule contains some NMN; you need to know exactly how much. Potency (often labelled as "Assay" on a COA) confirms the percentage or milligram weight of labelled NMN actually present per capsule. If a label promises 500mg of NMN, potency testing verifies that 500mg made it into the final product. Poor manufacturing practices often lead to underdosed capsules, meaning you pay for a clinical dose but receive a fraction of the benefit.[2]

Purity Testing

Purity measures the exact percentage of the target molecule within the raw ingredient, confirming the compound is free from chemical byproducts and manufacturing residues. The industry standard for high-quality NMN is 99% purity or greater, signalling a highly refined and premium product.

Heavy-Metal Screening

Supplements derived from global supply chains are at risk of heavy metal contamination from soil, water, and poor processing equipment. A genuine NMN COA must show screening for the four primary toxic heavy metals: lead (Pb), arsenic (As), mercury (Hg), and cadmium (Cd). These elements can accumulate in the body over time, meaning daily supplementation of contaminated NMN could contribute to adverse health effects over time.

Microbial Testing

Microbial testing evaluates the biological safety of the product. This screens for yeast, mould, and dangerous bacteria such as Salmonella, E. coli, and Staphylococcus aureus. This is particularly relevant to capsule safety, as poor encapsulation environments or improperly stored raw materials can become breeding grounds for pathogens. To read more about how quality impacts well-being, see our NMN & NAD+: The Complete Guide.

The Ultimate COA Checklist

A checklist like this only means something if the document behind it actually reflects what's in your bottle, which raises the next question: whose testing are you really looking at?

3. Supplier COA vs independent third-party verification

One of the most common deceptions in the industry is the misuse of the raw-material supplier's COA.

When a brand buys raw NMN powder from a chemical manufacturer, the supplier provides a COA. This document shows the quality of the input raw material at the exact moment it left the factory. Many brands simply take this supplier COA, stick their logo on it, and publish it on their website as "proof" of quality.

This is fundamentally flawed. A raw-material supplier's COA only shows the purity of the input; it tells you nothing about what happens next. After the raw material leaves the supplier, it undergoes shipping, handling, mixing, encapsulation, and bottling at entirely different facilities. During this journey, the NMN can be mixed with fillers, accidentally contaminated with microbes in an unclean encapsulation plant, or intentionally underdosed to stretch the manufacturer's profit margins.

A credible brand will never rely solely on a supplier's paperwork. Instead, they will commission an independent, finished-product, batch-level COA, paying a certified, unbiased third-party laboratory (such as Eurofins or an ISO-accredited lab) to pull the final, finished capsules off the assembly line and test them. Independent, finished-product testing is the only way to verify that the supplement you hold in your hand is safe and accurately dosed. To understand more about our commitment to independent validation, see our UK brand-trust guide.

Independence is one thing; making sure that independent test actually applies to the exact bottle in your hand is another.

4. Batch numbers, traceability and how to check a brand's claims

Accountability relies on traceability. Every high-quality supplement should have a specific lot number or batch number stamped clearly on the base or the label of the bottle. This number is the vital link between your physical product and the laboratory data.

When you request a COA from a brand, you must ensure that the batch number on the certificate perfectly matches the batch number on your bottle. If a brand hands you a generic, undated COA, or a COA from a batch tested three years ago, it is completely meaningless for the product you are currently consuming.

A rigorous brand operates with full batch-level traceability. Every time a new manufacturing run is completed, a new sample must be sent for third-party analysis, and a new COA generated. As a customer, you have the right to request the specific COA for your exact batch.

If a brand refuses to provide a batch-specific COA, becomes evasive, or claims that their testing documents are "proprietary secrets", this is a glaring red flag. Reputable companies view their testing data as a badge of honour, not a closely guarded secret. You can see how seriously we take this level of transparency in our Y&E certifications deep dive.

Even a fully independent, batch-matched COA can still be used to create a misleading impression. That brings us to the number you'll see plastered across almost every NMN label: purity.

5. Why "99.9% pure" isn't the whole story

Walk into any health shop or browse any online marketplace, and you will see "99% Pure NMN" plastered across labels in bold, shiny text. It is a powerful marketing hook. But as a research-led buyer, you must recognise it for what it is: an incomplete picture.

As set out throughout this guide, purity is one piece of a five-part picture: identity, potency, purity, heavy metals and microbial safety together, not a single number on a bag.[3]

Consider this scenario: a factory creates NMN that is technically 99% pure. However, to save money on logistics, they encapsulate it in a facility with poor hygiene controls, leading to bacterial contamination. They also decide to cut costs by only putting 150mg of that pure NMN into a capsule labelled as 500mg, filling the remaining 350mg with rice flour.

In this scenario, the raw material was 99% pure, making the marketing claim legally defensible in a very narrow sense. Yet the final product is both biologically unsafe (due to microbial contamination) and entirely ineffective (due to being massively underdosed).

Purity without potency is a waste of money. Purity without heavy-metal and microbial testing is a risk to your health.[4] If you are serious about choosing a supplement that genuinely impacts your cellular health, demand the complete picture. For a detailed breakdown of the brands that actually meet these standards, see our Best NMN supplements guide.

Frequently Asked Questions

What is a Certificate of Analysis?

A Certificate of Analysis (COA) is an official testing document issued by an analytical laboratory. It serves as empirical proof that a specific batch of a product meets its defined specifications for identity, potency, purity, heavy metals, and microbial contaminants

Does every NMN brand test for heavy metals?

No. Independent testing is expensive, and many budget brands rely solely on their raw-material supplier's initial certificate rather than commissioning their own finished-product screening for lead, arsenic, mercury, or cadmium.

What is identity testing?

It's the step that proves the substance inside the capsule is chemically what it claims to be. Methods such as HPLC, LC-MS/MS or mass spectrometry compare the molecular fingerprint of the powder against the known profile of true NMN, ruling out cheaper stand-ins like plain Vitamin B3.

How is potency different from purity?

Purity is about the absence of contaminants: solvents, degradation byproducts, anything that shouldn't be there. Potency is about the presence of the right amount of the active ingredient: confirming the capsule genuinely contains the milligram dose printed on the label. A product can be pure and still be underdosed, or dosed correctly but impure; a genuine COA has to rule out both.

Can I ask a brand to see their COA?

Absolutely. Reputable, transparent supplement brands should readily provide independent, third-party, batch-specific COAs for their finished products on request. The most trusted brands go further and publish them directly on their websites.

Is 99% purity enough on its own?

No. A raw material can measure highly pure in a lab and still end up in an unsafe or underdosed finished product. Purity is only meaningful alongside identity verification, finished-product potency testing, heavy-metal screening and microbial testing: the full five-part picture, not one number in isolation.

References

[1] Bush JR, Baisley J, Harding SV, Alfa MJ. Consumption of Solnul™ Resistant Potato Starch Produces a Prebiotic Effect in a Randomized, Placebo-Controlled Clinical Trial. Nutrients. 2023;15(7):1582. DOI: https://doi.org/10.3390/nu15071582

[2] Grasset E, Briand F, Virgilio N, Schön C, Wilhelm M, Cudennec B, et al. A Specific Collagen Hydrolysate Improves Postprandial Glucose Tolerance in Normoglycemic and Prediabetic Mice and in a First Proof of Concept Study in Healthy, Normoglycemic and Prediabetic Humans. Food Sci Nutr. 2024;12(11):9607-9620. DOI: https://doi.org/10.1002/fsn3.4538

[3] Cesar TB, Ramos FMM, Ribeiro CB. Nutraceutical Eriocitrin (Eriomin) Reduces Hyperglycemia by Increasing Glucagon-Like Peptide 1 and Downregulates Systemic Inflammation: A Crossover-Randomized Clinical Trial. J Med Food. 2022;25(11):1050-1058. DOI: https://doi.org/10.1089/jmf.2021.0181

[4] Ribeiro CB, Ramos FM, Manthey JA, Cesar TB. Effectiveness of Eriomin® in managing hyperglycemia and reversal of prediabetes condition: A double-blind, randomized, controlled study. Phytother Res. 2019;33(7):1921-1933. DOI: https://doi.org/10.1002/ptr.6386