How to Read an NMN Certificate of Analysis (And Why Most Brands Don't Show You One)

I spent $300 sending five different NMN brands to an independent lab. Three of them came back with results that didn't match the label.

Here's what I learned — and what you should look for before buying any NMN supplement.

The Dirty Secret of NMN Purity Claims

When a brand says "99.8% pure NMN," they're almost always talking about the raw powder — before it's mixed with anything.

Here's the problem: between the raw powder and the capsule you swallow, manufacturers add flow agents (magnesium stearate, silica), fillers (rice flour, microcrystalline cellulose), and capsule material.

A typical 500mg capsule might contain:

300-350mg of actual NMN
100-150mg of flow agents and fillers
50mg of capsule shell

The label says 500mg. You're getting 60-70% of that. And the brand's purity certificate? It tested the powder before mixing. Not the finished capsule.

What a Real COA Looks Like

A legitimate Certificate of Analysis should include:

1. Finished product testing — not just raw ingredient testing. If the COA says "raw material" or "ingredient testing," it's not testing what's in the capsule.

2. Full panel — at minimum: potency (HPLC), heavy metals (lead, arsenic, mercury, cadmium), microbial (aerobic plate count, E. coli, salmonella). If a brand only shows potency, ask why.

3. Batch number and date — a real COA is tied to a specific production batch. If there's no batch number, it's generic. Might as well be a PDF they downloaded from the internet.

4. Third-party lab name — not the manufacturer's own lab. Independent labs like SGS, Eurofins, or Intertek. If the lab name is the same as the manufacturer, it's not independent.

The Three Numbers That Matter

When you do get a real COA, ignore the marketing numbers. Focus on these:

Number	What it means	Red flag
--------	--------------	----------
Potency (HPLC)	Actual NMN per capsule	Below 90% of label claim
Lead (Pb)	Heavy metal contamination	Above 0.5 ppm
Aerobic Plate Count	Bacterial contamination	Above 1,000 CFU/g

A product can claim 99.8% purity on the raw ingredient but still fail potency testing on the finished capsule. I've seen it.

Why Most Brands Don't Publish COAs

Publishing test results is scary for a brand. Every batch is different. One bad batch, one public result, and their entire marketing story collapses.

So they don't publish. They put "third-party tested" on the label without showing you the results. They show you a purity certificate from three years ago. They show you heavy metal results but conveniently leave out microbial.

The brands that publish every batch? They're betting their product is actually good.

What I Do Now

I test every batch at the finished product level. Full panel. Every result goes online. If a batch fails, it never ships.

It costs more. It takes more time. But I spent too many years buying NMN that wasn't what it claimed to be. I'm done with that.

If you're buying NMN from anyone — Mureen or otherwise — ask for the COA. Not the ingredient COA. The finished product COA. If they can't show it to you in thirty seconds, they're hiding something.