I bought supplements for other people for a decade. Then I tested them myself, and I couldn't unsee what came back.
Before NMN, there was everything else.
I wasn't a brand owner back then. I was a buyer — sourcing raw ingredients from Chinese manufacturers for European clients. My obsession was antioxidants. I touched nearly every major category.
I learned how supply chains worked, where they bent, and where they broke. The pattern was always the same: a beautiful COA, a confident supplier, a happy client — and occasionally, a lab result that didn't match.
Spermidine
AutophagyWheat germ extract. The molecule that taught me supply chains can break anywhere.
Ergothioneine
Longevity vitaminMushroom-derived. The first product I ever sent to an independent lab.
Silymarin
Liver healthMilk thistle extract. Europe’s best-selling botanical — and one of the most counterfeited.
Betaine
Methyl donorAlso called TMG. Cheap to make, easy to cut. I’ve seen it all.
Fisetin
SenolyticThe newcomer. Strawberry-derived. Early data is fascinating — early adulteration, too.
Categories I sourced for years before NMN.
Amsterdam. Winter.
The shipment failed. The client stayed.
Late afternoon. The canals were grey and motionless. By 4 PM the sun was already gone. I was sitting in my client's office — a Dutch man in his sixties who had been in the supplement business longer than I'd been alive.
Between us, on the table: his coffee cup, empty. Mine, untouched. 500 kilograms of spermidine, two weeks late. Spoiled in transit. Improper storage. A shipment worth more than I care to remember.
I was the youngest person in that room. The only Chinese. The one with the most to prove. I was not just representing my company — I was carrying the weight of every stereotype about Chinese suppliers. Every mistake confirmed their assumptions. Every silence felt like an admission.
“So,” he said. Just that one word.
I had nothing. My English was fine for emails. But sitting across from a man I respected, with nothing good to say — the words wouldn't come. I could feel the heat crawling up my face. In Chinese we call it diu lian — losing face. I was losing it in a foreign country, in front of the one client I'd spent two years earning.
In this business, you get one chance. Sometimes none. Sitting in that chair, I knew: this was probably my last meeting with this man.
Then something happened that I didn't expect.
Our supplier — a Chinese factory we'd worked with for three years, who had never failed us — did not make excuses. They pulled stock from other clients' orders, re-routed within 48 hours, and got enough material moving to keep my client's production line alive.
I spent the next two weeks giving him daily updates. Not because I had good news. Because I wanted him to know I was still there. Still accountable. Not hiding.
After the shipment arrived, he asked me to stay for dinner.
“I've worked with many suppliers,” he told me, years later. “Most disappear when something goes wrong. You didn't.”
That man gave me a second chance. I was lucky — I know that. Most people don't get second chances. I got one because of two things: a supplier with real accountability, and a client willing to see the person behind the mistake. We're still friends today.
After Amsterdam, I stopped trusting. I started testing.
I sent samples of everything — spermidine, ergothioneine, silymarin, betaine, fisetin — to independent labs. HPLC for purity. ICP-MS for heavy metals. Microbial panels for safety.
What came back was not one bad batch. It was a pattern — across categories, across suppliers, across countries.
When I finally turned to NMN, I wasn't surprised. I was exhausted. The same game, different molecule.
That's when I stopped being a middleman. I built Mureen — not just for NMN, but for every category I'd watched fail.
Label claim vs. independent lab
Figures from my own purchasing and lab files. Individual results vary by brand and batch — this is what I saw, not a survey.

I bought a ‘99% pure’ antioxidant. The lab said 52%.
Not NMN. This was ergothioneine — a European brand, beautiful packaging, €89 a bottle. HPLC showed the active compound was cut 48% with maltodextrin. The COA they sent? Tested the raw powder before blending. The finished capsule was a different story entirely.

A supplier charged me 3x for ‘fermented.’ It was chemically identical to synthetic.
This happened with spermidine. Premium story, premium price. I believed it for a year. Then I ran NMR spectroscopy. Same molecule. No biological difference. I had been passing a markup to my customers for nothing.

I asked 11 brands for their finished-product COA. Most couldn’t produce one.
Not raw powder. Not a three-year-old certificate. A full-panel test on the capsule you’d actually receive. Silymarin, betaine, fisetin — same story across the board. Beautiful websites, confident claims, no finished-product testing. That was the moment I knew: if I wanted supplements I could trust, I’d have to build them myself.
