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Guide2026-06-23·2 min read

The Two NMN Numbers That Actually Matter — Purity and Fillers Explained

An older man examining a supplement jar in his hands

Most NMN brands want you looking at their purity percentage. 99.8%. 99.9%. Big number, big trust, right?

Wrong.

The two numbers that actually tell you if a product is any good:

1. Potency (not purity)

Purity is the raw powder. Potency is what's in the finished capsule. I've sent product to labs where the purity certified at 99.5% — but the capsule tested at 62% of label claim. That means 38% was filler.

Always ask: "Is this potency tested on the finished product?" If they can't answer, walk away.

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2. Heavy metal panel (all four)

Lead. Arsenic. Mercury. Cadmium. If a brand shows you a COA with only potency — not metals — they're hiding something. NMN sourced from unverified manufacturers can carry heavy metal contamination. Testing costs money. Skipping it saves money.

That's it. Two numbers. Potency on the finished product. Full heavy metal panel. Everything else is marketing.

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