Why the COA is everything
A Certificate of Analysis (COA) is third-party lab documentation confirming a compound's identity and purity for a specific batch. In a market with no central regulator of quality, it is the single best signal that a research material is actually what the label claims.
The key word is "batch." A COA matters only if it's tied to the specific batch you're buying. A generic, undated, or recycled COA tells you little.
What to look for
- Third-party lab — the testing should come from an independent lab, not the vendor's own bench.
- Batch / lot number — it should match the product you're buying.
- Purity figure — typically reported as a percentage (e.g. 99%+), usually via HPLC.
- Identity confirmation — mass-spec (MS) data confirming the molecule is what it claims to be.
- A recent date — old COAs don't represent current batches.
Red flags
- No COA available, or "available on request" that never arrives.
- A COA with no batch number or no lab name.
- Purity claims with no supporting document at all.
How we use COAs
Every vendor we review is scored partly on COA transparency. See how that factors into our rankings, and start with our top-rated vendor review.