A Certificate of Analysis (COA) is the single most important document attached to any research compound — yet it’s also one of the most misunderstood. A COA is only as trustworthy as the laboratory that issued it and the methods behind it. This article explains what a COA actually proves, and why a supplier’s own COA should never be the end of the story.
What a COA actually contains
A meaningful COA confirms two distinct things about a batch of material: its identity (is the compound what the label says it is?) and its purity (what proportion of the sample is the target compound versus impurities?). A complete COA will typically state the compound name and sequence, the batch or lot number, the analytical methods used, the purity result as a percentage, the date of analysis, and the name of the issuing laboratory.
If any of those fields are missing — particularly the lab name, the method, or the batch number — the document tells you very little.
Supplier-issued vs independent COAs
Most research compounds change hands several times before reaching the end buyer. At each step, a COA may be passed along — often the one originally produced by the manufacturer. The problem is obvious: a manufacturer testing its own product has a clear conflict of interest, and there is no guarantee the certificate even matches the batch you receive.
An independent COA removes that conflict. The material is sent to a separate, third-party laboratory that has no stake in the result. The lab issues the certificate directly, tied to the specific batch tested. That is the difference between “we’re told it’s 99% pure” and “an independent lab measured this batch at 99% pure.”
What to look for
- The certificate names the issuing laboratory — not just “tested in-house”
- The batch or lot number on the COA matches the vial you received
- Both identity (e.g. mass spectrometry) and purity (e.g. HPLC) are reported
- The date of analysis is recent and present
Our approach
At VeridianLabs, independent third-party testing is commissioned by batch. Each product page states whether results are confirmed or pending. Where confirmed, the applicable laboratory documentation is published or made available against that batch; supplier-issued certificates are not described as independent verification.
All VeridianLabs products are sold strictly for laboratory research use only (RUO) and are not intended for human or veterinary use. This article is provided for general research and educational information only and does not constitute medical, dosing, or regulatory advice.
