Provenance · 5 min · updated 2026-06-16
Reading a Certificate of Analysis
A Certificate of Analysis (COA) is a lab's statement about a specific batch. It is useful — and it is often misunderstood. This note covers what a COA proves, what it does not, and how to cross-check one yourself.
What a COA can tell you
- Identity — that the material is what it claims to be.
- Purity — the proportion of the stated substance, and notable impurities.
- The batch — a COA is tied to a batch number, not to a product line in general.
What a COA cannot tell you
- That a compound is safe for you, or lawful for a given use.
- That a different batch matches this one.
- Anything about dose — a COA is a chemistry document, not a clinical one.
Cross-checking a task ID
Every result we publish carries a testing-house task ID. To verify it:
- Note the batch number and the task ID on the product's COA block.
- Look the task ID up directly with the testing house.
- Confirm the batch, the date, and the purity figure match.
If a seller cannot give you a batch-linked COA you can independently verify, treat the claim as unproven.