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COA Explained

Ten questions to ask any supplier

Send these before your first order. A supplier with a real testing process answers them quickly and specifically. Vague answers are an answer too.

  1. Is every lot tested, or only some?
  2. Is the testing done by an independent third-party lab, or in-house?
  3. Which lab, and is it accredited to ISO/IEC 17025 for the method used?
  4. Does each COA carry the lot number printed on the vial?
  5. Does the COA include both an identity test (mass spectrometry) and a purity test (HPLC with chromatogram)?
  6. How many vials from each lot are tested, and how are they picked?
  7. Can I confirm the report directly with the lab?
  8. How recent is the test for the lot I'd receive?
  9. What happens to a lot that fails testing? Is it destroyed, returned, or sold anyway?
  10. Will you send the COA for my exact lot before I pay?

Question 9 is the one that tells you the most. Any supplier can publish a passing report. The ones worth trusting can tell you about a lot they turned away.

How to judge the reports you get back: reading a COA line by line.

Where I point people: TrueVial, my sister's store, publishes a lot-specific COA for every lot it sells. Code JORDAN10 takes 10% off at truevial.co. It's an affiliate link: I earn a commission, and it costs you nothing extra.