How to read a certificate of analysis
A certificate of analysis, or COA, is a laboratory report on one batch of material. It is the only document in this market that carries testable information — which is exactly why it is worth knowing what it does and does not establish.
What each field means
- Product and batch number
- The certificate applies to one batch, not to the product in general. If the batch number on your vial is not the one on the certificate, the document describes different material.
- Date of analysis
- Tells you how old the result is. A certificate from two years ago says nothing about what is being shipped now.
- Testing laboratory
- The name and, ideally, contact details of whoever ran the test. A certificate with no identifiable laboratory cannot be checked by anyone.
- Purity, by HPLC
- Usually the headline number. HPLC separates the sample and measures how much of it is the intended compound. A figure without the method beside it is not meaningful.
- Identity, by mass spectrometry
- Confirms the substance is what the label says. Purity without identity tells you the vial is 99% of something, not 99% of the right thing.
- Appearance, solubility, water content
- Routine physical checks. Unremarkable when normal, and worth reading when not.
What makes a certificate worth less than it looks
- 01No batch number, or a batch number that does not match your vial.
- 02No laboratory named, or a laboratory that cannot be found to exist.
- 03An image rather than a document, especially a cropped one — the parts removed are often the identifying ones.
- 04A purity figure with no method stated beside it.
- 05A certificate the seller produced themselves rather than an independent laboratory.
What a COA cannot tell you
It describes a sample that a laboratory received. It cannot tell you that the sample came from the batch you were sent, that the batch was stored or shipped properly afterwards, or that the compound is safe to use. A clean certificate and an unstudied compound are entirely compatible — most of what is sold in this market has never been tested in a person, however pure it is.