How to read a COA
A certificate of analysis is the laboratory’s report for one lot. Here is what each part tells you, and how to pull up the report for the vial in your hand.
- 01Testing laboratory
The independent lab that ran the analysis. A certificate should come from a third party, not the seller.
- 02Product and lot number
The compound, the labelled amount and the lot (batch) number. Match this lot number to the one printed on your vial.
- 03Dates
When the sample was received and when the report was issued. Recent dates mean the report reflects current stock.
- 04Identity (LC-MS)
Mass spectrometry compares the measured molecular weight with the expected one. A match confirms the vial holds the right compound.
- 05Purity (HPLC)
The main peak’s share of the total signal on the chromatogram. Higher is cleaner; small extra peaks are impurities.
- 06Content per vial
How many milligrams the lab measured in the vial, compared with the amount on the label.
- 07Endotoxin, heavy metals, sterility
Where reported: endotoxin by the LAL test (USP <85>), heavy metals by ICP-MS (USP <232>) and sterility by culture (USP <71>).
- 08Verification
A signature and a unique report code let you confirm the report directly with the lab.
Scan the vial
Every label links to its own lot’s report.Find the code
Each vial label has a QR code marked “Scan for CoA” and the lot number printed beside it.
Scan with your camera
Point your phone’s camera at the code and tap the link. No app is needed.
Match the lot
The certificate for that lot opens. Check that its lot number matches the one on your label.
What a trustworthy COA looks like
Lot numbers that match
The lot on the report should match the lot on your vial. A report with no lot number tells you little.
A real, named lab
The lab should be named and independent. Use the report code to confirm the report with them.
Identity and content, not only purity
Purity alone doesn’t prove what’s in the vial. Look for mass-spec identity and a measured amount per vial too.