A certificate of analysis (COA) is the laboratory’s record of what was tested in one specific batch and what it found. It is only useful if you can tie it to the vial in front of you and know what each number means. This guide goes through a typical certificate section by section, using the reports in our COA Bank as examples.
1. The header: who tested it, and when
At the top you should find:
- The laboratory’s name and contact details. An independent lab should be identifiable and reachable.
- A unique report number. Our Bioviridian reports use the format COA10355. Freedom Diagnostics uses a ten-digit number.
- Dates. Usually a received date and a reported date. The test date should come after the batch was made and before the batch was sold.
2. The sample: what exactly was tested
This section names the compound, the label claim (for example “10 mg”) and, most importantly, the lot or batch number. The lot number is the link between the paper and the vial. If a certificate has no lot number, it can’t be matched to any particular batch, so it tells you very little.
Always check it against the lot number printed on your vial.
3. Identity: is it the right molecule?
Identity is usually confirmed by mass spectrometry (MS). The report compares the mass the instrument observed with the theoretical molecular weight of the compound. A close match confirms the expected molecule is present. Some certificates simply say “Identity: confirmed via MS”. Better ones also show the observed mass. (HPLC vs mass spectrometry explains how this works.)
4. Purity: how much of the sample is the target compound?
Purity is usually measured by HPLC and reported as a percentage, such as 99.8%. That figure is the share of the UV signal that comes from the main peak. It measures how much of the sample is the target compound compared with related impurities. It does not measure the total weight of peptide in the vial.
5. Content: how much is actually in the vial?
Some certificates also report the measured quantity. For example, one of our ISLA-RT 10 mg batches measured 10.64 mg. This is the figure to work from when you need to know how much material you have, rather than relying on the label alone.
6. Safety-related tests
- Endotoxin. Reported in EU/ml (endotoxin units). A result such as “<0.05 EU/ml” means it was below the method’s detection limit. See Endotoxin testing explained.
- Heavy metals. Usually reported in ppm.
- Sterility. Reported as detected or not detected.
7. Verification
Many labs print a verification code or QR code so you can look the report up on the lab’s own website. This is the best defence against an edited PDF.
Red flags
- No lot number, or a lot number that doesn’t match the label.
- Purity above 100%, or identical figures across unrelated compounds.
- A lab that can’t be found or contacted, or a report that can’t be verified.
- A test date after the product went on sale, or years before it.
- Only one certificate shown for a product sold across many batches.
Browse every Isla certificate in the COA Bank. All products are for in-vitro laboratory research only.
Research use only
Isla Longevity supplies research compounds for laboratory use only. They are not approved by the FDA for human or veterinary use and are not for human consumption. This article explains analytical testing and is not medical guidance.
