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How to Read a Certificate of Analysis (COA) for Research Peptides
The COA is the single most important document that comes with a research peptide. Here is how to check identity, purity and the testing lab, and how to spot a certificate you should not trust.
What is a Certificate of Analysis?
A COA is a report issued by an analytical laboratory after testing one specific batch of a substance. For research peptides it confirms two things:
A certificate for a different batch tells you nothing about the vial in front of you.
Product, batch and laboratory
Start at the top of the report. A proper COA clearly shows:
If the batch number is missing, the COA cannot be linked to a specific vial.
Identity: mass spectrometry (MS)
Mass spectrometry measures the mass of the molecules in the sample. Every peptide has a known theoretical molecular weight – BPC-157, for example, is about 1419.5 g/mol. The report compares two values:
The values should match closely, typically within about 1 Da. A large difference points to a different compound, a degraded product or a mislabelled vial.
Purity: HPLC
High-performance liquid chromatography separates the components of a sample and records each one as a peak on a chromatogram.
- The largest peak should be the target peptide.
- Purity is the area of that peak as a percentage of all peaks.
- For research-grade peptides, 98–99% or higher is a common standard.
A trustworthy COA shows the actual chromatogram, not just a number: one dominant, sharp peak with only small peaks around it.
Other tests you may see
Identity (MS) and purity (HPLC) are the essential minimum.
In-house vs independent testing
An in-house COA is produced by the manufacturer itself. An independent COA comes from a separate laboratory with no interest in the result, which makes it more objective. Some independent labs also provide a verification key or QR code, so you can confirm on their website that the report is genuine.
Why are some COAs redacted?
Many suppliers in the research peptide market work with contract manufacturers and keep those relationships confidential. That is why you will often see COAs where the manufacturer or client name is blacked out. This is common practice and does not by itself mean the report is unreliable.
Red flags
- No batch number, or it does not match the vial
- No test date or test method stated
- A purity number without a chromatogram
- Observed mass that does not match the expected mass
- A generic template reused across different products
- Results, masses or dates that are hidden or look altered
Quick checklist
- Product name matches the label
- Batch number matches your vial
- Test methods (HPLC and MS) are stated
- Observed mass matches the expected mass (MS)
- HPLC purity of 98–99%+ with a chromatogram shown
- Report is recent and clearly legible
- The seller can answer questions about the batch
COAs at Auron Elite. Our products are listed with the batch Certificate of Analysis provided by the manufacturer. Supplier names are redacted for confidentiality – the test results are shown unchanged. Products without a certificate are not offered for sale.
View our COAsAll products sold by Auron Elite are intended strictly for in-vitro laboratory research use only. Not for human or veterinary use, and not for consumption. This article is for informational purposes only.