Written by the AllMyPeptides Research Team
What Is a Certificate of Analysis (COA)?
A Certificate of Analysis (COA) is a formal document issued by an independent laboratory that verifies the identity, purity, and quality of a specific batch of a research peptide. It is the single most important document you should receive with any peptide purchase, and it serves as objective proof that the product has been tested and meets stated specifications.
At AllMyPeptides, every batch of every peptide comes with its own COA. We do not batch-test once and reuse the same certificate. Each batch is independently analysed, and the results are specific to that batch number.
Why Is a COA Important?
Without a COA, you have no way of knowing whether the peptide you received is what the label claims it to be. The COA provides independent verification from a third-party laboratory that the product has been tested for identity and purity. This is essential for research reproducibility — if your peptide is impure or misidentified, your research results may be invalid.
What Does a COA Typically Include?
A comprehensive COA will include: the product name and batch number, the date of manufacture and testing, the testing laboratory name, HPLC purity percentage (typically showing a chromatogram), mass spectrometry data confirming molecular weight, appearance description, and storage conditions. Some advanced COAs also include amino acid analysis and endotoxin testing results.
Understanding HPLC Testing
High-Performance Liquid Chromatography (HPLC) is the gold standard method for determining peptide purity. In HPLC analysis, the peptide sample is passed through a chromatographic column, and different components separate based on their chemical properties. A UV detector measures the output, producing a chromatogram — a graph with peaks representing different compounds.
The main peak represents your target peptide. The area of this peak relative to the total area of all peaks gives the purity percentage. At AllMyPeptides, we require 99%+ purity on our HPLC analysis before a batch is approved for sale. Any batch falling below this threshold is rejected.
The chromatogram on your COA shows this visually. A single, sharp main peak with minimal secondary peaks indicates a high-purity product. Broad peaks or significant secondary peaks suggest impurities or degradation.
Understanding Mass Spectrometry
Mass spectrometry (MS) confirms the molecular weight of the peptide. In MS analysis, the peptide is ionised and passed through a mass analyser, which measures the mass-to-charge ratio of the ions. The resulting mass spectrum shows the molecular weight of the peptide.
This test confirms identity — that the molecule in the vial matches the expected molecular weight of the peptide you ordered. If the measured mass does not match the theoretical mass, the product may be incorrect, degraded, or contaminated.
Frequently Asked Questions
Do I get a COA with every order?+
What does 99%+ HPLC purity mean?+
Can I trust a COA from the supplier themselves?+
What is mass spectrometry and why does it matter?+
How do I read the HPLC chromatogram on my COA?+
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Products discussed in this guide are for research and laboratory use only. AllMyPeptides does not condone or support misuse of any research materials. Not for human or animal consumption.