How to Read a Peptide Certificate of Analysis
A practical laboratory checklist for reviewing a peptide CoA, matching a lot number, and separating identity, purity, and additional tests.
For research use only. Not for human or animal use. Not FDA approved. Pepmaxxing does not provide medical advice, dosage guidance, administration instructions, or treatment recommendations.
A useful peptide CoA should identify the material and lot, name the testing laboratory, show the test date, report the method and result, and distinguish purity from identity. Match the lot on the certificate to the material record, then check whether HPLC, mass spectrometry, and any additional tests cover the requirements of the intended laboratory workflow.
The six-point CoA check
Read the document as a chain of evidence rather than a marketing badge. Every field should help answer what was tested, on which material, by whom, when, and under which method.
- Compound name and material description
- Unique batch or lot identifier
- Testing laboratory and report identifier
- Analysis date and any retest or expiry information
- HPLC purity result and chromatogram where supplied
- Mass-spectrometry or other identity result where supplied
Match the document to the material
The lot identifier on the certificate should match the identifier supplied with the material. A generic example report, an undated image, or a certificate that cannot be connected to the purchased lot provides less evidence for that specific material.
Separate analytical questions
Purity asks how much of the detected chromatographic material corresponds to the reported peak. Identity asks whether the material matches the expected molecular characteristics. Endotoxin, sterility, residual solvents, heavy metals, and net content are separate questions and should not be inferred from an HPLC percentage.
Keep the record with the experiment
Store the certificate, lot identifier, product specification, and receipt record with the laboratory documentation. If the experiment has strict quality requirements, follow the institution’s own qualification and retesting procedures.