How to Read a Peptide COA

A Certificate of Analysis (COA) is a laboratory document describing tests performed on a particular lot. It should be evaluated as lot-specific documentation, not as a general promise about every product a supplier has ever sold.

1. Match the lot number

Start with the lot or batch number on the product record, vial, or shipping documentation. The COA should identify the same lot. A report for a different lot does not verify the material currently being supplied.

2. Check identity testing

Identity testing helps determine whether the tested material is consistent with the named compound. Common methods may include mass spectrometry or another documented analytical method. Check that the method, result, and laboratory are named clearly.

3. Understand HPLC purity

HPLC purity is an analytical result reported under a specific method and calculation. It is not the same as sterility, endotoxin testing, net content, or suitability for human use. Review the reported percentage, chromatogram, test conditions, and laboratory information.

4. Review net content and physical information

Look for the stated amount, format, appearance, dates, storage conditions, and any relevant moisture or residual-solvent information. The amount printed on a label and the amount measured by a test are not automatically identical.

5. Separate purity, identity, sterility and endotoxin claims

One test does not establish every quality characteristic. If sterility, endotoxin, heavy-metal, or other testing is important to a project, the specific result and method should appear in the documentation or be clearly identified as outside the report’s scope.

6. Check the issuing laboratory

Record the laboratory name, report date, report number, methods, and contact or verification pathway when available. A downloadable report is more useful when another researcher can verify its origin and lot match.

What a COA does not prove

• It does not approve a product for human or veterinary use.
• It does not establish that a product is legal to sell for every destination or purpose.
• It does not replace institutional procurement, safety, or regulatory review.
• It does not prove that an older report applies to a newer lot.

Related research information

Read the Retatrutide research guide or review the current research-use-only policy.