How to Read a Certificate of Analysis (COA)

What a COA is

A Certificate of Analysis is a document issued for one specific production batch that records which tests were run on that batch, by whom, and what the results were. It is evidence about a batch, not about a product name: two vials of the same compound from different batches need two different COAs.

The fields that matter

• Product identity: the compound name, and ideally its synonyms, sequence or molecular formula.
• Batch or lot number: must match the number printed on the vial or packaging you received.
• Test date and laboratory: who performed the analysis and when. An independent laboratory named on the document is stronger evidence than an unnamed one.
• Method: for peptides, typically HPLC for purity and mass spectrometry (MS) for identity.
• Specification and result: the acceptance limit (for example "≥ 98.0%") next to the measured value (for example "99.1%"). A result without a specification tells you less.
• Supporting data: the HPLC chromatogram and the mass spectrum, not just a summary number.
• Sign-off: an authorized signature or electronic approval and a document or report number.

Purity is not the same as content

HPLC purity is the share of the detected signal that belongs to the target peptide. It does not measure how much of the powder by weight is peptide. Lyophilized peptides also contain counter-ions (such as acetate or trifluoroacetate) and residual water, so a vial can show high HPLC purity while its net peptide content is lower. Some COAs report peptide content or water content separately; when they do, read both.

Warning signs

• No batch number, or a batch number that does not match your vial.
• The same COA shown for every batch or every size of a product.
• A purity number with no method, no laboratory and no date.
• A test date after the product was already on sale, or years before it.
• Only a screenshot or product-photo overlay, with no downloadable report.

How Renuvia Labs publishes COAs

When a batch has a Certificate of Analysis, it is linked from the product page and listed in the COA library, searchable by product, SKU or batch number. Testing claims such as "HPLC-tested" appear on a product only when a matching batch record is on file.