How to read a peptide COA, field by field

A COA is a table of claims. Reading one means knowing what each field asserts, what a passing value looks like, and which omissions are disqualifying. Here is the walk-through we use when reviewing submitted certificates.

The nine fields that matter

Field	What it asserts	What to look for
Product name	The substance and strength tested	Matches the label on the vial exactly, including concentration.
Lot number	The batch these results belong to	Present, specific, and identical to the lot printed on your vial. A COA without a lot number is decorative.
Testing lab	Who performed the analysis	A named laboratory with a real address and phone number — one you can contact. See independent labs.
Test date	When analysis happened	A real date, before the release date, not in the future, not years stale.
Identity	The substance is what the label says	A stated method (commonly HPLC retention match or mass spectrometry) with a pass result.
Potency / assay	How much active ingredient is present	A percentage of label claim with an acceptance range (for example 90–110%). Be suspicious of exactly 100% or values over 100% with no range stated.
Sterility	No microbial growth (injectables)	Method referencing USP <71>, result "no growth" / pass.
Endotoxin	Bacterial endotoxin below limit	Method referencing USP <85>, a numeric result with units (EU/mL or EU/mg) against a stated limit — not just the word "pass".
Beyond-use date	How long the lot is considered usable	Present and consistent with the test date.

Reading results, not just checkmarks

A trustworthy COA states the method, the specification, and the measured value. "Sterility: pass" with no method reference is weaker than "Sterility (USP <71>): no growth observed at 14 days." Numbers with units and stated acceptance ranges are the signature of a real lab report; bare checkmarks are the signature of a template.

Then verify it

Reading tells you whether the document is coherent. It cannot tell you whether it is authentic — a fabricated COA can be internally perfect. Continue to how to verify a COA and scan the red-flag list.