By Inside Your Peptides · Originally published · Language revised 2026-09-17
A COA describes a tested sample using named methods. Check its issuer, accession, lot, identity, measured content, purity and contamination tests, then note what it cannot establish: every vial, sterility or clinical suitability.
Start with the document and the sample
Identify the issuing laboratory, accession number, sample description, lot and report date. Ask the laboratory whether it issued the report. A printed number, logo or vendor name is not proof of authenticity or proof that the sample represents every unit supplied.
Read each measurement separately
Identity asks what was detected. Measured content asks how much was measured. Chromatographic purity reports a result under a particular method; peak-area percentages are not automatically mass fractions. Endotoxin and microbial screening address different questions. Read units, method scope and detection or reporting limits.
Write down the gaps
Missing data are missing data, not a passing result. A microbial screen is not a sterility test. Even a sample-based sterility result does not guarantee every vial, establish clinical suitability or replace manufacturing controls. Use the report as evidence about the tested sample, not as a safety badge.
Sources used in this revision
- FDA · Pyrogen and endotoxins testing guidance · Checked 17 September 2026
- FDA · Sterile-manufacturing process controls · Checked 17 September 2026
Educational reading only. This page does not provide medical, dosing or personal-use guidance.