Most buyers look at a COA, see "99.4% purity," and stop there. A real Certificate of Analysis has several parts, and each one tells you something different.
The HPLC chromatogram
This is the headline test. Reverse-phase high-performance liquid chromatography separates the target peptide from related impurities. The purity figure is the area of the main peak as a share of all peptide peaks. Look at the chromatogram itself, not just the number: shoulder peaks or side peaks at 1 to 2% of the main peak are impurities.
Identity
The COA should confirm the compound is what the label says. Most certificates do this by matching the HPLC retention time to a reference standard. Some also confirm identity by mass spectrometry (LC-MS), which checks the molecular weight directly and is the stronger test.
Net content
Some certificates report net peptide content: the milligrams of peptide measured in the vial. It is usually a report-only figure, not a pass or fail line, and it lets you compare what was measured with what the label says. Purity and content are two different numbers.
What research-grade COAs usually do not include
Sterility, endotoxin, and heavy-metal panels are pharmaceutical-release tests, and most research-grade certificates, ours included, do not run them. Research-use material is not a sterile pharmaceutical product and should never be marketed as one.
Lab identification and verification
Who issued the COA? Is the lab named? Is the certificate tied to your specific lot? Does it carry an access code or QR code so you can check it with the lab directly? If any of these are missing, you are trusting the brand's marketing, not the data.
See real, unedited certificates for every lot we sell in our COA archive, and how we test each one on our method page.
No claims. No hype. Just the work behind the COA. Published before the box ships.