LearnHow to read a COA
Research overview
How to read a COA
What a lot certificate actually covers — identity, purity, net content — and what we publish here.
Heads up: this is product info for lab and research use only. It isn't medical advice, and it doesn't diagnose, treat, cure, or prevent any disease.
One lot, one document
A certificate of analysis describes a single lot — one production batch — not every future vial that shares the catalog name. If the paper and the vial disagree on the lot number, they are not the same report. Match the lot on the label to the lot on the PDF before you treat the numbers as belonging to that bottle.
The document does not travel forever. A later lot of the same listing is a different batch. A catalog card that says the shop uses a third-party lab is not a substitute for the lot paper.
Identity, purity, and net content
Those three lines answer different questions. Identity (often a mass spec result) asks whether the material matches the named sequence — is this the peptide on the label? Purity (often HPLC) asks how much of the measured sample is that peptide versus other peaks in the same run. Net peptide content asks how much of the weighed powder is peptide at all, after water, salts, and leftover process material are counted.
That last point is why the milligrams printed on a vial are not always the milligrams of peptide in the powder. The label is a fill weight for that listing. The COA’s net content, when the lab reports it, is a measured fraction of that fill. The two numbers can differ without either one being a typing error. Do not collapse them into one “strength” figure.
Fields worth checking
Start with the lot number, then the test date and the lab name. Those three tell you which batch was measured, when, and by whom. If a chromatogram is attached, it is the trace behind the purity line — peaks and a time axis, not a marketing graphic. A retest or expiry date, when present, is the lab’s window for that report, not a promise about every later vial.
If a field is blank, it is blank. Inventing a purity percentage or a lot code to fill the gap does not make the document stronger.
What we publish here
Roll-Peptide listings are Third-party tested. Lot PDFs go on product pages when we have the file for that lot. We do not invent COA files, lot numbers, or download buttons so a page looks finished. If a listing has no PDF yet, inquire with the product and size — do not assume a missing file means a missing test.
Many of our lots are tested by Janoshik, and each of those reports has a public verify page. How to read and verify a Janoshik COA walks through one line by line.
For vial vs booster formats and what we will not print on a listing, see how research peptides are supplied. Bench concentration math — mass and volume only — sits on the reconstitution calculator. Mixing, dosing, and protocols stay off this site.
Where this shows up in the catalog
Size, form, and the third-party tested badge sit on each product page. Lot PDFs go there only when we have that lot — not as invented downloads. Examples: BPC-157, Tesamorelin, Reta GLP-3, NAD+, and KLOW. Matching notes: What is BPC-157?, What is tesamorelin?, What is retatrutide?, NAD+ research overview, and What is KLOW?.
Related listings
Nearby catalog cards for what this page covers.
This is product information, not medical advice, and not a prescription. Nothing here diagnoses, treats, cures, or prevents disease. Talk with a licensed clinician before using any peptide or booster.