A Janoshik COA is the strongest proof a research peptide is what the label says. Here is how to read one fast, and how to spot a fake.
Janoshik is an independent analytical lab widely used in the research peptide market to test identity and purity. A certificate of analysis, or COA, from Janoshik is simply their report on a specific sample. It is the difference between a supplier saying a product is pure and an outside lab measuring it. The report is the evidence behind the claim, which is exactly why it carries weight.
Open the report and check four things in order: the compound name matches what you are buying, the purity figure is present and high, the lab named is Janoshik or another recognised independent lab, and the date and sample reference are recent and specific. If all four hold up, the document is doing its job. If any are vague or missing, treat the purity as unconfirmed.
Purity is most often measured by high-performance liquid chromatography, or HPLC, which separates everything in the sample so each part can be measured. The main peak is your target peptide, and its size relative to everything else gives the purity percentage. Quality material is commonly reported above 98 to 99 percent. A real COA shows that number plainly, and often the chromatogram, the graph the instrument produces.
A high purity number is only half the story. You also want to know the molecule is the peptide claimed, not a cheaper lookalike. That is what mass spectrometry confirms: it effectively weighs the molecule and checks it against the expected mass. A strong COA reports both, purity by HPLC and identity by mass spec, so it answers "how much of it is real" and "is it the right thing" at the same time.
A PDF is easy to fake, so the best suppliers link to a report you can verify on the lab side rather than just hosting an image. Look for a verification reference or a link back to Janoshik. Cross-check the sample or batch reference on the report against the product you are buying. If a supplier only shows a screenshot and there is no way to confirm it came from the lab, treat it as a marketing image, not proof.
A COA is powerful but not magic. It reflects the sample that was tested, not necessarily every vial ever sold under that name, which is why recent, batch-specific testing matters more than one old certificate. It also says nothing about how the product was stored after testing, or about sterility. Use it as the strongest single signal of quality, not the only one. This is research-use information, not medical advice.
Research-use information only. Not medical advice.