How to Read a Peptide Certificate of Analysis: HPLC Purity, Mass Spec Identity, Endotoxin, and Janoshik Verification

What is a certificate of analysis?

This guide is about reading the report, not about where to buy anything. The Longevity Archive names sellers only on its price pages, sorted by how well their certificates hold up, and this guide names none. The reason to understand a certificate is that the math on every dose depends on it. If a vial labeled 10 mg holds 7 mg, every number the calculator gives you is 30 percent off.

The four lines that matter

What is a good purity level for peptides?

How do you verify a Janoshik report?

1. 01Find the task number and key on the report. They are printed on the report itself, not in the file name.
2. 02Open the checking page and enter both. If the report is not there, it is not a Janoshik report.
3. 03Check that the sample name, batch and date on the checked report match the copy you have, and match your vial.
4. 04Compare every measured line, not just purity. Edited PDFs usually change one number and leave the rest.
5. 05Note who sent the sample in. Janoshik tests what it is sent. It does not pick the vial or vouch for where it came from.

Is Janoshik legit? It is an independent lab in the Czech Republic. It publishes reports anyone can check, and that is why so many people use it. Whether the lab is real is not the question. The question is whether the sample it tested is the same as what you got, and no lab can answer that.

Red flags the FDA found

For its July 2026 advisory panel review of BPC-157, the FDA wrote a staff paper (FDA media 193343). It reported products on the market whose certificates did not match the named substance, and labels that mixed up the pure peptide weight and the salt weight. Those are two of the most common ways a certificate misleads:

• Wrong molecule on the report. The certificate names a related compound, a piece of the peptide or a different salt from the label.
• Salt weight or pure weight. A 10 mg acetate salt holds roughly 8.5 to 9 mg of actual peptide. Reports that don't say which one they measured leave a 10 to 15 percent gap.
• Purity but no amount. Covered above.
• No batch number, or a batch that does not match the vial.
• A report older than the product's stated shelf life, or one dated before the batch was made.
• 'Endotoxin: pass' with no number. A real LAL result is a number with units.

How do I know if my peptides are real?

You can't test at home with any accuracy. The machines that check identity and purity are lab machines. How clear it looks, its color and how it dissolves tell you almost nothing. But if you see bits floating in it, or it turns cloudy after mixing, don't use that vial (see the storage and mixing FAQ).

Why this matters more than the compound

Most compounds people test are unapproved. As our profiles show, most have few or no studies in people. The one thing a user can actually check is whether the vial holds what it says. That is a smaller question than 'does it work', and it is the only one a certificate can answer.