Safety · 8 min read · Published September 8, 2026

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

What each field on a peptide COA means, what a purity percentage does and does not tell you, how to verify a Janoshik report, and the red flags the FDA's own 2026 review found in market products. No vendor recommendations.

What is a certificate of analysis?

A certificate of analysis is a lab report describing the results of specific tests on a specific sample: usually identity, purity, quantity and sometimes endotoxin or sterility. It is issued for one lot. It does not certify safety, does not cover storage after testing, and does not apply to any vial whose lot number differs from the one on the report.

This guide is about reading the document, not about where to buy anything. The Longevity Archive has no vendor relationships and does not name sources. The reason to understand a COA is that the arithmetic on every draw depends on it: if a vial labeled 10 mg contains 7 mg, every number the calculator gives you is 30 percent off.

The four fields that matter

What is a good purity level for peptides?

Pharmaceutical peptide drugs are typically specified above 98 or 99 percent by HPLC with named, limited impurities. For research-grade material, 98 percent or higher is the usual claim. But purity alone is not the point: a 99 percent pure vial with 6 mg where 10 mg is labeled, or with high endotoxin, is a worse product than a 97 percent pure vial that is accurately filled and clean.

How do you verify a Janoshik report?

Every genuine Janoshik report carries a task number and verification key. Enter both at verify.janoshik.com and compare the compound name, lot, HPLC purity, mass spectrometry identity and quantity to the document you were given. A purity percentage alone does not confirm the vial contains the labeled amount, the correct molecule, or is endotoxin free.

1. Find the task number and key on the report. They are printed on the document, not in the filename.
2. Open the verification page and enter both. If the report does not exist there, it is not a Janoshik report.
3. Check that the sample description, lot and date on the verified report match the document and match your vial.
4. Compare every measured field, not just purity. Altered PDFs usually change one number and leave the rest.
5. Note the sample submitter. Janoshik tests what it is sent; it does not select or vouch for the vial it came from.

Is Janoshik legitimate? It is an independent laboratory in the Czech Republic that publishes verifiable reports and is widely used because of that. Legitimacy of the lab is not the question; whether the sample tested is representative of what you received is, and no lab can answer that.

Red flags the FDA found

The FDA's briefing document for the July 2026 advisory committee review of BPC-157 (FDA media 193343) reported market products whose certificates of analysis did not match the named substance and inconsistent labeling of free base versus acetate salt. Those are two of the most common ways a COA misleads:

• Wrong molecule on the report. The COA names a related compound, a fragment, or a different salt from the label.
• Salt versus free base. A 10 mg acetate salt contains roughly 8.5 to 9 mg of peptide. Reports that do not state which they measured leave a 10 to 15 percent ambiguity.
• Purity without quantity. Discussed above.
• No lot number, or a lot that does not match the vial.
• A report older than the product's stated shelf life, or one issued before the lot's manufacturing date.
• 'Endotoxin: pass' with no number. A real LAL result is a value with units.

How do I know if my peptides are real?

You cannot know from the label. A lot-matched COA with verifiable identity, quantity and endotoxin results is the best available signal; independent testing of your own vial is the only proof. Commercial testing of a single sample costs roughly 60 to 200 US dollars depending on the panel, which is why community 'group tests' exist.

Testing at home is not possible with any accuracy; HPLC and mass spectrometry are laboratory instruments. Clarity, color and dissolving behavior tell you almost nothing about identity or purity, although visible particles or cloudiness after reconstitution are a reason not to use a vial (see the storage and reconstitution FAQ).

Why this matters more than the compound

Most of the compounds people test are unapproved and, as our profiles document, have thin or absent human evidence. The one variable a user can actually check is whether the vial contains what it says. That is a smaller question than 'does it work', and it is the only one a COA can answer.