LL-37 lab tests

Seven checks before you trust a LL-37 certificate

The same seven questions decide whether a certificate of analysis means anything, whichever compound it describes. Six are about the document; the seventh is about what no document can tell you.

1. An independent, batch-matched COA. The certificate must name the batch or lot in your hands, and must come from a laboratory the vendor neither owns nor pays. A specimen certificate from an earlier lot proves nothing about the vial you were sent.
2. HPLC purity, read against a known band. A purity figure is only informative against the distribution for that compound. "Above 98%" is not a claim — the useful question is whether the result sits inside the range the rest of the market reports. How to read HPLC and mass-spec results.
3. Mass-spectrometry identity. HPLC says how much of the sample is one thing; it does not say which thing. Only a mass-spec result establishes identity, and it is the only check that separates compounds a few daltons apart.
4. Net content, measured rather than assumed. Purity and quantity are different questions: a vial can be 99.7% pure and still contain two thirds of the labelled mass. Why 10 mg isn't 10 mg.
5. Endotoxin (LAL) on the batch. An absent endotoxin line means the batch was not tested — not that it passed. Endotoxin testing and LAL interpretation.
6. Who ran the test, and what they left off. A laboratory with a record on this compound, named on the certificate, with a verification route back to it. Testing laboratories we track · Red flags in a certificate of analysis.
7. What no test on the vial can establish. A perfect certificate confirms that a vendor sold the correct molecule at the stated quantity. It says nothing about efficacy, dosing, or long-term safety.

Want a vial tested yourself? How to send a peptide for independent HPLC testing.