Research Compound
LL-37: what it is & how it’s tested
LL-37 is a 37-amino-acid peptide derived from the human cathelicidin protein (hCAP18). It is supplied lyophilised as a research compound for in vitro laboratory study only.
For in vitro laboratory research only. Not for human or animal consumption; not intended to diagnose, treat, cure or prevent any condition. 18+.
LL-37 is a 37-amino-acid peptide derived from the human cathelicidin protein (hCAP18). It is supplied lyophilised as a research compound for in vitro laboratory study only.
What LL-37 is
LL-37 is the active peptide released from the C-terminal end of the human cathelicidin protein hCAP18. It is named for its length (37 amino acids) and its first two residues (both leucine). It is manufactured and studied as a defined research compound.
Its sequence is confirmed by mass spectrometry and its purity measured by HPLC, so each batch can be reported on an independent Certificate of Analysis.
Where LL-37 appears in research
In the research literature, LL-37 is studied in antimicrobial-peptide and immunology research models. This describes the research domain in which the compound appears, not a claim of any effect. LL-37 is not a medicine, supplement or cosmetic, and is not approved for human or veterinary use.
How LL-37 should be tested
Quality is a matter of evidence, not the label. A credible supplier tests every batch at an independent laboratory: HPLC measures purity as a percentage (commonly to a ≥99% benchmark), and mass spectrometry confirms the compound’s identity.
The result should be a batch-specific Certificate of Analysis you can verify at source. Learn how to read a COA, or see BioHack London’s independent LL-37 reports.
Storage, handling and reconstitution
Lyophilised (freeze-dried) LL-37 is generally kept cool, dry and out of light. Reconstitution — dissolving it in a suitable solvent such as bacteriostatic water — is done immediately before laboratory use, and the reconstituted solution is typically refrigerated and used within a limited period.
Our reconstitution calculator helps work out solvent volumes, and bacteriostatic water is available in the range.
LL-37: frequently asked questions
What is LL-37?
LL-37 is a 37-amino-acid peptide derived from the human cathelicidin protein (hCAP18). It is supplied as a lyophilised research compound for in vitro laboratory research use only.
Why is it called LL-37?
The name reflects its structure: it is 37 amino acids long and begins with two leucine (L) residues. It is the active peptide released from the human cathelicidin precursor protein.
How is LL-37 tested?
A credible supplier tests each batch at an independent laboratory — HPLC for purity (commonly to a ≥99% benchmark) and mass spectrometry to confirm identity — and publishes a batch-specific Certificate of Analysis you can verify at source.
Is LL-37 for human use?
No. LL-37 is supplied strictly for in vitro laboratory research. It is not for human or animal consumption and is not intended to diagnose, treat, cure or prevent any condition. Purchasers must be 18 or over.
Related research compounds
LL-37, independently tested and verifiable.
Every batch is tested to a minimum 99% purity, with a Certificate of Analysis you can verify.