Also known as Cathelicidin · hCAP-18 fragment
Human cathelicidin antimicrobial peptide active across bacteria, fungi, and viruses.
LL-37 is the C-terminal 37-residue fragment of human cathelicidin hCAP-18 and the only cathelicidin expressed in humans. Roles span direct antimicrobial activity, chemotaxis, and wound healing.
LL-37 is the only cathelicidin antimicrobial peptide expressed in humans — a 37-residue fragment released from the precursor protein hCAP-18. It is a frontline component of innate immunity, found in neutrophils, epithelial cells, and skin.
Beyond directly disrupting the membranes of bacteria, fungi, and some viruses, LL-37 also acts as a signaling molecule that recruits immune cells and supports wound healing. Interest has grown as antibiotic resistance renews attention on host-defense peptides. It is studied as a research compound.
Membrane disruption of pathogens; immunomodulatory signaling via FPRL1.
Behind every vial of LL-37 is the same exacting pipeline every research peptide runs — but the chemistry plays out differently for this molecule. Here is how LL-37, specifically, is brought into being.
On paper, LL-37 is C205H340N60O53 — about 4,493.3 daltons of precisely arranged atoms. Before a single bond is made, the target sequence, salt form, and purity threshold are written down as the contract the finished material must meet.
LL-37 is assembled by solid-phase peptide synthesis — the chain grows one protected residue at a time on resin, and what you fail to build cleanly here you pay to remove later.
The crude mixture — LL-37 plus its deletions and side products — is then separated on preparative HPLC, and where the cut is taken decides the difference between a genuinely pure peptide and a barely-passable one.
A real batch of LL-37 proves itself: identity confirmed by mass spectrometry against its ~4,493.3 Da, purity read directly off an analytical HPLC trace, water and counterion content measured. That batch-specific certificate of analysis is the only honest way to know what is actually in a vial of LL-37 — and a short, cold, accountable chain of custody is how that purity survives the trip to your bench.
Producing LL-37 to a genuine purity spec means solid-phase synthesis, preparative HPLC purification, and batch quality control — none of it cheap, and none of it something you can verify by eye.
Don't judge a vial by its cake. A fluffy, good-looking lyophilized powder reflects bulking agents and freeze-drying parameters — not purity. Insist on a batch-specific certificate of analysis.
Recent clinical trials and publications mentioning LL-37, pulled automatically from ClinicalTrials.gov and PubMed and refreshed daily. Listings are unfiltered search results, not curated endorsements.
LL-37 is the only human cathelicidin antimicrobial peptide, part of innate immunity, with direct antimicrobial and wound-healing roles.
As a host-defense peptide that disrupts microbial membranes, it represents a mechanism distinct from conventional antibiotics, of growing interest as resistance spreads.
Antimicrobial-resistance research, chronic wound healing, and innate immunity.
No — it is a research compound. This page is a research and educational reference.
Dosing protocols, mechanism, comparisons, and the latest trials — citation-backed answers grounded in PubMed, PubChem, and ClinicalTrials.gov.