LL-37
Cathelicidin LL-37 — Human Antimicrobial Peptide
What is LL-37?
LL-37 is the only cathelicidin in the human body — a naturally occurring antimicrobial peptide (AMP) that forms part of the innate immune system's first line of defense. It is produced by neutrophils, epithelial cells, and keratinocytes in response to infection and injury. Beyond antimicrobial activity, LL-37 promotes wound healing, modulates inflammation, and has been studied in cancer biology.
LL-37 exerts antimicrobial activity by disrupting bacterial, viral, and fungal cell membranes through electrostatic interaction with negatively charged microbial surfaces. It also acts as a chemoattractant for immune cells, stimulates angiogenesis, promotes wound closure, and modulates TLR signaling to balance inflammatory response without excessive tissue damage. Its immunomodulatory properties go well beyond simple antimicrobial action.
Research Evidence
Multiple studies demonstrate LL-37 accelerates wound closure through angiogenesis promotion, cell migration stimulation, and modulation of inflammatory resolution.
Broad-spectrum antimicrobial activity against bacteria, viruses, and fungi well-established in vitro. Particularly studied for biofilm disruption.
Community use for skin conditions, chronic wounds, and immune support. Limited controlled injectable human trial data.
Evidence grades: Gold = RCT human data · Silver = consistent animal/human data · Bronze = limited or preliminary
Dosing Protocols
Reconstitution Guide
| Vial Size | BAC Water | Concentration | Target draw |
|---|---|---|---|
| 5 mg | 5 ml | 1 mg/ml | 1mg = 100 units |
| 10 mg | 10 ml | 1 mg/ml | 2mg = 200 units |
Frequently Asked Questions
What is LL-37 used for?
LL-37 is used for wound healing acceleration, chronic skin conditions (psoriasis, rosacea, acne), antimicrobial applications, and general immune support. It is one of the most researched antimicrobial peptides in humans and has a well-characterized mechanism of action.
Can LL-37 be used topically?
Yes — topical application is well-studied and is the most common route for skin conditions and wound healing. Injectable SubQ is used for deeper tissue applications and systemic immune modulation.
References
- [1]Zanetti M. Cathelicidins, multifunctional peptides of the innate immunity. J Leukoc Biol. 2004;75(1):39-48.
- [2]Vandamme D, Landuyt B, Luyten W, Schoofs L. A comprehensive summary of LL-37, the factotum human cathelicidin peptide. Cell Immunol. 2012;280(1):22-35.
This profile was prepared using AI-assisted research synthesis. Citations are provided where applicable — verify with primary sources before clinical application.
Share this article