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LL-37

Also known as: Cathelicidin, hCAP-18 Active Peptide

Compounding Eligible

Molecular Formula

C205 H340 N60 O53

Molecular Weight

4,493.33 Da

Half-Life

~1 hour (cellular); 43.5–74.6 hours (stabilized plasma conditions)

Sequence

LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES

Clinical Applications & Evidence

Mechanism of Action

Eradicates pathogens via a non-pore-forming 'carpet mechanism' that disrupts bacterial lipid bilayers through electrostatic interactions. Modulates immunity by neutralizing lipopolysaccharides (LPS), acting as a chemoattractant via FPRL-1, activating EGFR and MAP kinase pathways for angiogenesis, and complexing with nucleic acids to stimulate Toll-like receptors.

Investigated Uses

  • Chronic and recurrent infections
  • Biofilm-associated infections
  • Upper respiratory infection prevention
  • Wound healing support
  • Lyme disease adjunct (investigational)
Moderate Clinical Data

Regulatory & Safety Status

FDA Status

Compounding Eligible

WADA / Athletic Status

Prohibited in Competition

Known Side Effects

Cytotoxicity to normal eukaryotic cells at elevated concentrations (≥ 13–25 μM)Localized pro-inflammatory flaresMucosal overgrowth

Contraindications

  • Autoimmune conditions (may exacerbate)
  • Rosacea (paradoxical LL-37 overexpression)

Drug Interactions

  • May interact with immunosuppressant therapies
  • Synergistic with certain antibiotics

Citations & Clinical Trials

PubMed Wound healing activity of the human antimicrobial peptide LL37 ClinicalTrials.gov Efficacy of LL-37 Cream on Bacteria Colonization, Inflammation Response and Healing Rate of Diabetic Foot Ulcers FDA Pharmacy Compounding Advisory Committee; Notice of Meeting (April 2026)