What it is
LL-37 is a potent antimicrobial peptide of the cathelicidin family that combats bacteria, viruses, and fungi while modulating the immune response. Beyond its direct antimicrobial activity, it regulates inflammation, supports wound healing, protects gut barrier integrity, and contributes to skin defence and repair.
Mechanism of action
Amphipathic α-helical peptide that disrupts microbial membranes via electrostatic interaction. Also signals through FPR2 and EGFR on host cells, promoting keratinocyte migration, angiogenesis, and resolution of inflammation.
Half-life: Short in plasma — minutes; tissue activity persists longer.
Evidence summary
Strong in-vitro and animal data across bacterial biofilms (S. aureus), viral infections (influenza), and fungal pathogens (Candida auris). Wound-healing and gut barrier work demonstrate immunomodulatory benefit beyond direct antimicrobial action.
Typical dosing protocols
- 100–1,000 mcg subcutaneous, daily
- 4-week cycles for chronic infection or biofilm-related research
- Topical preparations explored for wound and skin applications
Side effects & safety
- Injection-site reactions
- Possible mild flu-like symptoms during initiation
- Long-term human safety data is limited
Cited studies
- (2019). Antimicrobial peptide LL-37 is bactericidal against Staphylococcus aureus biofilms. PLOS ONE.Read source ↗
- (2011). Antiviral activity and increased host defense against influenza infection elicited by the human cathelicidin LL-37. PLOS ONE.Read source ↗
- (2022). Antifungal Activity of Human Cathelicidin LL-37, a Membrane Disrupting Peptide, by Triggering Oxidative Stress and Cell Cycle Arrest in Candida auris. Journal of Fungi.Read source ↗
- (2005). Induction of keratinocyte migration via transactivation of the epidermal growth factor receptor by the antimicrobial peptide LL-37. Journal of Immunology.Read source ↗
- (2023). Human cathelicidin LL-37 exerts amelioration effects against EHEC O157:H7 infection regarding inflammation, enteric dysbacteriosis, and impairment of gut barrier function. Peptides.Read source ↗
All content is for research and educational purposes. Peptides described are sold for laboratory research use only and are not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional before beginning any protocol.
