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Last reviewed: March 2026Sources: PubMed, FDA, WADA Prohibited List

Evidence graded using the PeptideScholar A-D system

LL-37

CPreclinical

Antimicrobial peptide (cathelicidin) · 37 amino acids

Not FDA ApprovedWADA Banned

LL-37 is the only cathelicidin antimicrobial peptide found in humans. It plays a crucial role in innate immune defense, wound healing, and inflammation modulation.

Mechanism of Action

Disrupts microbial membranes through electrostatic interaction with negatively charged phospholipids. Also modulates immune cell chemotaxis, inflammatory cytokine release, and promotes angiogenesis.

Benefits

  • Broad-spectrum antimicrobial activity (bacteria, fungi, viruses)
  • Immune modulation and anti-biofilm effects
  • Wound healing promotion
  • Potential anti-cancer properties in preclinical models
Not Medical Advice — Research-Reported Information Only

This content is for informational purposes only and does not constitute medical advice.

LL-37 — Dosing in Published Research

Reported Routes: Subcutaneous injection, Topical
Research dosing varies widely. Topical wound studies used 1-10 mcg/mL concentrations. No established systemic dosing.

The dosing information above is sourced from published research literature and clinical trials. These are not recommendations. Individual responses vary. Always consult a healthcare provider before considering any peptide-based therapy.

Side Effects

  • Limited human safety data for therapeutic use
  • Potential pro-inflammatory effects at high concentrations
  • Injection site reactions
  • Theoretical cytotoxicity at elevated doses

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LL-37 is not FDA-approved. Always consult a licensed healthcare provider before considering any peptide.

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Research & Evidence

ReviewInfection and Immunity, 2005

The human cathelicidin LL-37: a multifunctional peptide

Comprehensive review of LL-37 antimicrobial, immunomodulatory, and wound healing functions in human innate immunity

PMID: 15817886
ReviewExpert Opinion on Biological Therapy, 2014

Therapeutic potential of LL-37 and derived peptides

Review of LL-37 therapeutic applications including chronic wounds, infections, and cancer with discussion of delivery challenges

PMID: 24284364

Compare LL-37 With

LL-37 vs BPC-157
LL-37 vs TB-500

References

  1. 1. The human cathelicidin LL-37: a multifunctional peptide. Infection and Immunity, 2005. “Comprehensive review of LL-37 antimicrobial, immunomodulatory, and wound healing functions in human innate immunity” [PMID: 15817886]
  2. 2. Therapeutic potential of LL-37 and derived peptides. Expert Opinion on Biological Therapy, 2014. “Review of LL-37 therapeutic applications including chronic wounds, infections, and cancer with discussion of delivery challenges” [PMID: 24284364]

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Medical Disclaimer

This content is for informational and educational purposes only and does not constitute medical advice, diagnosis, or treatment recommendations.

Always consult a qualified healthcare provider before starting, stopping, or modifying any treatment. Do not disregard professional medical advice based on information found on this site.

No claims of therapeutic efficacy are made for substances that are not FDA-approved for the discussed indications. Research citations reflect published findings and do not imply endorsement.

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