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LL-37

Peptide

LL-37 (Leucine-Leucine-37) is the only human cathelicidin antimicrobial peptide, a 37-amino acid sequence cleaved from the C-terminus of the precursor protein hCAP-18. It is produced by neutrophils, epithelial cells, and other immune cells and plays crucial roles in innate immunity, wound healing, and antimicrobial defense. Clinical trials have demonstrated efficacy in treating hard-to-heal venous leg ulcers, while extensive preclinical research shows potent activity against antibiotic-resistant bacteria including MRSA biofilms.

Quick Answer

What it is

LL-37 (Leucine-Leucine-37) is the only human cathelicidin antimicrobial peptide, a 37-amino acid sequence cleaved from the C-terminus of the precursor protein hCAP-18. It is produced by neutrophils, epithelial cells, and other immune cells and plays crucial roles in innate immunity, wound healing, and antimicrobial defense.

Key findings

  • Grade B: Antimicrobial Activity (Immune Function)
  • Grade B: Biofilm Eradication (Immune Function)
  • Grade B: Re-epithelialization (Skin Health)

Safety

No specific caution or interaction language was detected in the current summary/outcome notes.

⚠️ Research Notice

This peptide information is for educational and research purposes only. Peptides may not be FDA-approved for human use and may only be legally available for research purposes. Consult qualified healthcare professionals before considering any peptide compounds.

ℹ️ Quick Facts: LL-37

Quick Facts: LL-37

  • Best Evidence:Grade B
  • Conditions Studied:3
  • Research Outcomes:21
  • Grade B Findings:4
  • Key Effect:Skin Health
A0
B4
C13
D4
3 conditions · 21 outcomes

Detailed Outcomes

|
B
Antimicrobial Activity
Effective against 38+ bacteria, 16 fungi, 16 viruses
large↑Improves
B
Biofilm Eradication
>4 log reduction in S. aureus biofilms
large↑Improves
C
Immune Cell Activation
Activates NK cells, dendritic cells, B cells
moderate↑Improves
C
MRSA Killing
Effective at nanomolar concentrations
large↑Improves
B
Re-epithelialization
Significant improvement in wound closure
large↑Improves
B
Venous Leg Ulcer Healing
6-fold higher healing rate at optimal dose
large↑Improves
C
Granulation Tissue Formation
Enhanced tissue regeneration
moderate↑Improves
C
Survival Rate
Improved survival in sepsis models
moderate↑Improves
D
Wound Healing
2 preclinical studies support this finding. Primarily preclinical evidence.
small↑Improves

Research Citations (73)

LL-37 Attenuates Sepsis-Induced Lung Injury by Alleviating Inflammatory Response and Epithelial Cell Oxidative Injury via ZBP1-Mediated Autophagy.
(2025)
PMID: 40559884
Human cathelicidin peptide LL-37 induces endothelial-to-mesenchymal transition.
(2025)
PMID: 40690262
Significance of the LL-37 Peptide Delivered from Human Cathelicidin in the Pathogenesis, Treatment, and Diagnosis of Sepsis.
(2025)
PMID: 40960088
Cathelicidin regulates goblet cell mucus secretion and mucus-associated proteins in Citrobacter rodentium-induced colitis.
(2025)
PMID: 40735968
Cathelicidin LL-37 in periodontitis: current research advances and future prospects - A review.
(2025)
PMID: 39954662
Cathelicidin Antimicrobial Peptide Levels in Atherosclerosis and Myocardial Infarction in Mice and Human.
(2024)
PMID: 38474156
Cathelicidin LL-37 promotes wound healing in diabetic mice by regulating TFEB-dependent autophagy.
(2024)
PMID: 38423213
Cathelicidin (LL-37) causes expression of inflammatory factors in coronary artery endothelial cells of Kawasaki disease by activating TLR4-NF-κB-NLRP3 signaling.
(2023)
PMID: 37773705
Cathelicidin LL-37 promotes EMT, migration and metastasis of hepatocellular carcinoma cells in vitro and mouse model.
(2023)
PMID: 36656313
Human cathelicidin LL-37 exerts amelioration effects against EHEC O157:H7 infection regarding inflammation, enteric dysbacteriosis, and impairment of gut barrier function.
(2023)
PMID: 36370932

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