LL-37
Also known as: Cathelicidin, hCAP-18, Human Cathelicidin Antimicrobial Peptide
LL-37 is a 37-amino-acid peptide and the sole member of the human cathelicidin family of antimicrobial peptides. It is derived from the precursor protein hCAP-18 and is expressed by neutrophils, macrophages, epithelial cells, and other immune cells. LL-37 exhibits direct antimicrobial activity by disrupting microbial membranes and also serves as a key immunomodulator, promoting wound healing, angiogenesis, and chemotaxis of immune cells to sites of infection. Deficiency or dysregulation of LL-37 has been associated with increased susceptibility to infections, while overexpression is linked to autoimmune conditions such as psoriasis and rosacea. It is being investigated for its therapeutic potential in treating infections, biofilm disruption, and immune support.
Limited clinical data
Generally safe with some considerations
How It Works
LL-37 is a human cathelicidin antimicrobial peptide that disrupts microbial membranes, recruits immune cells, promotes wound healing, with broad-spectrum antimicrobial activity.
Key Benefits
- Broad-spectrum antimicrobial activity against bacteria, viruses, and fungi
- Disrupts biofilm formation
- Modulates innate immune response
- Promotes wound healing and angiogenesis
- Recruits immune cells to infection sites
- May enhance defense against upper respiratory infections
Who May Benefit
- Individuals with recurrent or chronic infections
- People seeking immune optimization
- Those with wound healing challenges
- Individuals supporting innate immune defense
Dosage & Administration
Expected Timeline
Immune benefits in 1-2 weeks. Chronic infection improvements over 2-4 weeks. Full protocols 4-8 weeks.
Safety Information
Possible Side Effects
Contraindications
Dr. Taylor's 2 Cents
“LL-37 is our body's own antimicrobial peptide, and supplementing it can meaningfully boost immune defense. I use it for patients with chronic infections, biofilm-related conditions, and those who seem to catch everything. It's also excellent for wound healing. The main caution is for patients with autoimmune skin conditions like psoriasis — LL-37 overexpression is actually part of the psoriasis pathology, so I avoid it in those cases.”
Discuss with Dr. Taylor →Frequently Asked Questions
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Published Research
Antimicrobial cathelicidin peptide LL-37 inhibits the pyroptosis of macrophages and improves the survival of polybacterial septic mice
Hu Z, Murakami T, Suzuki K, et al. · International Immunology (2016)
Key Finding: LL-37 improved survival in septic mice by inhibiting macrophage pyroptosis, modulating inflammatory cytokines, and reducing bacterial burdens in both peritoneal fluids and blood.
Therapeutic Potential of Cathelicidin Peptide LL-37, an Antimicrobial Agent, in a Murine Sepsis Model
Nagaoka I, Tamura H, Reich J · International Journal of Molecular Sciences (2020)
Key Finding: LL-37 demonstrated three protective mechanisms in sepsis: suppression of macrophage pyroptosis, enhanced neutrophil extracellular trap release, and stimulation of antimicrobial microvesicles.
Protocols Featuring LL-37
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Want personalized guidance?
Consult with Dr. Patrick Taylor for a comprehensive evaluation and personalized protocol.
Book a ConsultationMedical Disclaimer: This information is for educational purposes only and is not medical advice. Consult a healthcare provider before starting any peptide protocol.