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Immune System Support

LL-37 (Cathelicidin)

Potent antimicrobial peptide for biofilm disruption and wound healing

Overview

LL-37 is the only human cathelicidin-derived antimicrobial peptide, playing a central role in the innate immune system. It exhibits broad-spectrum activity against bacteria, viruses, and fungi, and is particularly noted for its ability to disrupt resistant bacterial biofilms. Beyond killing pathogens, it modulates inflammation and accelerates the re-epithelialization of chronic wounds. Supplied as a lyophilized peptide for research use.

Chemical Information

IUPAC Name
Human Cathelicidin Antimicrobial Peptide
Sequence
LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES
Molecular Mass
4493.3 g/mol
Formula
C205H340N60O53
LL-37 (Cathelicidin) Chemical Structure

Mechanism of Action

Functions as a cationic amphipathic α-helical peptide that acts as the body's 'first responder'. Its mechanism is dual-action: 1. Direct Membrane Disruption: Its positive charge attracts it to negatively charged bacterial membranes, where it inserts itself to form 'toroidal pores,' causing the pathogen to leak and die. This physical attack makes resistance nearly impossible. 2. Biofilm Destruction: It prevents the formation of (and degrades existing) bacterial biofilms, the protective 'slime' that renders antibiotics ineffective. 3. Immune Modulation: It acts as a chemotactic signal via the FPR2 receptor, recruiting neutrophils and monocytes to the infection site while simultaneously neutralizing toxic LPS (endotoxins) to prevent septic shock.

Potential Research Fields

Biofilm DisruptionWound HealingSepsisAntiviral DefenseCancer Immunotherapy

Recent Research

Recent research (2024–2025) is revolutionizing the view of LL-37 from a simple germ-killer to a 'biofilm buster' and immune calibrator. In chronic wound care (e.g., diabetic foot ulcers), studies confirm that LL-37 can penetrate the extracellular matrix of biofilms that block standard antibiotics, exposing the bacteria within. A major 2024 focus is its synergy with Vitamin D; since LL-37 expression is Vitamin D-dependent, researchers are finding that co-administration significantly boosts innate immunity against respiratory viruses. Furthermore, oncology studies are investigating LL-37's ability to turn 'cold' tumors (hidden from the immune system) into 'hot' targets by recruiting dendritic cells, offering a new frontier in cancer immunotherapy.

Bibliography / Scientific References

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Peptide Information Guide
Administration Type
Injectable (Subcutaneous)

Injectable administration protocol for research.

Vial Strength
5mg10mg
Reconstitution
Reconstitute with 2ml bacteriostatic water (for both sizes)
Dosage Options
0.5 mg (20 units)
Mon-Fri
Protocol for 5mg vial (Low Concentration)
0.5 mg (10 units)
Mon-Fri
Protocol for 10mg vial (High Concentration)
Schedule
5 days/week
Timing: One specific day.
Duration
According to the Doctor
Potential Side Effects
Injection site redness/sting
moderatevery common
Inflammatory flare (transient)
lowoccasional
Research Use Only

This information is for research purposes only. Always consult with a healthcare professional before starting any peptide protocol. Individual responses may vary, and proper medical supervision is recommended for all peptide therapies.