LL-37
Also known as: Cathelicidin LL-37 · hCAP18/LL-37 · Human cathelicidin antimicrobial peptide
LL-37 is an amphipathic alpha-helical antimicrobial peptide that disrupts bacterial cell membranes through electrostatic interactions (cationic peptide binding anionic bacterial membranes) and membrane poration. It has broad-spectrum antimicrobial activity against gram-positive and gram-negative bacteria, fungi, and enveloped viruses. Beyond direct...
What It Is
LL-37 is an amphipathic alpha-helical antimicrobial peptide that disrupts bacterial cell membranes through electrostatic interactions (cationic peptide binding anionic bacterial membranes) and membrane poration. It has broad-spectrum antimicrobial activity against gram-positive and gram-negative bacteria, fungi, and enveloped viruses. Beyond direct antimicrobial activity, LL-37 modulates immune function: it activates macrophages, promotes wound healing via EGFR and VEGF signaling, stimulates angiogenesis, promotes re-epithelialization, and activates TLR4-independent innate immune signaling. It also inhibits biofilm formation and has anti-inflammatory effects on TLR-mediated signaling.
Supplies Needed
Reconstitution solvent
Injection - low-bind plastic prevents LL-37 adsorption to syringe
Sterilization
Storage
Store at -20C for up to 2 years. Relatively stable at 2-8C for several months.
Refrigerate at 2-8C; use within 30 days. Avoid adsorption to plastic surfaces (LL-37 is cationic and can bind to containers).
This information is provided for educational and research purposes only. Not approved for human consumption by the FDA or any regulatory body. Always consult a qualified medical professional.
Dosing Protocols
Timing: Any time; near infection or wound site preferred. Best used locally near infection or wound site; may not have significant systemic antimicrobial effect
↓ Apply these values to the reconstitution calculatorTiming: Any time; consistent schedule. For systemic immune support: subcutaneous; for wound healing: topical or subcutaneous near wound
↓ Apply these values to the reconstitution calculatorTiming: Any time. Higher doses for systemic immune modulation or chronic infection support; stack with Thymosin Alpha-1 for comprehensive immune function
↓ Apply these values to the reconstitution calculatorWeekly Timeline
| Week | Expected Effects |
|---|---|
| Week 1 | Antimicrobial protection at local injection sites; early wound healing acceleration; innate immune activation |
| Week 2 | Improved wound healing progress; reduced local infection signs; enhanced macrophage activity |
| Week 4 | Sustained immune support; wound healing complete for minor wounds; improved skin barrier integrity |
Reconstitution Calculator
1 unit on U-100 syringe = 0.01 mL · Always label your vial after reconstitution
Injection Technique & Reconstitution
- Remove flip-top cap from the vial
- Swab rubber stopper with alcohol swab
- Draw 2 mL bacteriostatic water into syringe
- Inject slowly down the vial wall
- Gently swirl until dissolved
- Label with date; refrigerate at 2-8C
Use our free LL-37 calculator to get the exact syringe units for your vial size and dose.
Mechanism of Action
LL-37 is an amphipathic alpha-helical antimicrobial peptide that disrupts bacterial cell membranes through electrostatic interactions (cationic peptide binding anionic bacterial membranes) and membrane poration. It has broad-spectrum antimicrobial activity against gram-positive and gram-negative bacteria, fungi, and enveloped viruses. Beyond direct antimicrobial activity, LL-37 modulates immune function: it activates macrophages, promotes wound healing via EGFR and VEGF signaling, stimulates angiogenesis, promotes re-epithelialization, and activates TLR4-independent innate immune signaling. It also inhibits biofilm formation and has anti-inflammatory effects on TLR-mediated signaling.
Key Research Papers
Comprehensive review of LL-37 functions including direct antimicrobial activity, wound healing via EGFR signaling, immune modulation, and anti-biofilm properties.
View on PubMed →Stacks Well With
Comprehensive immune support - LL-37 handles direct antimicrobial defense and innate immunity while Thymosin Alpha-1 modulates adaptive immune T-cell responses.
Wound healing stack - LL-37 provides antimicrobial protection and EGFR-mediated re-epithelialization while BPC-157 promotes deeper tissue repair via FAK/VEGF signaling.
Gut immune stack - LL-37 provides antimicrobial defense while KPV reduces NF-kB-driven gut inflammation. Complementary for gut dysbiosis and inflammatory gut conditions.
Frequently Asked Questions
LL-37 is a human antimicrobial peptide used for wound healing, broad-spectrum antimicrobial defense, immune modulation, and anti-biofilm activity. It is the only cathelicidin in humans and plays a key role in innate immune defense.
No - LL-37 has broad-spectrum antimicrobial activity but is rapidly degraded in vivo and lacks the pharmacokinetics needed to treat systemic infections like conventional antibiotics. It is best used locally for wound healing and immune support, not as a systemic antibiotic.
Legal Status by Region
This information is provided for educational and research purposes only. Not approved for human consumption by the FDA or any regulatory body. Always consult a qualified medical professional.