LL-37 (Cathelicidin) (5 mg Vial) Dosage Protocol
LL-37 is a 37-amino-acid antimicrobial peptide derived from the human cathelicidin protein. It exhibits broad-spectrum antimicrobial, immunomodulatory, and wound-healing properties.
⚡ Quickstart Highlights
Dosing & Reconstitution Guide
Route: Subcutaneous | Frequency: Once daily | Half-life: ~30 minutes
Standard Approach (3 mL = 1.67 mg/mL)
Reconstituting with 3 mL bacteriostatic water produces a concentration of 1.67 mg/mL. Volume per dose changes with concentration; mg dose itself does not change between vial sizes.
| Phase / Protocol | Dose | U-100 Units | Volume | Doses per vial |
|---|---|---|---|---|
| Week 1 (titration) | 50 mcg | 3 units | 0.030 mL | 100 doses |
| Week 2 | 100 mcg | 6 units | 0.060 mL | 50 doses |
| Week 3 | 150 mcg | 9 units | 0.090 mL | 33 doses |
| Week 4 | 200 mcg | 12 units | 0.12 mL | 25 doses |
| Weeks 5–8 (target) | 300 mcg | 18 units | 0.18 mL | 16 doses |
Reconstitution Steps
- Wipe the vial stopper and BAC water vial with alcohol; let dry.
- Draw 3 mL of bacteriostatic water into a sterile syringe.
- Inject slowly down the inside glass wall of the peptide vial. Do not aim at the powder.
- Gently swirl until fully dissolved. Do not shake.
- Label with reconstitution date. Refrigerate at 2–8°C; use within 30 days.
Supplies Needed
Estimates for an 8-week and 12-week cycle at 150 mcg per dose, once daily (7 doses/week).
| Item | 8-Week Cycle | 12-Week Cycle |
|---|---|---|
| LL-37 (Cathelicidin) (5 mg) vials | 2 vials | 3 vials |
| Insulin syringes (U-100) | 56 | 84 |
| Bacteriostatic water (10 mL) | 1 × 10 mL | 1 × 10 mL |
| Alcohol swabs | 1 × 100-pack | 2 × 100-pack |
Protocol Overview
LL-37 protocols are typically short cycles (2–4 weeks) for acute infection / wound research, longer (8–12 weeks) for chronic biofilm protocols.
Dosing Protocol
Daily dosing:
- Light (100 mcg/day): Conservative dose.
- Standard (250 mcg/day): Most-cited research dose.
- Higher (500 mcg/day): Acute infection / wound research.
Cycle: 2–4 weeks acute, 8–12 weeks chronic biofilm.
Storage Instructions
| State | Temperature | Duration |
|---|---|---|
| Lyophilized | −20°C (−4°F) | Up to 24 months, dry & dark |
| Reconstituted | 2–8°C (35–46°F) | Up to 30 days, protect from light |
Important Notes
How This Works
LL-37 is the active C-terminal fragment of human cathelicidin antimicrobial protein 18 (hCAP18), produced by neutrophils and epithelial cells as part of innate immunity. It disrupts bacterial membranes via amphipathic alpha-helical structure, binds bacterial LPS, and modulates immune cell trafficking and cytokine production.
Potential Benefits & Side Effects
Potential Benefits
- Broad-spectrum antimicrobial activity (gram+/–, fungi, viruses).
- Immunomodulation via dendritic cell activation.
- Promotes wound closure and re-epithelialization.
- Anti-biofilm activity in chronic wound models.
Side Effect Profile
- Generally well-tolerated.
- Mild injection-site reactions possible.
- Pro-inflammatory at high concentrations in some contexts.
Lifestyle Factors
- Adequate vitamin D supports endogenous LL-37 expression.
- Anti-inflammatory diet supports immune function.
Injection Technique
- Subcutaneous into abdomen, thigh, or upper arm. Rotate sites.
- Topical formulations exist for direct wound application in research.