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LL-37

Immune Modulation

LL-37 is a naturally occurring antimicrobial peptide in the cathelicidin family, integral to innate immune defense. It exerts antimicrobial, immunomodulatory, and wound-healing effects through membrane disruption, immune activation, and epithelial regeneration. Its applications span infectious disease, chronic wounds, and immune regulation.

Reconstitute
3 mL BAC + 5mg vial
17 mcg/unit
Daily Range
0.5–2 mg Topical
Applied once or twice daily depending on site and indication
Standard Dose
1 mg
Cycle
4–8 weeks
then reassess
LL-37cathelicidinantimicrobial peptideimmune modulationwound healing

Dosing & Reconstitution Guide

Research doses range from 1–5 μg/mL in vitro, or 1–10 mg/kg in animal models. LL-37 is not approved for use outside of the laboratory.

Standard / Gradual Approach

5mg Vialstandard
PhaseDoseVolume
Week 150 µg3 units (0.03 mL)
Week 2100 µg6 units (0.06 mL)
Week 3150 µg9 units (0.09 mL)
Week 4200 µg12 units (0.12 mL)
Week 5250 µg15 units (0.15 mL)
Week 6300 µg18 units (0.18 mL)
Week 7350 µg21 units (0.21 mL)
Week 8400 µg24 units (0.24 mL)

Protocol Summary

Topical: Applied once or twice daily depending on site and indication · Dose range 0.5–2 mg with gradual titration
Subcutaneous (SQ): Daily or every other day depending on inflammatory severity · Dose range 100–400 mcg with gradual titration
Cycle Length: 4–8 weeks typical; reassess before extending

Frequency & Cycling

SubQ Injection

200–400 mcg daily or every other day for 4–6 weeks. Repeat cycles as needed with immune monitoring.

Topical

Apply to affected area once or twice daily. Safe for use in infected wounds, burns, or epithelial inflammation.

🧪 Quick Start

Vial Size
5 mg
BAC Water
3 mL
Concentration
1.67 mcg/unit
Starting Dose
50 µg (3 units (0.03 mL))
Maintenance Dose
400 µg (24 units (0.24 mL))

Potential Benefits & Use Cases

LL-37 is not authorized for clinical use. This peptide is intended for laboratory research only.
Accelerates healing of chronic venous leg ulcers compared to placebo (human trial)
Improves granulation tissue formation in diabetic foot ulcers (human trial)
Demonstrates broad-spectrum antimicrobial action, reducing bacterial loads in sepsis models (preclinical)
Inhibits Pseudomonas and Staph biofilm formation at sub-MIC concentrations (preclinical)
Bridges innate and adaptive immunity through chemotaxis of neutrophils, monocytes, and T cells (preclinical)
Clinical data Strong preclinical Limited data

Mechanism of Action

→Disrupts microbial membranes via pore formation
→Neutralizes endotoxins such as lipopolysaccharides (LPS)
→Activates chemokine and cytokine signaling for immune cell recruitment
→Regulates toll-like receptor signaling pathways in epithelial and immune cells

Lifestyle & Optimization

timing

Consistent injection schedule during active infection or wound healing.

diet

Optimize vitamin D status (upregulates endogenous LL-37). Adequate protein, zinc, and vitamin C for wound healing.

exercise

Moderate activity as tolerated. Proper wound hygiene.

sleep

Adequate sleep and stress management.

Peptide Research & Preclinical Studies

Evidence-Based Research Findings

Study TitleType
DiVA Portal / Wound Repair and Regeneration — Evaluation of LL-37 in healing of hard-to-heal venous leg ulcers: multicentric RCTReference
Journal of Immunology (PMC) — Little peptide, big effects: the role of LL-37 in inflammation and autoimmune diseaseReference
Innate Immunity (PMC) — Antimicrobial peptide LL-37 ameliorates a murine sepsis model via microvesicle release from neutrophilsReference
Wound Repair and Regeneration (PMC) — Evaluation of LL-37 in healing of hard-to-heal venous leg ulcers: a multicentric prospective RCTReference
Archives of Dermatological Research (PMC) — Efficacy of LL-37 cream in enhancing healing of diabetic foot ulcer: a randomized double-blind controlled trialReference
Bachem Knowledge Center — Handling and storage guidelines for peptidesReference
PubMed / Journal of Steroid Biochemistry — Vitamin D and the antimicrobial peptide cathelicidin (LL-37)Reference

Side Effects & Safety

🧮 Dose Calculator

Concentration
16.7
mcg/unit
Draw Volume
30
units (0.300 mL)
For a 500 mcg dose, draw 30 units on a U-100 insulin syringe
🧬

Bioavailability & Absorption

SubQ Injection
High when injected; effects mostly localized to immune and epithelial tissues
Oral Administration
Poor bioavailability due to rapid enzymatic breakdown
Half-Life
Short systemic half-life; effects are mostly local and transient
Degradation
Metabolized by tissue proteases and immune-related enzymes
Tissue Specificity
Active in skin, lungs, oral cavity, GI tract, and mucosal surfaces
⚗️

Peptide Details

Molecular Weight
4493.3
Formula
C62H114N18O19
Sequence
LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES
⚖️

Legal Status & Regulatory

RegionStatus
FDANot Approved
EUNot Approved
AustraliaNot Approved
CanadaNot Approved

Storage Instructions

Lyophilized (Powder)
freeze at −20 °C (−4 °F); after reconstitution, refrigerate at 2–8 °C (35.6–46.4 °F) for up to 4 weeks; avoid freeze–thaw cycles
Reconstituted (Mixed)
Refrigerate at 2–8 °C (35.6–46.4 °F) for up to 4 weeks; frozen at −20 °C (−4 °F) for up to 6 months