LL-37 Protocol Guide
LL-37 is the only human cathelicidin antimicrobial peptide, a 37-amino-acid peptide that begins with two leucine residues. It is a key component of the innate immune system with broad-spectrum activity against bacteria, viruses, and fungi. LL-37 disrupts microbial cell membranes, breaks down bacterial biofilms, activates macrophages and neutrophils, and promotes wound healing through angiogenesis. It is researched for chronic infections, biofilm-associated conditions (Lyme, SIBO), wound healing, and immune modulation. This protocol covers reconstitution from a 5mg vial with 2mL bacteriostatic water, subcutaneous dosing at 100mcg daily, and antimicrobial stacking.
Protocol Overview
- Compound
- LL-37 (N-hexanoyl-Tyr-Ile-(6)-aminohexanoic amide)
- Category
- Antimicrobial / Innate Immune Peptide
- Mechanism
- Disrupts bacterial membranes, breaks biofilms, activates macrophages/neutrophils, promotes wound healing
- Structure
- 37 amino acids, human cathelicidin
- Half-Life
- ~4-6 hours
- Vial Size
- 5mg lyophilized powder
- Route
- Subcutaneous injection
- Frequency
- Once daily (morning)
- Cycle Length
- 4-6 weeks
Dosing Protocol
| Protocol | Dose | Frequency | Route | Duration |
|---|---|---|---|---|
| Standard Nootropic | 50 mcg | 1x daily (AM) | Subcutaneous | 4-8 weeks |
| Conservative Start | 25 mcg | 1x daily (AM) | Subcutaneous | 1-2 weeks, then assess |
| Research Maximum | 100 mcg | 1x daily (AM) | Subcutaneous | 4 weeks maximum |
Key principle: LL-37 is extremely potent at very low doses. Start with the lowest possible dose and increase only as needed. More is NOT better with this compound due to its exceptional potency at the HGF receptor.
Reconstitution Instructions
Materials Needed
- LL-37 10mg lyophilized vial
- Bacteriostatic water (2mL)
- 3mL mixing syringe (18-20ga)
- Insulin syringes (29-31ga) for dosing
- Alcohol swabs
Reconstitution Steps
- Clean vial stopper with alcohol
- Draw 2mL bacteriostatic water
- Inject slowly down the vial wall
- Gently swirl (never shake)
- Wait 5 minutes for full dissolution
- Concentration: 5,000 mcg/mL
| Dose | Volume (2mL recon) | Insulin Syringe |
|---|---|---|
| 25 mcg | 0.005 mL | 0.5 units |
| 50 mcg | 0.01 mL | 1 unit |
| 100 mcg | 0.02 mL | 2 units |
| 200 mcg | 0.04 mL | 4 units |
| 500 mcg | 0.10 mL | 10 units |
Administration Guide
Injection Sites
- Abdomen: Primary site, subcutaneous
- Thigh: Outer thigh, alternate sides
- Upper arm: Back of arm, alternate
Timing & Storage
- Timing: Morning administration for cognitive effects during the day
- Vial duration: ~200 days at 50mcg/day
- Storage (reconstituted): Refrigerate 2-8°C, use within 30 days
- Do not freeze reconstituted solution
Expected Timeline
Side Effects & Monitoring
Common Side Effects
- Injection site irritation (mild)
- Vivid dreams (commonly reported)
- Mild headache during initial days
- Increased mental stimulation/difficulty sleeping if dosed late
Limited safety data exists. LL-37 is a research compound with no human clinical trials completed. Exercise caution with dosing.
Precautions
- No human clinical trial data - preclinical only
- HGF/c-Met activation may theoretically promote tumor growth in predisposed individuals
- Avoid if history of cancer
- Extreme potency requires precise dosing - errors carry higher risk
- Not recommended during pregnancy or breastfeeding
Stacking Recommendations
Compatible Compounds
- Semax: Complementary nootropic via BDNF pathway
- Selank: Anxiolytic support during cognitive enhancement
- NAD+: Cellular energy for neuronal metabolism
- Cerebrolysin: Neurotrophic factor support
- GHK-Cu: Neuroprotective gene expression
Popular Stacks
- Cognitive Stack: LL-37 50mcg/day + Semax 600mcg/day
- Neuroprotective: LL-37 + NAD+ + Cerebrolysin
- Full Nootropic: LL-37 + Semax + Selank
Blood Work Recommendations
| Panel | Markers | Timing |
|---|---|---|
| Basic Panel | CBC, CMP | Baseline, Week 4 |
| Liver Function | ALT, AST, GGT | Baseline, Week 4 |
| Kidney | BUN, creatinine, eGFR | Baseline, Week 4 |
| Inflammatory | CRP, homocysteine | Baseline |
Monitoring is primarily precautionary given the limited human safety data. Track liver and kidney markers to ensure no organ stress from the compound.
Related Tools & Resources
