01 / RESEARCH SUMMARY
LL-37 Research Summary
LL-37 is the only human cathelicidin, a natural antimicrobial peptide made by immune and skin cells. It kills bacteria, fungi and some viruses, breaks up biofilms, and helps coordinate immune responses and wound healing. A small human trial in chronic venous leg ulcers showed faster healing. It can also promote inflammation and has been linked to psoriasis and rosacea.
Read the full guide →02 / WHY RESEARCHERS STUDY IT
Why LL-37 draws research interest
These are the areas researchers and the peptide community explore LL-37 for most often. They describe what is being studied — not proven benefits, approved uses, or promised results.
Infection defense
Kills bacteria and fungi and breaks up biofilms.
Wound healing
Sped healing of chronic leg ulcers in a small trial.
Immune signaling
Helps coordinate the body's immune response.
Evidence ranges from early lab work to large clinical trials depending on the use — see the sections below for the data and sources.
03 / DOSING & RECONSTITUTION
Dosing & Reconstitution Guide
A single practical dilution with accurate dosing, step by step
Standard Approach (2 mL = 2.5 mg/mL)
- Reconstitute: Add 2 mL bacteriostatic water to one 5 mg vial → final concentration 2.5 mg/mL (2,500 mcg/mL).
- Typical range: 100–500 mcg 1x daily · 3–5x a week.
- Easy measuring: At 2.5 mg/mL, 1 unit ≈ 25 mcg on a U-100 syringe, so doses read at 4–20 units — a 0.3 mL (30-unit) syringe makes them easier to read.
- Storage: Lyophilized: store at −20 °C (−4 °F); after reconstitution, refrigerate at 2–8 °C (35.6–46.4 °F) and do not freeze the mixed solution.
| Protocol | Dose range | Frequency | Half-life | Fasted | Route |
|---|---|---|---|---|---|
| Injectable · Subq | 100–500 mcg | 1x daily · 3–5x a week | Short (minutes–hours) | No | Subq |
04 / RECONSTITUTION CALCULATOR
Mix & measure LL-37 · 5 mg
Pre-filled with this protocol's recommended BAC water and starting dose — edit any field to run your own numbers.
- CONCENTRATION
- 2.50 mg/mL
- DRAW VOLUME
- 0.040 mL
- ON THE SYRINGE
- 4.0 units
- DOSES / VIAL
- 50
Reconstitution math only. U-100 syringe: 100 units = 1 mL.
Reconstitution GuideFull calculator →05 / STORAGE
Storage Instructions
Lyophilized (powder)
Store in the freezer at −20 °C (−4 °F) for long-term storage, or refrigerated at 2–8 °C for shorter periods. Keep dry, sealed and away from light. Let a frozen vial reach room temperature before opening to avoid condensation.
Reconstituted
Refrigerate at 2–8 °C (35.6–46.4 °F) and use within about 28 days. Do not freeze. Keep away from heat and direct light, and avoid repeated temperature swings. Swirl gently — never shake.
Reconstitution steps
- Wipe the vial stopper with an alcohol swab.
- Draw the BAC water and release it slowly down the inside wall of the vial.
- Swirl or roll gently until fully dissolved — don't shake.
- Label with the date and concentration and refrigerate.
06 / RESEARCH FINDINGS
What Research Shows
Preclinical / limited human evidence
- Antimicrobial activity, innate immune signaling, and wound biology are research areas.
Research context
LL-37 has complex inflammatory and disease-related effects. Antimicrobial activity in a dish is not evidence for safe systemic infection treatment.
07 / MOLECULAR BIOLOGY
Mechanism of Action
Investigational mechanism
Antimicrobial and innate immune pathways
A human cathelicidin peptide that can interact with microbial membranes and modulate immune signaling. Effects are context-dependent and may include pro-inflammatory actions.
Adamantane & the blood–brain barrier
Chemically attaching an adamantane group to a peptide can increase its lipid (fat) solubility. Researchers hypothesize that this modification may help certain compounds cross the tightly regulated blood–brain barrier. The effect depends on the specific modified molecule; greater lipid solubility alone does not establish brain delivery or clinical benefit. This does not apply automatically to the unmodified peptide and is not a reconstitution additive.
08 / LIFESTYLE FACTORS
Lifestyle Factors
- Load gradually: healing tissue still needs controlled, progressive loading — don't rush back to max effort.
- Sleep: most tissue repair happens during deep sleep.
- Nutrition: protein, vitamin C and collagen-supporting foods help connective tissue rebuild.
- Limit alcohol and smoking, which slow healing.
- Rotate injection sites; some inject near (not into) the injured area.
09 / BENEFITS & SIDE EFFECTS
Potential Benefits & Side Effects
Potential Benefits
- Faster recovery from soft tissue injuries (tendons, ligaments, muscle)
- Reduced inflammation and joint discomfort
- Gut lining support (BPC-157 and KPV)
- Improved skin quality and wound healing (GHK-Cu blends)
Side Effects
- Injection-site redness, itching or mild swelling
- Temporary fatigue or lightheadedness
- Headache or mild nausea
- Copper-peptide blends can sting at the injection site
10 / STUDIES
Studies & references
11 / SAFETY
Safety considerations
- Verify the active identity, lot number, and matching certificate of analysis. Testing does not by itself establish sterility or suitability for human use.
- Follow documented product-specific storage and preparation requirements; stability and diluent compatibility depend on the formulation.
- Research powders are not interchangeable with prescription formulations. Do not infer an injection or nasal protocol from a concentration calculation.
- For medical care, pregnancy, existing conditions, or medication interactions, consult a qualified healthcare professional.
12 / RECOMMENDED SOURCE
Recommended Source
For research peptides, we point researchers to Orbitrex Peptides for LL-37.
Why Orbitrex?
- Family-owned & independently tested: Multiple laboratories verify quality, with batch-specific testing in every COA.
- Everyday value: Buy 4, Get 1 Free on eligible products.
- Loyalty credit: 5% back in loyalty credit for future purchases.
- VerifyPass discount: 20% off for qualifying groups — stacks with affiliate codes.
- Free 2nd Day shipping: Free UPS 2nd Day Air on orders $200+, applied automatically at checkout.
All products are for research use only. Availability and offers subject to change.