LL-37 (5mg Vial) Dosage Protocol
Human cathelicidin host-defense peptide — unapproved research compound; no validated systemic dosing.
Pre-filled with this protocol’s recommended BAC water and documented starting dose — edit any field to run your own numbers. Reconstitution math only — not dosing advice. U-100 syringe: 100 units = 1 mL. Full reconstitution guide → · Advanced calculator →Mix & measure LL-37 · 5 mg
Dosing & Reconstitution Guide
A single practical dilution with accurate once-daily dosing, step by step
Standard / Gradual Approach (3 mL = ~1.67 mg/mL)
Reconstitute: Add 3.0 mL bacteriostatic water to one 5 mg vial → final concentration ~1.67 mg/mL (1,667 mcg/mL).
Illustrative daily range: 100–250 mcg once daily, raised gradually over a 12-week course. This range is educational syringe-math, not an established clinical dose.
Easy measuring: At ~1.67 mg/mL, 1 unit ≈ 16.7 mcg on a U-100 syringe, so doses fall on easy-to-read marks (6–15 units).
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.
Why LL-37 draws research interest
These are the directions researchers and the peptide community most often explore LL-37 for — so you know you’re in the right place. They describe what is being studied, not proven benefits, approved uses, or promised results.
Antimicrobial host defense
Studied as the human cathelicidin host-defense peptide for broad-spectrum antimicrobial activity in preclinical, cell-based research.
Wound healing & tissue repair
Investigated in animal and cell studies for roles in wound re-epithelialization and angiogenesis; unapproved, research-use only.
Immune modulation
Explored in research on innate-immune signaling and how the peptide shapes inflammatory responses; preclinical evidence only.
Skin inflammation
Researched as a modulator of skin inflammation, with preclinical work noting both protective and pro-inflammatory roles.
Evidence ranges from early laboratory work to clinical trials depending on the use — the sections below cover the actual data and sources.
Quickstart Highlights
LL-37 is the only human cathelicidin — a 37-amino-acid cationic host-defense peptide cleaved from hCAP-18 and produced by neutrophils and epithelial cells[1][5]. This educational page outlines an illustrative once-daily subcutaneous layout with a dilution chosen so doses land on easy-to-read insulin-syringe marks. LL-37 is an unapproved research compound, not a medicine; it is not approved by the FDA, EMA, or any regulator for any indication, and human experience is limited and early-phase (topical or intralesional/intratumoral). No validated systemic subcutaneous regimen exists — the schedule below is illustrative syringe-math, presented for research and educational use only.
Add 3.0 mL bacteriostatic water to one 5 mg vial → ~1.67 mg/mL (1,667 mcg/mL), the largest practical dilution for accurate dosing.
100–250 mcg once daily, titrated upward gradually across a 12-week course. Illustrative only — not an established clinical dose.
At ~1.67 mg/mL, 1 unit ≈ 16.7 mcg; 100 mcg ≈ 6 units and 250 mcg ≈ 15 units on a U-100 syringe.
Lyophilized: store at −20 °C (−4 °F); once reconstituted, refrigerate at 2–8 °C (35.6–46.4 °F) and do not freeze the solution.
Important: Start with the Prep & Injection Guide — it covers the preparation and safety basics every protocol on this site assumes.
Frequency: one subcutaneous injection each day, titrating up gradually. Published human experience with LL-37 has been topical or intralesional/intratumoral, not systemic subcutaneous[3][4]. This SC layout is illustrative syringe-math, not an approved or validated regimen.
Reconstitution Steps
Draw 3.0 mL of bacteriostatic water into a sterile syringe.
Release it slowly down the vial’s inner wall to limit foaming.
Swirl or roll gently until fully dissolved — don’t shake.
Label with the date and concentration, then refrigerate at 2–8 °C (35.6–46.4 °F), shielded from light.
The 3.0 mL dilution keeps each dose in an easy-to-read range (about 6-15 units), where U-100 syringe markings are clear. Avoid freezing the reconstituted solution, since freeze–thaw can denature the peptide.
Supplies Needed
Quantities below assume an 8–16 week course of once-daily injections with gradual titration.
At microgram-level daily doses, one 5 mg vial lasts several weeks. A generic research vial is shown; LL-37 is not sold here.
- 8 weeks: ~2 vials
- 12 weeks: ~4 vials
- 16 weeks: ~5 vials
- Per injection: 1 syringe
- 8 weeks (once daily): ~56 syringes
- 12 weeks (once daily): ~84 syringes
- 16 weeks (once daily): ~112 syringes
Use ~3.0 mL per 5 mg vial for reconstitution.
- 8 weeks (2 vials): ~6 mL → 1 bottle
- 12 weeks (4 vials): ~12 mL → 2 bottles
- 16 weeks (5 vials): ~15 mL → 2 bottles
One for the vial stopper + one for the injection site each day.
- Per injection: 2 swabs
- 8 weeks (once daily): ~112 swabs → 1–2 boxes
Protocol Overview
A concise summary of the illustrative once-daily layout. LL-37 has no validated systemic regimen; the figures below are educational only.
- ▪Goal: Illustrate microgram-level subcutaneous syringe-math for a human host-defense peptide with documented antimicrobial, immunomodulatory and wound-healing biology — effects reported in preclinical/early work, not established for systemic human use[5][6].
- ▪Schedule: Daily subcutaneous injections for 8–12 weeks, optionally extended to ~16 weeks for longer research goals.
- ▪Dose Range (illustrative): 100–250 mcg per day with gradual titration — educational syringe-math, not a clinical dose.
- ▪Reconstitution: 3.0 mL bacteriostatic water per 5 mg vial gives ~1.67 mg/mL for accurate unit measurements.
- ▪Storage: Keep the dry vial frozen at −20 °C (−4 °F); once mixed, refrigerate at 2–8 °C and do not freeze the solution.
Dosing Protocol
An illustrative daily titration layout for clear syringe measurement — educational only, not a clinical recommendation.
- ▪Start: Begin at 100 mcg once daily (6 units).
- ▪Titrate: Increase by roughly 50 mcg every two weeks as tolerated.
- ▪Target: Reach about 250 mcg daily (15 units) by weeks 7–12.
- ▪Cycle Length: Typically 8–12 weeks; some references extend to ~16 weeks.
- ▪Timing: Inject at a consistent time each day and rotate injection sites systematically.
Storage Instructions
Correct storage is what preserves the peptide’s stability and activity.
- ▪Lyophilized: Hold the dry vial at −20 °C (−4 °F) in dry, dark conditions and limit moisture exposure[7].
- ▪Reconstituted: Refrigerate at 2–8 °C (35.6–46.4 °F) and use within about 28 days; do not freeze the mixed solution, as freezing can denature peptides[8].
- ▪Handling: Let frozen vials warm to room temperature before opening so condensation won’t form, and keep the solution clear of heat and direct light.
- ▪Freeze–thaw: Avoid repeated freeze–thaw cycles of the reconstituted solution.
Important Notes
Practical points that keep daily administration safe and consistent.
- ▪Sterile technique: Use a fresh sterile U-100 insulin syringe each time and drop it straight into a puncture-proof sharps container afterward.
- ▪Site rotation: Move between abdomen, thighs and upper arms to reduce local irritation and lipohypertrophy[9].
- ▪Slow injection: Push the plunger slowly and pause a few seconds before withdrawing the needle to prevent backflow.
- ▪Recordkeeping: Log the daily dose, injection site and any observations to keep the protocol consistent.
- ▪Regulatory note: LL-37 is not approved by the FDA, EMA, or any regulator for any indication — an unapproved, research-only compound, not for human administration[10].
How This Works
LL-37 is the only human cathelicidin — a 37-amino-acid cationic, amphipathic host-defense peptide cleaved from the precursor protein hCAP-18 and produced mainly by neutrophils and epithelial cells[1][2]. Its amphipathic alpha-helix lets it insert into and disrupt microbial membranes.
Its core activities are broad-spectrum antimicrobial and anti-biofilm action via membrane disruption, plus immunomodulation — it binds and neutralizes bacterial LPS (endotoxin), modulates inflammatory signalling, and has been reported to promote wound healing and angiogenesis in preclinical models[5][6].
Human experience with LL-37 is limited and early-phase, and almost entirely topical or intralesional/intratumoral — for example, a Phase I study of intratumoral LL-37 in melanoma documented immune activation alongside dermatologic toxicity[11], and small topical studies have explored wound healing[12].
Important caveat: there is no established systemic subcutaneous regimen for LL-37, and no completed trials supporting systemic dosing. Documented safety concerns include cytotoxicity to mammalian cells, dermatologic toxicity seen in the intratumoral melanoma trial, inhibition of activity by serum, and low proteolytic stability. Any systemic “benefit” claims are hypotheses, not established findings.
LL-37 is not an approved medicine anywhere. It is an unapproved research compound presented here for research and educational purposes only, and does not treat, cure, or prevent any disease.
Lifestyle Factors
General wellness habits often discussed alongside research protocols; not specific to LL-37.
- ▪Nutrition: Keep protein intake adequate to give tissue repair the building blocks it needs.
- ▪Activity & rest: Pair appropriate movement with adequate rest and recovery time.
- ▪Sleep: Aim for 7–9 hours to support the body’s natural repair processes.
- ▪Stress: Manage stress with evidence-based practices, since it influences overall healing.
Potential Benefits & Side Effects
What preclinical and early-phase literature describe; human evidence is very limited and these are not established outcomes.
Potential Benefits
- ▪Antimicrobial & anti-biofilm (preclinical): Disrupts microbial membranes with broad activity and reduces biofilm formation in lab studies[5][6].
- ▪Immunomodulation (preclinical): Binds and neutralizes LPS (endotoxin) and modulates inflammatory signalling in laboratory models[11].
- ▪Wound healing / angiogenesis (preclinical): Reported to support re-epithelialization and new blood-vessel growth in preclinical and topical studies.
- ▪Note on humans: These effects are not established for systemic human use — clinical experience is limited to topical/intralesional/intratumoral settings[13].
Common Side Effects
- ▪Cytotoxicity & local toxicity: LL-37 can be cytotoxic to mammalian cells; dermatologic toxicity was documented in the intratumoral melanoma trial. Local injection-site reactions are also possible.
- ▪Unknown systemic profile: No validated systemic human safety data; serum inhibition and low proteolytic stability further limit predictability. Caution is warranted.
- ▪Not approved: LL-37 is not approved by any regulator for any indication and is for research use only.
Injection Technique
General subcutaneous technique, following established clinical best-practice guidance[14][15].
Pre-Injection Preparation
- ▪Wash your hands well with soap and water.
- ▪Wipe the vial stopper with an alcohol swab and let it air-dry.
- ▪Choose a site (abdomen, thigh, or upper arm) and clean it with a fresh alcohol swab, letting it dry fully[15].
- ▪Draw the intended dose, then check for air bubbles and push any out.
Injection Procedure
- ▪Pinch a skinfold at the chosen site between thumb and forefinger.
- ▪Insert the needle into the pinch at a 45–90-degree angle (use 45 degrees if the fat layer is thin)[14].
- ▪Skip aspiration for subcutaneous shots — it isn’t needed[14].
- ▪Press the plunger slowly and steadily until it’s fully down.
- ▪Wait 5–10 seconds, then pull the needle straight out to prevent leakage.
Post-Injection Care
- ▪Drop the used syringe straight into a puncture-proof sharps container — never recap a needle.
- ▪Return the reconstituted vial to the fridge right away.
- ▪Rotate the injection site each day to prevent irritation and lipohypertrophy[9].
- ▪Watch the site for excess redness, swelling, or signs of infection.
Recommended Source
LL-37 is not sold on this site. For general high-purity research-peptide sourcing, researchers can review Prime Lab Peptides. Always verify current product availability and certificates of analysis directly with any supplier.
Why Prime Lab Peptides?
- ▪Top-rated on Trustpilot: Independently reviewed as the highest-rated peptide lab on Trustpilot — making it the best current source in the USA.
- ▪Third-party tested: Every batch ships with a Certificate of Analysis (COA) confirming purity and composition.
- ▪Consistent quality: ISO-aligned manufacturing and handling keep product integrity reliable batch to batch.
- ▪Cold-chain integrity: Temperature-controlled shipping and storage across the whole fulfilment chain.
- ▪Research-grade purity: Fit for educational and research use that demands high-quality peptides.
Note: Product availability and specifications subject to change. Verify current product details on supplier website.
References
- 1
PubMedLL-37: the only human cathelicidin — structure, processing from hCAP-18, and host-defense functions.
- 2
PubMedAmphipathic structure and membrane-disrupting antimicrobial mechanism of the cathelicidin LL-37.
- 3
PubMedLL-37 immunomodulation: LPS neutralization and modulation of inflammatory responses.
- 4
ClinicalTrials.govLL-37 / cathelicidin clinical study registry — early-phase, topical and intralesional; no systemic approval.
- 5
- 6
- 7
Peptide Storage GuideBest practices for storing lyophilized peptides (temperature, humidity and light protection).
- 8
Bacteriostatic Water GuidanceBacteriostatic water for injection: multi-dose vial stability and handling.
- 9
NCBI BookshelfBest practices for subcutaneous injection: aseptic technique and site rotation.
- 10
U.S. Food & Drug AdministrationLL-37 is not an FDA-approved drug; unapproved research compounds are not for human use.
- 11
PubMedPhase I intratumoral LL-37 in melanoma: immune activation with documented dermatologic toxicity.
- 12
PubMedLL-37 limitations: mammalian-cell cytotoxicity, serum inhibition, and low proteolytic stability.
- 13
ClinicalTrials.govLL-37 trial registry — limited early-phase, topical/intralesional studies; no systemic dosing approval.
- 14
Centers for Disease Control and Prevention (CDC)Subcutaneous injection technique: angle, site and no-aspiration guidance.
- 15
Subcutaneous Injection Technique (Patient Education)How to administer a subcutaneous injection: clinical technique guidelines.
- 16
Prime Lab PeptidesResearch-peptide supplier (LL-37 not sold on this site) — purity specifications and certificates of analysis.
LL-37 — frequently asked questions
How do I reconstitute a 5 mg vial of LL-37?
Wipe the stopper with an alcohol swab, then inject your bacteriostatic water slowly down the inside wall of the vial. Let it sit and gently swirl until dissolved — never shake. Store the mixed vial in the refrigerator and draw doses with an insulin syringe. Use the calculator above to turn any dose into syringe units.
How much bacteriostatic water should I add to LL-37?
There is no single correct amount — more water simply spreads the same 5 mg of peptide across a larger volume, which makes small doses easier to measure accurately. 1 to 3 mL per vial is typical. Enter your chosen volume in the calculator above to see the resulting concentration and syringe units.
What do the "units" on an insulin syringe mean?
On a U-100 insulin syringe, 100 units equal 1 mL, so 1 unit equals 0.01 mL. The calculator above converts your draw volume into these units automatically so you can measure without doing the math by hand.
How should I store LL-37 after mixing?
Keep the reconstituted vial refrigerated at roughly 2 to 8 degrees Celsius, away from light, and avoid freezing it. Reconstituted research peptides are generally used within a few weeks. Always follow the specific guidance supplied with your product.
How many doses does a 5 mg vial of LL-37 provide?
Divide the vial strength of 5 mg by the amount you use per injection. The calculator above reports this as "doses per vial" the moment you enter a dose.
Is LL-37 approved for human use?
No. LL-37 is sold strictly for laboratory and research purposes and is not approved by the FDA or other regulators for human use. Everything on this page is research information, not medical advice — consult a licensed healthcare professional before any use.
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