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Peptide Library / Recovery / Immune

LL-37

Cathelicidin antimicrobial peptide

LL-37 Research Protocol

Complete Research Guide 4 min read1 peer-reviewed references

Quickstart Overview

LL-37 is the only human cathelicidin antimicrobial peptide — a 37-residue host-defence peptide central to innate immunity. It is studied for direct antimicrobial activity, wound healing, biofilm disruption and immunomodulation.

Reconstitution
Add 2.0 mL bacteriostatic water to a 5 mg vial → 2.5 mg/mL
Literature Range
100–500 mcg per administration
Measuring Reference
At 2.5 mg/mL: 250 mcg = 0.1 mL = 10 units
Frequency
Daily / EOD
Route (studies)
Subcutaneous
Cycle
2–4 weeks

Scientific Data

Molecular Formula
—
Molecular Weight
4493.3 Da
Sequence
LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES
Sequence Length
37
CAS
Research compound
Peptide Family
Antimicrobial peptide
Half-life
Refer to published literature
Solubility
Bacteriostatic water, sterile saline
Storage
Lyophilized: -20°C. Reconstituted: 2–8°C, use within 2–4 weeks.
Appearance
White lyophilized powder
Standard: 5 mg vial · 2 mL diluent

Dosing & Reconstitution Guide

Interactive Reconstitution
Adjust vial size, diluent and target dose. Results update live.
Full Precision Calculator →
Concentration
2.50 mg/mL
Draw Volume
0.100 mL
Syringe Units
10.0 U
Doses / Vial
20

Units assume a U-100 insulin syringe (100 units = 1 mL). A host-defence peptide; can be pro-inflammatory at high concentrations.

Frequency: Daily or EOD

Reconstitution Steps

  1. 1Allow the lyophilized vial and bacteriostatic water to reach room temperature (~15 min).
  2. 2Swab both vial stoppers with a fresh 70% isopropyl alcohol pad and let them dry.
  3. 3Draw 2.0 mL of bacteriostatic water into a mixing syringe.
  4. 4Insert at an angle and let the water run slowly down the glass wall — never directly onto the powder.
  5. 5Gently swirl (do not shake) until the solution is completely clear.
  6. 6Label with date and concentration (mg/mL) and refrigerate at 2–8 °C immediately.

Supplies Needed

Planning example for a 4-week protocol at approximately 250 mcg per day.

Peptide (5 mg vials)
Estimate vials from total mass: 250 mcg/day × 28 days.
Bacteriostatic Water
One 10–30 mL vial typically covers a full cycle.
Insulin Syringes (U-100)
One per administration (29–31 G, 0.3–0.5 mL).
Alcohol Swabs
Two per administration (vial + site).
Sharps Container
Required for safe disposal.

Protocol Overview

Goal
Model innate antimicrobial defence and wound healing.
Schedule
Daily/EOD, 2–4 weeks.
Dose Range
100–500 mcg per dose.

Dosing Protocol

Standard
100–500 mcg per administration
Frequency
Daily or every other day
Target
250 mcg typical
Cycle Length
2–4 weeks
Timing
Not time-critical
Route
Subcutaneous

Storage Instructions

Lyophilized
−20 °C long term (18–24 months); stable at room temperature for short transit.
Reconstituted
2–8 °C refrigerated; use within 4 weeks.
Light
Protect from direct light; keep in the original carton.
Freeze/Thaw
Avoid repeat freeze–thaw cycles after reconstitution.

Important Notes

  • Effects are concentration-dependent — pro-inflammatory at high levels.
  • Human dosing data is limited; cycle conservatively.

How This Works

LL-37 disrupts microbial membranes to kill bacteria, fungi and some viruses, neutralises endotoxin (LPS), and breaks down biofilms. Beyond antimicrobial action it modulates the immune response — recruiting immune cells, promoting angiogenesis and re-epithelialisation in wounds, and tuning inflammatory signalling. Its activity sits at the interface of infection defence and tissue repair.

Potential Benefits & Side Effects

Reported in research
  • Broad antimicrobial and antibiofilm activity
  • Endotoxin (LPS) neutralisation
  • Wound healing and re-epithelialisation
  • Immunomodulation and angiogenesis
Possible considerations
  • Injection-site reactions
  • Pro-inflammatory at high concentrations
  • Limited human dosing data
  • Context-dependent immune effects

Lifestyle Factors

  • Adequate hydration and 7–9 h of sleep are standard controls in most research protocols.
  • Consistent dose timing improves the reliability of any self-tracked endpoints.
  • Maintain a clean, sterile workflow for every draw to avoid contamination.

Injection Technique

  1. 1Wash hands, then prep the vial top and the target site with separate alcohol swabs.
  2. 2Pinch a subcutaneous skin fold (abdomen, ~2 inches from the navel) and insert at 45–90°.
  3. 3Depress the plunger slowly over 3–5 seconds, hold 5 seconds, then withdraw.
  4. 4Rotate sites each administration and dispose of the syringe in a sharps container.

Frequently Asked Questions

Third-party HPLC testing

CG Labz Verified Batches

No published batches yet.

Research Disclaimer

All compounds are supplied strictly for laboratory research. Dosing figures below summarize ranges reported in published preclinical and clinical literature for reference purposes only. CG Labz does not provide medical advice or individualized dosing recommendations.

Peer-reviewed literature

References

  1. [1] Journal of Immunology
    Vandamme D. et al. A comprehensive summary of LL-37.
    View Source