← Peptide library
Immune & antimicrobial

LL-37

Also known as: Cathelicidin · CAP-18 fragment

A natural antimicrobial peptide studied for infection defense, wound healing, and immune modulation.

LL-37 at a glance

NameLL-37
Also known asCathelicidin, CAP-18 fragment
CategoryImmune & antimicrobial
TypePeptide
Sequence37-amino-acid cathelicidin-derived peptide
Typical dose~100 mcg (varies)
FrequencyVaries
RouteSubcutaneous injection
Half-lifeShort.

Overview

LL-37 is part of the body’s innate immune defense — a naturally occurring peptide that can disrupt bacteria, fungi, and viruses directly while also shaping the immune and healing response. Research spans chronic infections, biofilms, and wound repair.

How it’s thought to work

  • Directly disrupts microbial membranes (broad antimicrobial action).
  • Modulates immune signaling and supports wound healing and angiogenesis.

Researched uses

  • Antimicrobial and biofilm research
  • Wound healing and immune modulation

Commonly cited protocol

Typical dose~100 mcg (varies)
FrequencyVaries
RouteSubcutaneous injection
NotesResearch dosing; can cause local reactions.

Reconstitution

Often a 5 mg vial. 5 mg with 2 mL water = 2.5 mg/mL, so 100 mcg = 4 units on a U-100 syringe.

LL-37 dosage calculator

The calculator below is pre-filled with LL-37’s commonly cited vial size and dose. Adjust the vial amount, bacteriostatic water, or dose to match your own vial — it will show the exact insulin-syringe units to draw, the concentration, and how many doses the vial holds.

mg
100 mcg = 0.1 mg
mL
How much water you add is your choice — it doesn’t change your dose, only how many units you draw. Common:
Draw to
10 units
= 0.1 mL on a 1 mL (100 units) syringe
010203040506070809010010 ufill to the 10 u line on a 100-unit barrel
Concentration
1 mg/mL
Per unit
10 mcg/u
Doses per vial
50 × 100mcg
Volume
0.1 mL
📋 In plain English

Add 5 mL of bacteriostatic water to your 5 mg vial. That gives you about 50 doses of 100 mcg. For each dose, draw 10 units into a 100-unit insulin syringe.

See the full LL-37 dosing chart (units for every dose & water amount), or open the full peptide calculator →

Cautions

  • Not approved for human use.
  • Can cause injection-site irritation/inflammation.
  • At high levels it may have pro-inflammatory effects.

LL-37 FAQ

What is LL-37?

A natural antimicrobial peptide studied for infection defense, wound healing, and immune modulation.

How does LL-37 work?

Directly disrupts microbial membranes (broad antimicrobial action). Modulates immune signaling and supports wound healing and angiogenesis.

What is LL-37 used for?

Antimicrobial and biofilm research; Wound healing and immune modulation.

What is a typical LL-37 dose?

~100 mcg (varies), Varies, Subcutaneous injection. This is a commonly cited figure for context only, not medical advice.

How do you reconstitute LL-37?

Often a 5 mg vial. 5 mg with 2 mL water = 2.5 mg/mL, so 100 mcg = 4 units on a U-100 syringe.

What is the half-life of LL-37?

Short.

⚠️ Educational reference only — not medical advice. These compounds are largely research chemicals not approved for human use in most countries. Nothing here is a recommendation to obtain or administer any substance. Consult a qualified clinician.