What is it?

LL-37 is a naturally occurring human antimicrobial peptide derived from the cathelicidin protein hCAP18. It forms part of the body’s innate immune system and is found in immune cells, skin, airways, and other tissues.

How does it work?

LL-37 can disrupt the membranes of certain bacteria, viruses, and fungi while influencing immune signalling, inflammation, blood-vessel formation, and tissue repair. Its effects are highly context-dependent: it may reduce harmful microbes but can also promote inflammation or damage cells at excessive concentrations.

What is it good for?

Potential applications under investigation include:

• Supporting research into the body’s natural antimicrobial and immune defences.
• Disrupting certain bacterial biofilms in laboratory studies.
• Investigating wound healing and tissue repair.
• Serving as a possible foundation for developing new anti-infective treatments.

Summary (Pros and Cons)

Pros: Broad antimicrobial and anti-biofilm activity demonstrated in laboratory research; may support immune defence and wound repair.

Cons: Human evidence remains limited; excessive exposure may cause inflammation or cellular toxicity. Injectable LL-37 is experimental and lacks established dosing and long-term safety data.

General Overview

LL-37 is best viewed as a promising host-defence peptide rather than a proven antimicrobial treatment. Its ability to influence both microbes and the immune system makes it scientifically valuable, but those same complex effects require careful clinical study before routine therapeutic use.