LL-37

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LL-37 (also known as Cathelicidin Antimicrobial Peptide) is a naturally occurring host-defense peptide produced by the CAMP gene in humans.

It is part of the innate immune system, providing broad protection against bacteria, viruses, and fungi, while also playing a role in wound healing, inflammation control, and tissue regeneration.

In research, LL-37 is studied for its immunomodulatory, antimicrobial, and regenerative properties, particularly in the fields of skin health, respiratory defense, and chronic inflammation.

LL-37 exerts its biological effects through multiple immune and cellular pathways, combining antimicrobial action with immune system modulation.

Key mechanisms observed in research:

1. Destroys microbial membranes — broad-spectrum antibacterial and antiviral activity
    
2. Modulates immune response — balances pro- and anti-inflammatory cytokines
    
3. Promotes wound healing — accelerates angiogenesis and re-epithelialization
    
4. Exerts anti-biofilm effects — disrupts bacterial biofilms resistant to antibiotics
    
5. Enhances tissue regeneration — recruits stem cells and growth factors to damaged sites

Antimicrobial

Effective against Gram-positive, Gram-negative bacteria, and viruses

Wound healing

Accelerated tissue repair and reduced infection risk

Immune regulation

Balanced inflammatory and cytokine signaling

Anti-biofilm activity

Inhibits bacterial colonization on wounds or implants

Regenerative research

Promoted angiogenesis and tissue remodeling

Injectable (subcutaneous/intradermal)

100–500 mcg

1–3× per week

Topical solution/cream (experimental)

0.1–0.5% concentration

Applied 1–2× daily

In vitro assays

1–10 μM

Concentration dependent 

• Cycle duration (research): 2–4 weeks
   
• Half-life: ~1 hour (short systemic duration, potent localized action)
   
• Synergistic research: Often evaluated with BPC-157, GHK-Cu, or Thymosin Beta-4 for wound-healing synergy