The Peptide Audit

What is LL-37?

Mostly animal & lab studiesImmune research · Last reviewed September 28, 2026

LL-37 is the only cathelicidin antimicrobial peptide made by the human body, named for its 37 amino acids beginning with two leucines.

How does LL-37 work?

It can disrupt bacterial membranes and also signals to immune cells, playing a role in the skin’s and gut’s first-line defenses.

What are researchers studying?

Where does the evidence stand?

Mostly animal & lab studies

Not approved by the FDA as a drug.

Quick facts

Research area
Immune
Also known as
LL37
Third-party lab results
1 published COAs →
Tested vendors tracking it
2 vendors →

Recent peer-reviewed research

The most relevant LL-37 studies from the last three years, via PubMed (U.S. National Library of Medicine).

  1. A Dual-Response DNA Origami Platform for Imaging and Treatment of Sepsis-Associated Acute Kidney Injury
    Advanced science (Weinheim, Baden-Wurttemberg, Germany) · 2025 Apr · PubMed ↗
  2. Targeted delivery of antimicrobial peptide LL-37 via ferritin fusion improves antibacterial and anti-inflammatory outcomes in a murine sepsis model
    International journal of biological macromolecules · 2026 Aug 31 · PubMed ↗
  3. Vitamin D and cathelicidin levels and susceptibility to Mycobacterium tuberculosis infection acquisition in household contacts
    Enfermedades infecciosas y microbiologia clinica (English ed.) · 2023 Oct · PubMed ↗
  4. Antiparasitic effect of peptoids against Cryptosporidium parvum
    Microbiology (Reading, England) · 2025 Oct · PubMed ↗
  5. The chemorepellent, SLIT2, bolsters innate immunity against Staphylococcus aureus
    eLife · 2023 Sep 29 · PubMed ↗

Compare LL-37

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This guide summarizes published research for educational purposes only. It is not medical advice and does not describe how to use LL-37. Citations link to PubMed and are listed for reference — we haven't reviewed or endorsed their findings. Products referenced on The Peptide Audit are sold by third parties for laboratory research use only and are not for human consumption.