LL-37
REC PPT-LL-37 // REV 2026-10-04 // assessment changes are logged, never silent
Human antimicrobial peptide. Important biology, limited therapeutic human data.
What it is
The only human cathelicidin antimicrobial peptide, part of innate immune defence.
What it does
Disrupts microbial membranes and participates in immune signalling and wound repair.
Does it work?
Well characterised as a component of human immunity. Therapeutic administration is a separate matter with much thinner clinical evidence, and immune peptides can act in both directions depending on context.
Claims vs data
Each marketing claim, tagged by what the evidence actually supports.
| Kills microbes in laboratory models | preclinical only |
| A core component of human innate immunity | supported |
| Treats chronic infections when injected | weak evidence |
Reference figures
Quoted from published reference material. These are not Peptuity recommendations.
molecular data — PubChem CID 16198951
The evidence, counted
Live counts from Europe PMC and ClinicalTrials.gov.
3,768 publications indexed, including 40 randomised controlled trials. 44 interventional studies registered. This is a well-tested compound.
SRC // EUROPE PMC + CTGOV // "cathelicidin LL-37" // FETCHED 2026-10-04 // 3,768 RECORDS
Most-cited literature
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[01]
APD3: the antimicrobial peptide database as a tool for research and education
Wang G, Li X, Wang Z. · Nucleic Acids Res 2016 · 1776 citations · DOI 10.1093/nar/gkv1278
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[02]
Peptide antimicrobial agents
Jenssen H, Hamill P, Hancock RE. · Clin Microbiol Rev 2006 · 1714 citations · DOI 10.1128/cmr.00056-05
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[03]
Polymyxins: Antibacterial Activity, Susceptibility Testing, and Resistance Mechanisms Encoded by Plasmids or Chromosomes
Poirel L, Jayol A, Nordmann P. · Clin Microbiol Rev 2017 · 1151 citations · DOI 10.1128/cmr.00064-16
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[04]
Antimicrobial Peptides: Classification, Design, Application and Research Progress in Multiple Fields
Huan Y, Kong Q, Mou H, Yi H. · Front Microbiol 2020 · 1048 citations · DOI 10.3389/fmicb.2020.582779
Regulatory status
Formal, dated regulatory actions.
WADA — Prohibited List 2026
Prohibited in sport — WADA S0 (substance without any health-authority approval)
Common questions
What is LL-37 in the body?
The only human cathelicidin — an antimicrobial peptide of innate immunity that disrupts microbial membranes and signals to immune cells.
If it is natural, why not inject more?
Because immune peptides act in both directions. Elevated LL-37 is itself implicated in conditions like psoriasis and rosacea — more is not automatically better.
Is there human therapeutic evidence?
Limited — early wound-healing work exists, but nothing approaching approval for the systemic uses it is marketed for.