Not FDA approved and sold as a research chemical. This page is educational information only. It is not medical advice and not a recommendation to use anything.

IndexedBuilt automatically from public databases on 2026-09-30. Not yet hand-reviewed by PLOBT.How this works →

LL-37

Not FDA approved

Antimicrobial host defense peptide

Also known as: cathelicidin, CAP-18, ropocamptide, Cap-18, cathelicidin LL-37, CAP18, Antibacterial peptide LL-37, antimicrobial peptide LL-37, LL-37 antibacterial peptide

Evidence score

53/ 100

Moderate evidence

A real evidence base, with gaps

Regulatory standing. Sold as a research chemical, not approved
Limited human data. Some human data exists, not conclusive
Registered human trials. 20 registered studies on ClinicalTrials.gov, most advanced Phase 3
1 cited source. Includes primary / regulatory sources

Computed with the same four public criteria as every profile. The human-evidence grade on an indexed profile is set automatically and may change when it is hand-reviewed. It is not a safety score, not a purity rating, and not medical advice, and not a claim that this compound treats, cures, or prevents any condition.

What it is

LL-37 is a 37 amino acid peptide, the only human member of the cathelicidin family, cleaved from the precursor protein hCAP-18. It is produced by immune and skin cells and is thought to act by disrupting microbial membranes and by modulating inflammation, immune signaling, and wound repair.

What the evidence shows

Automatic summaryLimited human data

LL-37 is not FDA approved for any use. It is widely studied in the lab, and about 20 registered human trials exist, reaching Phase 3 for uses such as chronic leg ulcers, but no conclusive human benefit has been established.

Key facts

Molecular formula

C205H340N60O53

Molecular weight

4493 g/mol

Registered human trials

Live from ClinicalTrials.gov, refreshed daily.

20registered studies

Phase 3most advanced phase

12completed (sample)

1recruiting (sample)

Effect of High-Dose Vitamin D3 in Smokers and Non-Smokers With and Without HIV

Phase 1TerminatedNCT03270709

Evaluation of 25(OH)D3 and LL-37 Levels in Periimplant Sulcus Fluid

Not Yet RecruitingNCT07280754

Effects of Aminocaproic Acid (ACA) on Rosacea-specific Inflammation

Early Phase 1CompletedNCT01398280

Intratumoral Injections of LL37 for Melanoma

Phase 2CompletedNCT02225366

Published literature

Live from Europe PMC. This is how much has been published, not how much is proven in humans.

2,675papers referencing LL-37

Endogenous antimicrobial peptides and skin infections in atopic dermatitis.

N Engl J Med2002

Netting neutrophils induce endothelial damage, infiltrate tissues, and expose immunostimulatory molecules in systemic lupus erythematosus.

J Immunol2011

LL-37, the neutrophil granule- and epithelial cell-derived cathelicidin, utilizes formyl peptide receptor-like 1 (FPRL1) as a receptor to chemoattract human peripheral blood neutrophils, monocytes, and T cells.

J Exp Med2000

Innate antimicrobial peptide protects the skin from invasive bacterial infection.

Nature2001

Sources

Risks, side effects and study doses are only published on hand-reviewed profiles. Want this one reviewed, or spotted something wrong? Tell us.