For research use only. Not for human consumption. Not medical advice — consult a licensed clinician.

Immune Modulator

LL-37

Also known as: Cathelicidin

LL-37 is the only human cathelicidin antimicrobial peptide — a 37-amino-acid peptide (starting with two leucines) cleaved from the hCAP-18 precursor. It has broad-spectrum antimicrobial activity and immunomodulatory roles, but is also implicated in the pathogenesis of autoimmune and inflammatory skin diseases including psoriasis, rosacea, and lupus. Not FDA-approved; research-use only.

Real-time market data

Pricing for LL-37

Live vendor pricing, normalized to $/mg so sizes compare fairly — fused with each seller's Merit trust score and latest independent COA purity. Prices refresh daily.

Independent evidence

COAs for LL-37

25 third-party tests across 8 vendors. Each card links to the full report.

All 25 COAs for LL-37 →
Measured purity 91.1%–99.9% across 18 COAs
Measured purity over time
Aggregated · 3rd-party listing
99.64 %
May 2026
Janoshik Analytical · HPLC

For

LL-37

by Verified Peptides· batch LL05260305C

Aggregated · 3rd-party listing
91.08 %
May 2026
Freedom Diagnostics

For

LL-37

by Real Peptides· batch Black Cap

Aggregated · 3rd-party listing
99.94 %
Mar 2026
Kovera Labs

For

LL-37

by Ion Peptide· batch LL375-03232026

Aggregated · 3rd-party listing
99.93 %
Jan 2026
Freedom Diagnostics · HPLC

For

LL-37

by Simple Peptide· batch L1-05-01162026-J

Aggregated · 3rd-party listing
99.93 %
Jan 2026
Freedom Diagnostics · HPLC

For

LL-37

by Simple Peptide· batch LL10-37011220236-J

Aggregated · 3rd-party listing
99.70 %
Jan 2026
Freedom Diagnostics · HPLC

For

LL-37

by MedGe Peptides· batch LL375LT12

Aggregated · 3rd-party listing
99.70 %
Jan 2026
Freedom Diagnostics · HPLC

For

LL-37

by MedGe Peptides· batch LL375LT12

Aggregated · 3rd-party listing
99.84 %
Jan 2026
Freedom Diagnostics · HPLC

For

LL-37

by Simple Peptide· batch LL37L2092025-J

Aggregated · 3rd-party listing
99.83 %
Dec 2025
BioRegen

For

LL-37

by Real Peptides

Aggregated · 3rd-party listing
99.65 %
Oct 2025
Chromate · HPLC

For

LL-37

by Mile High Compounds· batch LL3-005-MH-01

Aggregated · 3rd-party listing
99.80 %
Oct 2025
MDx BioAnalytical Laboratory · HPLC

For

LL-37

by BioLongevity Labs· batch 251549

Aggregated · 3rd-party listing
99.75 %
Oct 2025
Janoshik Analytical · HPLC

For

LL-37

by Skye Peptides· batch LL25-04-002

Aggregated · 3rd-party listing
99.95 %
Oct 2025
Freedom Diagnostics

For

LL-37

by Ion Peptide· batch LL5-1025

Aggregated · 3rd-party listing
99.50 %
Aug 2025
Freedom Diagnostics · HPLC

For

LL-37

by Simple Peptide· batch LL3708202025-J

Aggregated · 3rd-party listing
99.61 %
Jul 2025
Freedom Diagnostics · HPLC

For

LL-37

by Simple Peptide· batch LL3705072025-J

Aggregated · 3rd-party listing
99.94 %
Mar 2025
BioRegen · HPLC

For

LL-37

by BioLongevity Labs· batch cmojb7o9z01dakirxmbk61guw

Aggregated · 3rd-party listing
99.36 %
Mar 2025
Janoshik Analytical · HPLC

For

LL-37

by Skye Peptides· batch LL25-04-001

Aggregated · 3rd-party listing
99.64 %
Jan 2025
Janoshik Analytical · HPLC

For

LL-37

by Verified Peptides· batch 12-24-0105A

Aggregated · 3rd-party listing
Dec 2025

Purity not on file

BioRegen

For

LL-37

by Real Peptides

Aggregated · 3rd-party listing
Nov 2025

Purity not on file

BioRegen

For

LL-37

by BioLongevity Labs· batch 16-3-45954

Aggregated · 3rd-party listing
Oct 2025

Purity not on file

Janoshik Analytical

For

LL-37

by Skye Peptides· batch LL25-04-002

Aggregated · 3rd-party listing
Oct 2025

Purity not on file

Janoshik Analytical

For

LL-37

by Skye Peptides· batch LL25-04-002

Aggregated · 3rd-party listing
Apr 2025

Purity not on file

Janoshik Analytical

For

LL-37

by Skye Peptides· batch LL25-04-001

Aggregated · 3rd-party listing
Feb 2025

Purity not on file

Janoshik Analytical

For

LL-37

by Verified Peptides· batch 12-24-0105A

Research depth

31 citations indexed for LL-37

All research on LL-37 →

Study · 2026

Serine protease HtrA promotes <i>Campylobacter jejuni</i> intestinal colonization through degrading antimicrobial peptide LL-37

Campylobacter jejuni ( C. jejuni ) is a leading cause of human gastroenteritis worldwide and must overcome intestinal innate immunity, including antimicrobial peptide LL-37. However, how C. jejuni responds to LL-37 remains unclear. Here, we showed that C.

review · 2026

Overcoming LPS-mediated resistance in gram-negative pathogens: a review of LL-37 analogs and computational design strategies

The increasing incidence of antimicrobial resistance (AMR) in Gram-negative bacteria has become a significant global health issue, driven primarily by the structural and adaptive characteristics of lipopolysaccharide (LPS) in the outer membrane.

Study · 2026

Human cathelicidin peptide LL-37 compacts nucleic acids and alters neutrophil extracellular trap structure

The human cathelicidin host defense peptide LL-37 is expressed by many cell types, including neutrophils, macrophages, and epithelial cells, and forms complexes with nucleic acids that can have either beneficial or detrimental health effects.

review · 2026

LL-37: Biological Mechanisms and Emerging Therapeutic Applications in Intestinal Disease

Human cathelicidin peptide LL-37 is encoded by the CAMP gene and plays a key role in innate immunity. It maintains intestinal homeostasis through antibacterial, immunomodulation, and tissue repair functions.

Study · 2026

Cellulose-based hydrogel matrix enhances antimicrobial and biofilm-inhibitory responses of palatal mesenchymal stem cells

Mesenchymal stem cells (MSCs) have emerged as promising alternatives to fight drug-resistant bacterial infections.

Study · 2026

LL-37 Inhibits EV71 Infection by Upregulating STAC via the EGFR-ERK Signaling Pathway

LL-37, a 37-amino acid human-derived antimicrobial peptide, was shown in our earlier clinical study to shorten the negative conversion time of the Omicron BA.5.1.3 variant of SARS-CoV-2.