LL-37 — Vendor Pricing & Purity Guide
Research Overview
LL-37 is a 37-amino-acid antimicrobial peptide (AMP) and the only cathelicidin-derived peptide in humans. It is produced by immune cells, epithelial cells, and neutrophils as a first-line defense against bacterial, viral, and fungal infections. LL-37 is named for its two leading leucine residues and its 37-amino-acid length.
Beyond direct antimicrobial activity, LL-37 functions as a potent immunomodulator. It recruits immune cells to infection sites, promotes wound healing, neutralizes bacterial endotoxins (LPS), and modulates the adaptive immune response. It can directly disrupt bacterial cell membranes through its amphipathic alpha-helical structure — inserting into and permeabilizing lipid bilayers that make up bacterial outer membranes.
LL-37 has gained significant research interest in the context of antibiotic resistance. As bacteria develop resistance to conventional antibiotics, antimicrobial peptides like LL-37 offer an alternative mechanism that is inherently difficult for bacteria to resist — since resistance would require fundamental changes to membrane structure. Research into LL-37 and its derivatives represents a growing frontier in infectious disease and wound care.
Key Research Findings
- •Broad-spectrum antimicrobial activity against gram-positive bacteria, gram-negative bacteria, fungi, and enveloped viruses
- •Neutralized bacterial endotoxin (LPS), reducing sepsis-associated inflammation in animal models
- •Promoted wound healing through keratinocyte migration, angiogenesis, and immune cell recruitment
- •Disrupted biofilm formation — relevant for chronic wound infections and implant-associated infections
- •Demonstrated anti-cancer activity by selectively disrupting cancer cell membranes in vitro and in vivo
- •Modulated dendritic cell function, bridging innate and adaptive immune responses
- •Synergistic antimicrobial effect when combined with conventional antibiotics against resistant strains
Research Dosage Protocols
LL-37 is supplied as lyophilized powder and reconstituted with sterile water or bacteriostatic water. It is administered via subcutaneous injection in most research protocols.
Published research doses vary by application. Antimicrobial research typically uses concentrations of 1-50 μM in vitro. Animal wound healing studies have used topical application of 10-100 mcg per wound site.
LL-37 is a relatively large peptide (37 amino acids) and can be sensitive to degradation by proteases in serum. Research protocols studying systemic effects may need to account for its relatively short in vivo half-life. Topical and local administration provides higher concentrations at the target site.
For research reference only. Not medical advice. Not for human consumption.
Published Research (1 studies)
- [1]A comprehensive summary of LL-37, the factotum human cathelicidin peptide— Vandamme et al., 2012PMID: 22050882
Links go to PubMed (NIH National Library of Medicine). PeptideVerdict is not affiliated with these studies.
Price Comparison (14 products from 13 vendors)
| Vendor | Price | Stock |
|---|---|---|
| Paradigm Peptides | $35.00 $7.00/mg 5mg lyophilized | In Stock |
| Peptide Crafters | $50.00 $10.00/mg 5mg capsule | In Stock |
| Triumphant Labs | $62.00 $12.40/mg 5mg | In Stock |
| Polaris Peptides | $125.00 $12.50/mg 10mg lyophilized | In Stock |
| Swiss Chems | $71.99 $14.40/mg 5mg vial | In Stock |
| Skye Peptides | $74.00 $14.80/mg 5mg lyophilized | In Stock |
| Particle Peptides | $79.99 $16.00/mg 5mg lyophilized | In Stock |
| Biotech Peptides | $86.00 $17.20/mg 5mg vial | In Stock |
| Core Peptides | $89.00 $17.80/mg 5mg vial | In Stock |
| BioLongevity Labs | $94.97 $18.99/mg 5mg vial | In Stock |
| Peptide Sciences | $95.00 $19.00/mg 5mg lyophilized | In Stock |
| Triumphant Labs | $527.00 $105.40/mg 5mg | In Stock |
| Soma Chems | $79.99 vial | In Stock |
| Simple Peptide | $45.00 lyophilized | In Stock |
Frequently Asked Questions
What is LL-37?
LL-37 is the only human cathelicidin antimicrobial peptide. It provides broad-spectrum defense against bacteria, viruses, and fungi by disrupting their cell membranes. It also modulates immune function and promotes wound healing.
How does LL-37 kill bacteria?
LL-37 has an amphipathic alpha-helical structure that inserts into bacterial cell membranes, creating pores that disrupt membrane integrity. This physical mechanism is difficult for bacteria to develop resistance against, unlike conventional antibiotics.
Can bacteria develop resistance to LL-37?
Resistance to LL-37 is rare because it targets fundamental membrane structure. While some bacteria have evolved partial resistance mechanisms (surface charge modifications, protease secretion), complete resistance is inherently difficult. This makes AMPs valuable for antibiotic-resistance research.
Where can I buy LL-37 for research?
LL-37 is available from research peptide vendors. Compare pricing in the table above.