This page is provided for research and educational purposes only and does not provide medical advice, diagnosis, treatment recommendations, dosing instructions, or instructions for human use. Research findings should be interpreted within the population, model, formulation, route, outcomes, and study design reported by each cited source.
LL-37 (5 mg Vial)
LL-37 is a 37-amino-acid peptide derived from human cathelicidin (hCAP18)[4]. This overview summarizes preclinical infection research and topical wound studies, including their limitations[3][4][5]. Findings from topical formulations do not establish the safety or effectiveness of injected LL-37.
Quick Reference
What is LL-37?
LL-37 is a 37-amino-acid peptide derived from human cathelicidin (hCAP18)[4]. Researchers have examined it in a mouse sepsis model[3] and in topical formulations for venous leg ulcers and diabetic foot ulcers[4][5]. These studies concern specific experimental models, formulations and populations; they do not establish a personal administration protocol.
Storage Instructions
Proper storage preserves peptide quality[6][7].
• Lyophilized: Store at −20 °C (−4 °F) in dry, dark conditions; stable ~24 months.
• Reconstituted: Refrigerate at 2–8 °C (35.6–46.4 °F) for up to 4 weeks; frozen at −20 °C (−4 °F) for up to 6 months.
• Allow vials to reach room temperature before opening to reduce condensation uptake.
How is LL-37 studied?
LL-37 exerts both direct and indirect antimicrobial effects. Its amphipathic, cationic α-helical structure (net +6 charge) allows it to preferentially bind and disrupt negatively charged microbial membranes[2]. Beyond direct killing, LL-37 modulates host immunity: in murine sepsis models, it induced neutrophils to release microvesicles rich in antimicrobial proteins, lowering bacterial burden and improving survival[3]. LL-37 can also bind bacterial lipopolysaccharide (LPS) and block its interaction with CD14/TLR4, reducing endotoxin-triggered TNF release and neutrophil apoptosis[2]. These combined mechanisms help explain its potential in infection control and tissue-repair contexts.
What does the research report about LL-37?
Observations from preclinical and clinical literature.
• In a randomized trial of 148 patients with hard-to-heal venous leg ulcers, topical LL-37 did not significantly improve healing in the overall cohort compared with placebo. A post hoc finding in patients with larger wounds requires confirmation.[4]
• A randomized study of topical LL-37 cream in mildly infected diabetic foot ulcers reported greater improvement in a granulation index during the four-week study. It did not demonstrate reductions in IL-1α, TNF-α or aerobic bacterial colonization. These findings concern that topical formulation and study population.[5]
• Broad-spectrum antimicrobial action helps clear infections; in experimental sepsis models, LL-37 treatment reduced bacterial loads and mortality[3].
• Safety findings must be reported for the formulation and route actually studied. Topical wound studies cannot establish safety for injected LL-37.
Research Limitations / Risk Notes
The cited human studies evaluated topical LL-37 formulations for specific wound conditions. They do not establish the safety or effectiveness of subcutaneous LL-37 or provide a personal administration protocol.
Important Note
This content is provided for scientific research and educational purposes only. It does not provide medical advice, diagnosis, treatment, dosing, or administration instructions. The compounds discussed may be investigational and are not presented as approved for human use.
