Research overview
What is LL-37?
LL-37 is a 37-residue peptide cleaved from the human cathelicidin precursor hCAP18. In experimental systems it has antimicrobial and immune-signaling activity. Natural expression does not imply that an externally sourced LL-37 vial is safe or effective.
What has research examined?
A phase IIb placebo-controlled trial enrolled 148 participants with hard-to-heal venous leg ulcers and evaluated LL-37 applied topically alongside compression care. It did not detect a significant healing difference in the full trial cohort. Findings from a topical formulation cannot be converted into an injected or systemic claim.
FDA warns of aggregation/impurity and immunogenicity concerns, insufficient human safety information, and nonclinical findings suggesting male-reproductive harm and protumorigenic effects in some tissues. This page gives no administration or preparation advice.
Research references
- HEAL LL-37 randomized trial in venous leg ulcersWound Repair and Regeneration
- Certain bulk substances that may present significant safety risksU.S. Food and Drug Administration
Calculation boundary
The cited clinical trial evaluated a defined topical LL-37 formulation, not a generic syringe-based research vial. FDA flags insufficient human safety information and nonclinical reproductive/tumor-related concerns for proposed compounded LL-37.