LL-37

LL-37 is the only human cathelicidin-derived antimicrobial peptide. It is part of the innate immune system and has drawn research interest for a dual role: direct defense against microbes and modulation of the wider innate immune response. Reviews describe it as a multitask peptide with pleiotropic activity, and it is studied across several areas, including infection, inflammation, autoimmunity and cancer biology.

Research describes two main mechanisms. First, LL-37 interacts directly with microbial membranes and disrupts them, a mode of action distinct from conventional antimicrobial pathways. Second, it acts as a signaling molecule that recruits immune cells and shapes the inflammatory response to a challenge. This combination of direct membrane activity and immune signaling is a central theme in the published reviews of the peptide.

Published reviews have examined LL-37 antibiofilm properties, its roles in health and disease of the oral cavity, and its involvement in inflammatory bowel disease and systemic lupus erythematosus. Other work has explored its roles and mechanisms in cancer, as well as nanoantibiotic designs that attach membrane-active LL-37 to magnetic nanoparticles. Most of this literature is review-based or laboratory work rather than clinical trial data.

Human safety data are limited, and adverse events are not summarized in the cited studies. Laboratory research has reported LL-37-induced cytotoxicity in human osteoblasts, which was examined in connection with vitamin D-triggered hCAP18/LL-37 production. Reviews also discuss possible roles for LL-37 in cancer development and in the pathophysiology of systemic lupus erythematosus. These findings suggest that its biological effects depend on context.

Research protocols have used 100 to 500 mcg per administration by the subcutaneous route, once daily in the morning, in 4-week blocks followed by 4 weeks off. These figures describe what research protocols have used and are not a recommendation. Each CoreX order ships with a protocol guide for laboratory research reference. CoreX supplies LL-37 for laboratory research use only.