Antimicrobial peptide (cathelicidin) · Also known as Cathelicidin, hCAP18 active fragment
The only human cathelicidin antimicrobial peptide, a 37-amino-acid peptide that serves as a frontline component of innate immune defense. It directly kills bacteria, viruses, and fungi while also modulating immune and inflammatory responses.
LL-37 is the active fragment of the human cathelicidin precursor protein hCAP18 and plays a critical role in the body’s first line of defense against infection. It has demonstrated potent antimicrobial activity against both Gram-positive and Gram-negative bacteria, including drug-resistant strains like MRSA and VRE, as well as antiviral and antifungal properties. Beyond direct pathogen killing, LL-37 promotes wound healing and modulates inflammatory responses. While it is a naturally occurring peptide with extensive in vitro and animal research, clinical application of synthetic LL-37 is still in early stages.
LL-37 carries a strong positive charge that attracts it to the negatively charged membranes of bacteria and other pathogens. Once it contacts a microbial membrane, its alpha-helical structure allows it to insert into and physically disrupt the membrane, essentially punching holes in the pathogen and killing it. This mechanism makes it effective against a broad range of organisms, including antibiotic-resistant strains, and makes it difficult for bacteria to develop resistance.
Beyond direct antimicrobial action, LL-37 functions as an immune signaling molecule. It acts as a chemoattractant, recruiting immune cells like neutrophils, monocytes, and T cells to sites of infection. It also modulates inflammation by neutralizing bacterial lipopolysaccharide (LPS) and stimulates wound healing by promoting cell migration and angiogenesis.
50-100 mcg/day
Week 1100-200 mcg/day
2-4 week cycles, 5 days on / 2 days offMost side effects tend to improve as your body adjusts.