Antimicrobial & Immune Defense. LL-37 is the only cathelicidin-derived antimicrobial peptide in humans. Produced by immune cells and epithelial cells, i...
LL-37 is the only cathelicidin-derived antimicrobial peptide in humans. Produced by immune cells and epithelial cells, it is present in sweat, saliva, and breast milk. It plays a crucial role in innate immune defense and has significant interest in the CIRS and mold illness communities.
LL-37 disrupts microbial membranes through electrostatic interactions, creating lethal pores. Beyond direct antimicrobial activity, it serves as an immunomodulator — recruiting immune cells, promoting wound healing, influencing angiogenesis, and modulating inflammatory cytokines. It also has documented anti-biofilm activity relevant to chronic infections.
Important: The evidence base for LL-37 varies by application. Many findings are from preclinical (animal or in vitro) studies. Large-scale human clinical trials may not be completed. Always evaluate the quality of evidence before drawing conclusions.
Limited human safety data. Reported anecdotal effects include injection site reactions and flu-like symptoms. At high concentrations, LL-37 can be cytotoxic to human cells — dosing is important.
LL-37 remains on the FDA's Category 2 (restricted) list. Limited human safety data prevents reclassification. Available as a research chemical but cannot be legally compounded by 503A pharmacies.
These verified suppliers carry LL-37 with third-party COAs and US-based shipping.