LL-37
LL-37 (Cathelicidin Antimicrobial Peptide)
Research Parameters
- Typical Dose Range
- 100 to 500 mcg daily subcutaneous (research standard). Topical formulations also used in research.
- Half-Life
- ~30 minutes (plasma); longer in tissue
- Administration Route
- Subcutaneous, Topical
Dosing information is for research purposes only and has not been evaluated by the FDA.
Your immune system has a built-in antibiotic called LL-37, and most people's bodies don't make enough of it. Production drops with age, with vitamin D deficiency, and with chronic inflammation, which is part of why all three conditions correlate with how often you get sick and how slowly you heal. Researchers study it because it kills infections conventional antibiotics can't touch, including biofilm-associated infections that show up after surgery, injury, or chronic inflammation.
If you've had a wound that won't heal, a gut issue that won't clear, or you keep catching every virus that goes around your gym, this is one of the peptides the research is looking at. Unlike conventional antibiotics, pathogens don't easily develop resistance to LL-37 because of how it works. That's why antibiotic resistance research has pushed this peptide significantly forward in the last decade.
For research purposes only.
Mechanism of Action
LL-37 is the only cathelicidin produced by the human body, a 37-amino-acid antimicrobial peptide that disrupts bacterial cell membranes directly rather than targeting specific bacterial metabolism. This membrane disruption mechanism is why pathogens struggle to develop resistance. It's dual-purpose: antimicrobial and immunomodulatory, with roles in wound healing and inflammation regulation.
Citations
Frequently Asked Questions
- What is LL-37 used for in research?
Research covers chronic and antibiotic-resistant infections, biofilm disruption, gut dysbiosis, and wound healing. It's a dual antimicrobial and immunomodulator. For research purposes only.
- How does LL-37 compare to conventional antibiotics?
Conventional antibiotics typically target a specific bacterial mechanism (cell wall, protein synthesis). LL-37 disrupts bacterial membranes directly, which is why pathogens struggle to develop resistance. Research interest has grown alongside antibiotic resistance concerns. For research purposes only.
- Why does LL-37 production drop with age?
Vitamin D signaling is a primary driver of cathelicidin expression, and vitamin D status declines with age. Chronic inflammation and certain medications also suppress endogenous LL-37 production. For research purposes only.