A to Z / Immune
LL-37
Also known as cathelicidin, hCAP18.
Best known for The body's own antimicrobial peptide, discussed for chronic infection
Evidence★☆☆☆☆
Safety dataLargely unknown
Route Injectable · nebulised · topical
United StatesNot approved
AustraliaNot listed by name; unapproved therapeutic good
as at 16 September 2026
What it is
LL-37 is the only human cathelicidin: a 37-amino-acid antimicrobial peptide produced by immune cells and epithelial tissue as part of innate immunity. It is a well-studied part of how the body fights infection. As an administered therapy it is still at the laboratory stage and is not approved anywhere.
What the full entry covers
The book carries the rest of this entry:
- Where the research stands, with every claim cited
- What people commonly ask, and what the research shows so far
- Dosing in four labelled bands, described and not recommended
- Side effects, serious risks, cautions and interactions
- Questions to discuss with your doctor
- How it compares with KPV, VIP, Thymosin Alpha-1, Thymulin
Related entries
A certificate of analysis tells you what is in a vial. The evidence rating above tells you whether the compound has been shown to work in humans. Neither answers the other's question. How to read a certificate of analysis.
This page describes what is known and not known about LL-37. It is not medical advice and not a recommendation to use it.