LL-37
LL-37 is the active form of human cathelicidin—an antimicrobial host-defense peptide studied in mucosal immunity and microbiome research.
What is LL-37?
LL-37 is the active form of human cathelicidin—an antimicrobial host-defense peptide studied in mucosal immunity and microbiome research. It is not a typical retail supplement or cosmetic INCI ingredient. Most discussion is in immunology literature (skin barrier, gut lining, infection defense)—not anti-aging serum marketing.
Where you will see LL-37
On product labels, look for the INCI name in the full ingredient list—not just front-of-pack nicknames. Concentration, formula pH, and what else is in the bottle all change how a peptide behaves on skin or hair.
Why LL-37 matters in research
Cathelicidins are part of innate immunity. LL-37 can modulate inflammation and microbial balance at mucosal surfaces. Topical or oral supplement products claiming “LL-37” usually lack the same evidence base as pharmaceutical development programs.
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Common questions
What does LL-37 mean?
LL-37 is the active form of human cathelicidin—an antimicrobial host-defense peptide studied in mucosal immunity and microbiome research. It is not a typical retail supplement or cosmetic INCI ingredient. Most discussion is in immunology literature (skin barrier, gut lining, infection defense)—not anti-aging serum marketing.
Is LL-37 an INCI ingredient name?
Sometimes. Brands use nicknames on the front label and INCI names on the back. Search our directory with either form to find the matching peptide page.