LL-37
Aliases: Cathelicidin LL-37 · hCAP-18 fragment
Last verified: 2026-09-23
The short version
The only human cathelicidin — an innate-immunity antimicrobial peptide. Broad spectrum against bacteria, viruses and biofilms; modulates inflammation and healing. Key fact: Human data are limited: small trials or case-series reports exist, without large randomized studies. Extensive preclinical work (biofilms, sepsis); early clinical attempts for leg ulcers and atypical infections. Status: research chemical. Not approved; research chemical. WADA: falls under S0.
Identity & type
- Molecular type
- peptide
- Origin
- The only human cathelicidin — an innate-immunity antimicrobial peptide.
Mechanism of action
Destabilizes microbial membranes; immunomodulatory via FPRL1, P2X7 and TLR pathways; immune-cell chemotaxis.
not confirmed in humans
Dosing & routes
Official / clinical context
No approved official document exists for LL-37. Any protocols mentioned are to be read as information, not as a recommendation.
Regulator-approved labeling and published study designs — never a recommendation.
Community-reported practice
Experimental: 50–100 mcg/day SC; topically for wounds. Antimicrobial effects reported for stubborn (biofilm) infections, but with marked injection reactogenicity; the community is cautious about autoimmune risks.
Unverified self-reports. Not medical advice. Not endorsement.
Expected effects (community)
Antimicrobial effects reported for stubborn (biofilm) infections, but with marked injection reactogenicity; the community is cautious about autoimmune risks.
Protocol — official vs community
Official / label
No approved product. Studied topically for wound infection contexts.
Duration: Study use only.
Human cathelicidin — broad antimicrobial peptide with a real (but narrow) research record.
Community (anecdotal)
Topical use in chronic-wound and acne communities; injectable use is rare and unprotocolized.
- Cycle:
- Topical: until resolution.
- Break:
- N/A.
The one gray-market peptide where the safer community practice (topical) is also the better-evidenced one.
Human evidence
Human data are limited: small trials or case-series reports exist, without large randomized studies. Extensive preclinical work (biofilms, sepsis); early clinical attempts for leg ulcers and atypical infections.
Preclinical evidence
Extensive preclinical work (biofilms, sepsis); early clinical attempts for leg ulcers and atypical infections.
Known risks
- Pro-inflammatory reactions at higher doses; linked to psoriasis when dysregulated.characterized
- Unregulated injectable supply — sterility, purity and accurate dose not assuredtheoretical
Teal: characterized in clinical/labeling contexts. Amber: theoretical or reported outside controlled settings.
Unknowns & evidence gaps
- Long-term human safety
- Optimal dose and pharmacokinetics
Frequently asked questions
References
Systematic references are being expanded; verify sources directly before any decision.