LL-37
The only antimicrobial peptide of the cathelicidin family found in humans. Acts as a first line of innate immune defense against bacteria, viruses, and fungi. Researched for antibiotic-resistant infections and immune modulation.
Last updated:: 06/04/2026
Research Status
ANVISA (Brazil)
Not regulated
FDA (USA)
Not regulated
EMA (Europe)
Not regulated
Mechanism of Action
LL-37 is a 37-amino acid peptide cleaved from the precursor protein hCAP18. It has direct antimicrobial activity — it disrupts bacterial membranes by forming pores. It also acts as an immunomodulator, recruiting immune cells, stimulating angiogenesis, and promoting wound healing. Naturally produced by neutrophils, macrophages, and epithelial cells.
Study Protocols
Dosages and regimens used in published clinical studies. This does not constitute a medical prescription.
Infecções / imunomodulação
Subcutânea (SC) ou TópicaCatelicidina antimicrobiana humana. Ação contra bactérias, fungos e biofilmes. Uso tópico em úlceras venosas mostrou cicatrização acelerada.
Benefits
Broad-spectrum antimicrobial activity
ProvenDemonstrated activity against gram-positive and gram-negative bacteria, enveloped viruses, and fungi in vitro. Active against bacterial biofilms.
Immunomodulation
Under researchRecruits immune cells, modulates inflammation, and promotes wound healing. Phase 1/2 clinical studies for venous ulcers showed positive results.
Risks and Side Effects
Toxicity at high doses
Moderate(Dose-dependent)At high concentrations, LL-37 can be cytotoxic to human cells (the same membrane-disrupting mechanism it uses against bacteria).
Internet vs. Science
What people say online compared to the actual scientific evidence.
Natural antibiotic that replaces medications
Partially trueWhat they claim
LL-37 naturally kills bacteria, viruses, and fungi — it can replace antibiotics.
Actual evidence
It has real and proven antimicrobial activity in vitro, but the concentrations needed in vivo are difficult to achieve without toxicity. It does not replace antibiotics for established infections. Research is focused on topical use for wounds.
| Claim | O que dizem | Evidência real | Verdict |
|---|---|---|---|
| Natural antibiotic that replaces medications | LL-37 naturally kills bacteria, viruses, and fungi — it can replace antibiotics. | It has real and proven antimicrobial activity in vitro, but the concentrations needed in vivo are difficult to achieve without toxicity. It does not replace antibiotics for established infections. Research is focused on topical use for wounds. | Partially true |
Important notice
This content is strictly informational and educational, based on published scientific research. It does not constitute medical advice, prescription, or encouragement to use any substance. Always consult a qualified physician before starting any treatment.
How to Obtain
This compound can be prepared by licensed compounding pharmacies with a valid prescription. Consult a physician first.