RFK JR. ANNOUNCEMENT · FEB 27 2026 · 14 PEPTIDES RETURN TO CATEGORY 1DATABASE UPDATED · 847 NEW PUBMED CITATIONS THIS WEEKRETATRUTIDE · GRADE B EVIDENCE · 4 NEW CLINICAL TRIALSCOA SCANS · 2,341 BATCHES VERIFIED BY COMMUNITY THIS MONTHFDA ENFORCEMENT · PEPTIDE SCIENCES SHUTDOWN · MAR 2026GLP-1 DIRECTORY · 47 VERIFIED TELEHEALTH CLINICSRFK JR. ANNOUNCEMENT · FEB 27 2026 · 14 PEPTIDES RETURN TO CATEGORY 1DATABASE UPDATED · 847 NEW PUBMED CITATIONS THIS WEEKRETATRUTIDE · GRADE B EVIDENCE · 4 NEW CLINICAL TRIALSCOA SCANS · 2,341 BATCHES VERIFIED BY COMMUNITY THIS MONTHFDA ENFORCEMENT · PEPTIDE SCIENCES SHUTDOWN · MAR 2026GLP-1 DIRECTORY · 47 VERIFIED TELEHEALTH CLINICS
Healing

LL-37

Also known as: Cathelicidin · CAP18

Antimicrobial peptide with wound healing, immune modulation, and anti-biofilm properties.

B
Grade B
Human observational studies
Human studies30
PubMed citations30
Typical dose50 mcg – 200 mcg
Routesubcutaneous, topical, intramuscular
Regulatory (US)Compounding legal
Last verifiedyesterday
TL;DR · 30-second summary
  • Broad-spectrum antimicrobial activity
  • Disrupts bacterial biofilms
  • Promotes wound healing and angiogenesis
  • Immune modulation without excessive inflammation

Mechanism of action

Human cathelicidin antimicrobial peptide. Disrupts bacterial membranes, modulates immune response, promotes angiogenesis and wound healing, and breaks down bacterial biofilms.

Evidence summary

30
Human studies
30
PubMed citations
0
Clinical trials
B
Evidence grade

Endogenous human peptide with extensive research. Clinical trials for wound healing and infections. Topical formulations in development.

Dosing protocols

Educational information only. Consult a licensed provider before using any peptide.
Dose range
50 mcg – 200 mcg

Topical or local injection: 50-200mcg. Systemic use experimental. Often used for chronic infections.

Administration routes
subcutaneoustopicalintramuscular

Side effects & safety

Reported side effects
Injection site reactionsPossible immune stimulation
Contraindications
  • Autoimmune conditions (theoretical)
  • Pregnancy

Interactions

No documented drug interactions on file.

Regulatory status

United States
Not FDA approved

Not FDA approved. Research peptide.

Compounding
Permitted

Available through compounding pharmacies with valid prescription.

Regulatory data last verified 4/17/2026

Citations

PMID 36707289Ruiz-Tagle C, Romero F et al. · Vitamin D and cathelicidin levels and susceptibility to Mycobacterium tuberculosis infection acquisition in household contacts.Enfermedades infecciosas y microbiologia clinica (English ed.) (2026)HumanPMID 40612001Cerps S, Ramu S et al. · Antimicrobial peptide LL-37 increases rhinovirus-induced interferon β expression in human airway epithelial cells through a Ca2+-dependent mechanism.Biochemistry and biophysics reports (2025)HumanPMID 41270816Neshani A, Zare H et al. · Decoding LL-37: Structure and antimicrobial mechanisms against microbial threats.Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases (2025)HumanPMID 38972467Esposito TVF, Rodríguez-Rodríguez C et al. · Biodistribution of the cationic host defense peptide LL-37 using SPECT/CT.European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V (2024)HumanPMID 38642493Aidoukovitch A, Bankell E et al. · Vitamin D triggers hCAP18/LL-37 production: Implications for LL-37-induced human osteoblast cytotoxicity.Biochemical and biophysical research communications (2024)HumanPMID 37090695Zhang Q, Ul Ain Q et al. · Role of antimicrobial peptide cathelicidin in thrombosis and thromboinflammation.Frontiers in immunology (2023)HumanPMID 36614313Amagai R, Takahashi T et al. · The Antimicrobial Peptide Cathelicidin Exerts Immunomodulatory Effects via Scavenger Receptors.International journal of molecular sciences (2023)HumanPMID 35954305Radic M, Muller S · LL-37, a Multi-Faceted Amphipathic Peptide Involved in NETosis.Cells (2022)HumanPMID 36497142Bhusal A, Nam Y et al. · Cathelicidin-Related Antimicrobial Peptide Negatively Regulates Bacterial Endotoxin-Induced Glial Activation.Cells (2022)HumanPMID 36413063Jiang X, Yang C et al. · Nanomolar LL-37 induces permeability of a biomimetic mitochondrial membrane.Nanoscale (2022)HumanPMID 35291606Nikpoor M, Lohrasbi-Nejad A et al. · Heterologous Expression and Functional Characterization of CAP18 from Oryctolagus cuniculus.Reports of biochemistry & molecular biology (2022)HumanPMID 34637839Silva-Carvalho AÉ, Cardoso MH et al. · Dissecting the relationship between antimicrobial peptides and mesenchymal stem cells.Pharmacology & therapeutics (2022)HumanPMID 34651203Mohanty S, Kamolvit W et al. · HIF-1 mediated activation of antimicrobial peptide LL-37 in type 2 diabetic patients.Journal of molecular medicine (Berlin, Germany) (2022)HumanPMID 36335830Porto WF, Alencar SA · In silico assessment of missense point mutations on human cathelicidin LL-37.Journal of molecular graphics & modelling (2022)HumanPMID 33627652Minns D, Smith KJ et al. · The neutrophil antimicrobial peptide cathelicidin promotes Th17 differentiation.Nature communications (2021)HumanPMID 34680791Simonetti O, Cirioni O et al. · Efficacy of Cathelicidin LL-37 in an MRSA Wound Infection Mouse Model.Antibiotics (Basel, Switzerland) (2021)HumanPMID 33347965Oliveira PN, Courrol DS et al. · Inactivation of the antimicrobial peptide LL-37 by pathogenic Leptospira.Microbial pathogenesis (2021)HumanPMID 32509872Yang B, Good D et al. · Significance of LL-37 on Immunomodulation and Disease Outcome.BioMed research international (2021)HumanPMID 29589544Chieosilapatham P, Ikeda S et al. · Tissue-specific Regulation of Innate Immune Responses by Human Cathelicidin LL-37.Current pharmaceutical design (2019)HumanPMID 30980360Wang G, Narayana JL et al. · Design of Antimicrobial Peptides: Progress Made with Human Cathelicidin LL-37.Advances in experimental medicine and biology (2019)Human

Showing 20 of 30 papers. View all on PubMed →