LL-37

Key Benefits#

• Broad-spectrum antimicrobial (bacteria, fungi, viruses)
• Promotes wound healing and angiogenesis
• Immune system modulation — enhances innate immunity
• Reduces LPS-mediated endotoxemia
• Anti-biofilm activity against resistant organisms
• Promotes tissue regeneration and keratinocyte migration
• May protect against sepsis

Mechanism of Action#

LL-37 is derived from the C-terminus of the human cathelicidin protein hCAP18. It inserts into microbial cell membranes causing pore formation and membrane disruption. Additionally it acts as a GPCR ligand (FPRL1/FPR2), Toll-like receptor modulator, and can bind and neutralize lipopolysaccharide (LPS), preventing endotoxin-mediated inflammation. In host cells it promotes keratinocyte migration, angiogenesis, and wound closure.

Dosing Protocols#

Side Effects#

• Injection site redness and irritation
• Mild inflammatory response at injection site
• Potential pro-inflammatory at high doses
• Rare: fever or flu-like symptoms at initiation

Contraindications#

Use with caution in autoimmune conditions. High doses may paradoxically increase inflammation. Not recommended during acute cytokine storm.

Storage#

Lyophilized: store at -20°C. Reconstituted: 4°C, use within 2–4 weeks. Protect from light and repeated freeze-thaw cycles.

Featured In Stacks#

1. 1.
   Analysis of Antimicrobial Peptide Expression Under Acute and Chronic Alcohol Exposure: A Cross-Sectional Study and a Systematic Review of the Literature

   Rojas-Pirela M, Herrera-Flores C, Costa-Alba P, Salete-Granado D, Aguilar ML, Puertas-Miranda D et al. · International journal of molecular sciences · 2026PubMed Verified

2. 2.
   Host Defense Antimicrobial Peptides (HDPs) as Regulators of Hemostasis and Vascular Biology

   Aguilar-Ruiz SR, Sánchez-Peña FJ, Rodríguez-Magadán HM, Domínguez-Martínez MA, Bernardino-Hernández HU, Aquino-Domínguez AS · Biomolecules · 2026ReviewPubMed Verified

3. 3.
   Engineering Smart Bimetallic Ionic-Site MOF Nanozyme Nanocomposites for Microenvironment-Responsive Dynamic Therapy of Periapical Periodontitis

   Pan MM, Ye WH, Zhang RZ, Hu JX, Xie Y, Wang M et al. · ACS nano · 2026PubMed Verified

4. 4.
   Investigation of Regulation and Binding Patterns of the Human Cathelicidin Peptide LL-37 in Complexation with Nucleic Acids, and its Impact on Neutrophil Extracellular Traps

   Zielke C, Rad B, Nielsen JE, Li J, Pimcharoen S, Sawant M et al. · bioRxiv : the preprint server for biology · 2026PubMed Verified

5. 5.
   Modulation of LPS-associated virulence activity for reduction of periodontal inflammatory burden

   Dong A, Lehto M, Putaala J, Paju S, Pussinen P, Zaric S · Frontiers in microbiology · 2026PubMed Verified

6. 6.
   Disturbed regulation of immunothrombosis in cerebral ischemia associated with SARS-CoV-2 infection

   Plem R, de Buhr N, Imker R, Akhdar S, Meurer M, Falk CS et al. · Frontiers in immunology · 2026PubMed Verified

7. 7.
   Common Biomarkers in Chronic Obstructive Pulmonary Disease and Bronchopulmonary Dysplasia: A Narrative Review of an Intriguing Interplay

   Gambadauro A, Xerra F, Chirico V, Rulli I, Cacciola A, Mallamace R et al. · International journal of molecular sciences · 2026ReviewPubMed Verified

8. 8.
   Immunomodulatory Effects of the Antimicrobial Peptide KR-20: Implications for Trichomoniasis

   Ramírez-Ledesma MG, Ávila EE, Alva-Murillo N · Molecules (Basel, Switzerland) · 2026PubMed Verified

9. 9.
   Fever enhances host bacterial defense while limiting mitochondrial damage

   Gross S, Wu Y, Rowe E, Siryaporn A · Research square · 2026PubMed Verified

10. 10.
    Structural determinants of glycosaminoglycan oligosaccharides as LL-37 inhibitors in breast cancer

    Le Fournis C, Maszota-Zieleniak M, Kulesza A, Chopra P, Boons GJ, Aubrey N et al. · Glycobiology · 2026PubMed Verified

11. 11.
    Lithospermic acid, a novel KLK5 inhibitor, ameliorates rosacea by suppressing the TLR4/NF-κB signaling pathway and rectifying phenylalanine metabolism

    Xu J, Wang X, Chen M, Xu B, Zhang T, Zhang Y et al. · Frontiers in immunology · 2026PubMed Verified

12. 12.
    Markov State Models Reveal How hLL-37(17-29) Tetramers Relax from a Disordered State to a Cross-α Amyloid Geometry

    Mitra A, Paul S · The journal of physical chemistry. B · 2026PubMed Verified

13. 13.
    Evaluation of the relationship between salivary levels of Streptococcus mutans, statherin, and cathelicidin LL-37 and early childhood caries

    Pamuk C, Ersin N, Emingil G, Ozdemir G, Vural C, Vural C et al. · BMC oral health · 2026PubMed Verified

14. 14.
    Limosilactobacillus fermentum LF61: A multidimensional study on safety and functionality from genomics to clinical application

    Jin M, Xu F, Liu Y, Jiang Z · Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association · 2026PubMed Verified

15. 15.
    CRISPR/Cas9-engineered Salmonella phage displaying antimicrobial peptide LL37 for enhanced antibacterial activity

    Jo SJ, Park SC, Kim SG · International journal of antimicrobial agents · 2026PubMed Verified

16. 16.
    Injectable self-healing hydrogel loaded with a self-assembling LL-37 derivative for treating infected skin wounds

    Ba Q, Yao J, Tian H, Meng Y, Kong Y, Jia Y et al. · International journal of pharmaceutics · 2026PubMed Verified

17. 17.
    A pH-Triggered antibacterial and lubricating dual-function hydrogel coating for infection-resistant urinary catheters

    Cheng M, Lin W, Yu J, Gao P, Shi F, Wang C et al. · Frontiers in bioengineering and biotechnology · 2026PubMed Verified

18. 18.
    Advances in the pathogenesis of rosacea

    Wang H, Zhou C · Frontiers in immunology · 2025ReviewPubMed Verified

19. 19.
    Regulation of virulence factors of Pseudomonas aeruginosa by Scutellaria baicalensis, Prunella vulgaris and antimicrobial peptide LL-37

    Xiao Q, Du K, Luo L, Luo Y, Wu X, Zhao C et al. · Journal of medical microbiology · 2026PubMed Verified

20. 20.
    Exploring mesenchymal stem cells as a novel therapeutic approach for HACEK endocarditis: a narrative review

    Kodori M, Farhadi N, Jafari GA, Afkhami H, Yousefi MH · Journal of cardiothoracic surgery · 2026ReviewPubMed Verified

21. 21.
    Dermofunctional Vehicle Downregulates LL-37 and MMPs and Upregulates IGFBP-3

    Polonini H, da Silva Olímpio FR, Oliveira CR · Current issues in molecular biology · 2025PubMed Verified

22. 22.
    New SufA Protease Inhibitors and Activity-based Probes: Design, Synthesis, and Antibacterial Activity Assessment

    Burchacka E, Postawa K, Pięta P · Current medicinal chemistry · 2026PubMed Verified

23. 23.
    The multifaceted role of antimicrobial peptides in neurodegeneration: Insights from Drosophila and beyond

    Behera P, Rangappa N, Chandrashekar M, Mishra A, Chinnathambi S, Mishra M · Advances in protein chemistry and structural biology · 2026ReviewPubMed Verified

24. 24.
    Antimicrobial peptides inhibit Tau aggregation and modulates its pathology

    Chinnathambi S, Rangappa N, Malik S · Advances in protein chemistry and structural biology · 2026ReviewPubMed Verified

25. 25.
    Structural insights, immunomodulatory functions, and therapeutic potential of host defense peptides in avoiding antimicrobial resistance

    Rodrigues GR, Leite ML, Franco OL · Advances in protein chemistry and structural biology · 2026ReviewPubMed Verified

26. 26.
    Increased cathelicidin LL-37 colonic expression is associated with tumor progression in colorectal cancer

    Wlodarczyk J, Dziki L, Fichna J · Journal of physiology and pharmacology : an official journal of the Polish Physiological Society · 2025PubMed Verified

27. 27.
    Epithelial Heparan Sulfate Promotes Staphylococcus aureus Corneal Infection by Inhibiting Cathelicidins

    Hayashida K, Esko JD, Gallo RD, Liu J, Kao WW, Park PW · Proteoglycan research · 2025PubMed Verified

28. 28.
    LL-37 antimicrobial peptide: Molecular characterisation and its role in oral health and disease-A narrative review

    Soman D, P J, Cm M, Radhakrishnan R · Archives of oral biology · 2026ReviewPubMed Verified

29. 29.
    Comparing the genetic and serum expression of LL-37 Antimicrobial Peptide in pemphigus vulgaris and pemphigus foliaceus patients

    Dhaffouli F, Elloumi N, Sellami K, Bahloul E, Tahri S, Turki H et al. · Anais brasileiros de dermatologia · 2026PubMed Verified

30. 30.
    Low-dose lipopolysaccharide pretreatment enhanced the proliferation and antibacterial activity of human adipose-derived mesenchymal stem cells

    Li L, Diao J, Wang F, Wang X, Liu Y, Fu X · Regenerative therapy · 2026PubMed Verified

31. 31.
    Single Amino Acid Modulates Antimicrobial Peptide Cooperativity between LL-37 and HNP1

    Schwitter AM, Yasuda T, Li X, Sugihara K · Langmuir : the ACS journal of surfaces and colloids · 2026PubMed Verified

32. 32.
    LL-37 and citrullinated-LL-37 enhances oxylipins: citrullination attenuates LL-37-mediated COX-2-dependent chemokine response in human bronchial epithelial cells

    Ramotar P, Hemshekhar M, Altieri A, M van der Does A, Pascoe CD, Mookherjee N · Respiratory research · 2026PubMed Verified

33. 33.
    α-Helical Peptides Encoded in Collagen Exhibit Antimicrobial Activity with Low Cytotoxicity

    Jarmusch SA, Muhammad T, Göransson U, Strömstedt AA · Journal of natural products · 2026PubMed Verified

34. 34.
    Clinical Safety and Tolerability of Bifidobacterium bifidum BBi32: An 8-Week Randomized, Double-Blind, Placebo-Controlled Trial With Genomic and In Vitro Corroboration

    Fang S, Wang S, Liu Y, Zhu C, Wang S, Xu F · Food science & nutrition · 2026PubMed Verified

35. 35.
    Unveiling balanced prenatal microbial colonization in amniotic fluid through an integrated culture and sequencing approach

    González-Rovira M, Sainz-Bueno JA, García-Díaz L, Martínez-Pancorbo C, Sánchez J, Gutiérrez G et al. · Journal of translational medicine · 2026PubMed Verified

36. 36.
    SARS-CoV-2 peptide fragments selectively dysregulate specific immune cell populations via Gaussian curvature targeting

    Zhang Y, Silvestre-Roig C, Fu H, Alimohamadi H, Mandal T, Chen JW et al. · Proceedings of the National Academy of Sciences of the United States of America · 2026PubMed Verified

37. 37.
    Microbiota modulation by a human Paneth cell α-defensin fragment protects against DSS-induced colitis

    Bonazzi E, Hao F, Patterson AD, Peyrin-Biroulet L, Jensen BAH, Chassaing B · iScience · 2026PubMed Verified

38. 38.
    Immunomodulatory effects of cathelicidin in the gut-brain axis: A novel link between mucosal immunity and neuroinflammation

    Nourizadeh M, Ghahari AA, Zandi E, Rasouli SZ, Davari S, Hoseinzadeh M et al. · Experimental physiology · 2026ReviewPubMed Verified

39. 39.
    LL-37-derived peptide shows promising antimicrobial potential against multidrug-resistance pathogens

    Asmamaw D, Cai H, Prateeksha P, Khalid M, Mwangi J, Yi W et al. · European journal of medicinal chemistry · 2026PubMed Verified

40. 40.
    Extended-Spectrum β-Lactamase-Producing Escherichia coli and Pediatric UTIs: A Review of the Literature and Selected Experimental Observations

    Tamas V, Ulloa ER, Kumaraswamy M, Dahesh S, Zurich R, Nizet V et al. · Antibiotics (Basel, Switzerland) · 2025ReviewPubMed Verified

41. 41.
    Differences in Inflammatory Genetic Profiles in Periodontitis Associated with Genetic and Immunological Disorders: A Systematic Review

    Astolfi-Labrador L, Cabezas-Corado Á, Torres-Lagares D, Baus-Domínguez M · Biomedicines · 2025ReviewPubMed Verified

42. 42.
    CXCL2-TLR4 axis activates NETs by accelerating autophagy through ATG7 to promote the progression of idiopathic interstitial pneumonia

    He J, Li J, Bai M, Yang J · Molecular immunology · 2026PubMed Verified

43. 43.
    LL-37 as a biomarker for therapeutic response to scaling and root planing

    Rao KS, Yadalam PK, Ravishankar PL, Rajula PB, Ravikumar H, Arunraj DR · Journal of Indian Society of Periodontology · 2025PubMed Verified

44. 44.
    The dysregulation of innate immunity by Porphyromonas gingivalis in the etiology of Alzheimer's disease

    Barron AE, Lin JS, Ryder MI, Bergman P · Journal of internal medicine · 2026ReviewPubMed Verified

45. 45.
    Pneumococcal S protein coordinates cell wall modification and repair to resist host antimicrobials

    Burnier J, Gallay C, Bruce KE, Bjånes E, Martin L, Jim KK et al. · Nature microbiology · 2026PubMed Verified

46. 46.
    Synthetic antimicrobial peptide LD4-PP protects the host against E. coli-induced cell death

    Mohanty S, White JK, Yin Y, Muhammad T, Demirel I, Strömstedt AA et al. · Frontiers in immunology · 2025PubMed Verified

47. 47.
    Dissolving microneedle co-deliver mitochondria-targeted Nanozyme and Tofacitinib for synergistic treatment of Rosacea

    Huang Y, Lu W, Hu J, Lang J, Zhu Q, Zhu J et al. · Journal of controlled release : official journal of the Controlled Release Society · 2026PubMed Verified

48. 48.
    Structural and mechanistic divergence in LL-37, HNP-1, and Magainin-2: An integrated computational and biophysical analysis

    Yakobi SH, Nwodo UU · Current research in structural biology · 2025PubMed Verified

49. 49.
    Convergence of plasmid-driven virulence and antibiotic resistance in Escherichia coli

    Lian ZJ, Nhu NTK, Ravi C, Chang C, Martinez-Roman I, Phan MD et al. · Nature communications · 2025PubMed Verified

50. 50.
    LL-37-biofunctionalized titanium improves soft tissue seal surrounding the dental implant from the perspective of optimizing a race to the surface

    Li Y, Huang J, Zhang Y, He Y, Cai D, Xu M et al. · Regenerative biomaterials · 2025PubMed Verified