What is LL-37 (cathelicidin)?

The body's own antimicrobial peptide, described as the strongest of its class.

LL-37 (cathelicidin) in the library · · Human Trials · What are peptides?

5 registered trials · 33 indexed papers · 1015 human / 555 animal studies

From the PeptideWhiz library entry. "As described" sections summarize claims made in the sources; they are not PeptideWhiz endorsements.

What it is

The body's own antimicrobial peptide, characterized as the strongest of its class.

Mechanism (as described)

Breaks bacterial membranes and disrupts the biofilms pathogens hide in.
Supports gut microbial balance and wound repair.

Registered human trials (5)

Trial	Phase	Status	Year	Enrolled
Peri-implant Vitamin D and Cathelicidin (LL-37) Levels		completed	2021	33
Efficacy of LL-37 Cream on Bacteria Colonization, Inflammation Response and Healing Rate of Diabetic Foot Ulcers	Phase 2	unknown	2019	40
Salivary TAS, TOS, LL-37 and Dental Status in Passive Smoking Children		completed	2016	180
Intratumoral Injections of LL37 for Melanoma	Phase 1/Phase 2	completed	2015	4
Effects of Smoking and Vitamin D3 on the Levels of Human Cathelicidin Peptide LL-37		completed	2011	60

Peer-reviewed studies (33)

Paper	Authors	Journal	Year	Type
Plasma levels of antimicrobial peptide LL-37 as a biomarker of sleep quality in patients with obstructive sleep apnea: A clinical observational study	Yamaguchi T et al.	PloS one	2026	Observational Study
LL-37-ApoB-100 Complex Serves as a Biomarker of Coronary Artery Disease	Fang Y et al.	Arteriosclerosis, thrombosis, and vascular biology	2026	Observational Study
A Comparison of Cathelicidin Levels in the Skin of Leprosy Patients and Their Household Contacts	Argentina F et al.	Acta medica academica	2023	Observational Study
Efficacy and safety of Oral LL-37 against the Omicron BA.5.1.3 variant of SARS-COV-2: A randomized trial	Zhao Y et al.	Journal of medical virology	2023	Randomized Controlled Trial
Efficacy of LL-37 cream in enhancing healing of diabetic foot ulcer: a randomized double-blind controlled trial	Miranda E et al.	Archives of dermatological research	2023	Randomized Controlled Trial
The impact of vitamin D supplementation on serum cathelicidin levels and the clinical course of atopic dermatitis in children	Tsotra K et al.	Minerva pediatrics	2023	Observational Study
Evaluation of LL-37 in healing of hard-to-heal venous leg ulcers: A multicentric prospective randomized placebo-controlled clinical trial	Mahlapuu M et al.	Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society	2021	Randomized Controlled Trial
LL-37 promotes neutrophil extracellular trap formation in chronic rhinosinusitis with nasal polyps	Cao Y et al.	Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology	2019	Clinical Trial
Vitamin D was not associated with survival or cerebrospinal fluid cathelicidin levels in children with bacterial meningitis	Savonius O et al.	Acta paediatrica (Oslo, Norway : 1992)	2018	Clinical Trial
Reduction of respiratory infections in asthma patients supplemented with vitamin D is related to increased serum IL-10 and IFNγ levels and cathelicidin expression	Ramos-Martínez E et al.	Cytokine	2018	Randomized Controlled Trial
Cerebrospinal Fluid Cathelicidin Correlates With the Bacterial Load and Outcomes in Childhood Bacterial Meningitis	Savonius O et al.	The Pediatric infectious disease journal	2018	Clinical Trial
Is cathelicidin a novel marker of diabetic microangiopathy in patients with type 1 diabetes?	Uruska A et al.	Clinical biochemistry	2017	Clinical Trial
Serum level of cathelicidin LL-37 in patients with active tuberculosis and other infectious diseases	Majewski K et al.	Journal of biological regulators and homeostatic agents	2017	Randomized Controlled Trial
Circulating cathelicidin LL-37 in adult patients with pulmonary infectious diseases	Majewski K et al.	Clinical and investigative medicine. Medecine clinique et experimentale	2017	Clinical Trial
Cholecalciferol Additively Reduces Serum Parathyroid Hormone and Increases Vitamin D and Cathelicidin Levels in Paricalcitol-Treated Secondary Hyperparathyroid Hemodialysis Patients	Zheng JQ et al.	Nutrients	2016	Randomized Controlled Trial
A randomized controlled trial on the effect of vitamin D3 on inflammation and cathelicidin gene expression in ulcerative colitis patients	Sharifi A et al.	Saudi journal of gastroenterology : official journal of the Saudi Gastroenterology Association	2016	Randomized Controlled Trial
Effect of Cholecalciferol Supplementation on Vitamin D Status and Cathelicidin Levels in Sepsis: A Randomized, Placebo-Controlled Trial	Quraishi SA et al.	Critical care medicine	2015	Randomized Controlled Trial
Increased serum levels of LL37, HMGB1 and S100A9 during exacerbation in COPD patients	Pouwels SD et al.	The European respiratory journal	2015	Randomized Controlled Trial
Human cathelicidin antimicrobial protein 18 (hCAP18/LL-37) is increased in foetal membranes and myometrium after spontaneous labour and delivery	Lim R et al.	Journal of reproductive immunology	2015	Clinical Trial
Diagnostic value of anti-microbial peptide, cathelicidin in congenital pneumonia	Gad GI et al.	The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians	2015	Clinical Trial
Favorable interleukin-8 induction in human gingival epithelial cells by the antimicrobial peptide LL-37	Montreekachon P et al.	Asian Pacific journal of allergy and immunology	2014	Clinical Trial
Prenatal vitamin D₃ supplementation suppresses LL-37 peptide expression in ex vivo activated neonatal macrophages but not their killing capacity	Raqib R et al.	The British journal of nutrition	2014	Randomized Controlled Trial
Treatment with LL-37 is safe and effective in enhancing healing of hard-to-heal venous leg ulcers: a randomized, placebo-controlled clinical trial	Grönberg A et al.	Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society	2014	Randomized Controlled Trial
Citrullination alters immunomodulatory function of LL-37 essential for prevention of endotoxin-induced sepsis	Koziel J et al.	Journal of immunology (Baltimore, Md. : 1950)	2014	Clinical Trial
A cross sectional analysis of the role of the antimicrobial peptide cathelicidin in lung function impairment within the ALIVE cohort	Lambert AA et al.	PloS one	2014	Observational Study
Effect of vitamin D supplementation on cathelicidin, IFN-γ, IL-4 and Th1/Th2 transcription factors in young healthy females	Das M et al.	European journal of clinical nutrition	2014	Randomized Controlled Trial
Oral intake of phenylbutyrate with or without vitamin D3 upregulates the cathelicidin LL-37 in human macrophages: a dose finding study for treatment of tuberculosis	Mily A et al.	BMC pulmonary medicine	2013	Clinical Trial
The role of the Src family kinase Lyn in the immunomodulatory activities of cathelicidin peptide LL-37 on monocytic cells	Nijnik A et al.	Journal of leukocyte biology	2012	Clinical Trial
Vitamin D status and antimicrobial peptide cathelicidin (LL-37) concentrations in patients with active pulmonary tuberculosis	Yamshchikov AV et al.	The American journal of clinical nutrition	2010	Randomized Controlled Trial
Topical treatment with the vitamin D analogue calcipotriol enhances the upregulation of the antimicrobial protein hCAP18/LL-37 during wounding in human skin in vivo	Heilborn JD et al.	Experimental dermatology	2010	Controlled Clinical Trial

More cited research

Coordination chemistry and antimicrobial activity of LL-37, its C-terminal fragment, and a peptidomimetic analogue (2026, human observational)
Elevated Serum LL37 and Myeloperoxidase-DNA Complexes Predict the Progression of Diabetic Kidney Disease (2026, human observational)
Evaluation of the relationship between salivary levels of Streptococcus mutans, statherin, and cathelicidin LL-37 and early childhood caries (2026, human observational)
Exposure to the antimicrobial peptides LL-37 and ATRA-1 induces a lipidome response in Staphylococcus aureus that alters membrane biophysical properties (2026, human observational)
A degradable hydrogel scaffold incorporating the LL-37 for gingival soft tissue regeneration (2026, animal)
Antimicrobial peptide LL37 ameliorated experimental inflammation induced neonatal lung injury through macrophage immunomodulation (2026, animal)
Calmodulin-tagging prevents aggregation and facilitates the proteolytic release of the recombinant human cathelicidin LL-37 by accommodating its hydrophobic reg (2026, animal)
Cathelicidin LL-37 inhibits angiogenesis and migration in gastric cancer via inhibition of NF-κB/IL-6 signaling (2026, animal)

Conditions researched

Related compounds

FAQ

What is LL-37 (cathelicidin)?

The body's own antimicrobial peptide, described as the strongest of its class.

How many registered human trials study LL-37 (cathelicidin)?

The PeptideWhiz trial index lists 5 registered trials for LL-37 (cathelicidin), the most recent from 2021.

How much published research exists on LL-37 (cathelicidin)?

The PeptideWhiz paper index links 33 PubMed papers to LL-37 (cathelicidin); by study type, 1015 human and 555 animal studies.

Which conditions is LL-37 (cathelicidin) researched for?

Lyme disease & chronic infections, Mold illness (mycotoxin exposure), Gut: IBD (Crohn's, colitis), leaky gut, IBS & ulcers, Recurrent vaginal infections & vaginal atrophy, Candida & persistent bacterial infections, Gum disease (periodontal) & oral health, Lupus (SLE), Skin, hair loss, wounds & mast-cell/histamine reactivity, EBV and reactivated viruses, Psoriasis and psoriatic arthritis, Acne, Recurring UTIs, Hyperparathyroidism, Lipedema, Atherosclerosis, cardiovascular disease & high blood pressure, Chronic and systemic inflammation, Eczema, Immune system (general), Insulin resistance, prediabetes & type 2 diabetes, Lung health, asthma & COPD, Sleep apnea (obstructive), Sleep problems (incl. insomnia on peptides).

Research and education only. Not medical advice. No dosing guidance. Data: ClinicalTrials.gov registry and PubMed via the PeptideWhiz index (204,289 studies).

Reported dosing ranges from research