Immune
LL-37
Also known as Cathelicidin
Human antimicrobial peptide studied in lab and early clinical settings.
Where the evidence comes from
21 verified records from 13 countries. The number of studies or countries is not proof that LL-37 works or is safe.
Narrative review: 10 · Observational human study: 4 · Animal study: 1 · Randomized clinical trial: 3 · Human clinical trial: 3
What is known
Editorial summary not yet written.
What remains uncertain
Editorial summary not yet written.
Conflicting findings
Editorial summary not yet written.
U.S. regulatory status (FDA)
Compound
Product or formulation
FDA status
FDA-approved branded drug
Approved indication
Metara availability (compounded formulation)
Research material (research use only)
Source
Last verified
Notes
Approval applies only to the exact finished drug, formulation and indication. A shared active ingredient does not make a compounded version, blend or other use FDA-approved. Pharmacy or research-material availability is not FDA approval.
International regulatory status
Kept separate from U.S. status. The regulator's country is not the same as where studies took place.
No sourced international decisions recorded yet.
Continue your research
These are two different pathways, not two ways to get the same thing. Neither changes the FDA status shown above.
Clinical care
Available through Metara Health
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EXPLORE METARA HEALTH →Limitations
Mostly lab data; small early-phase human studies for wound healing.
Human clinical evidence (10)
"Salivary Levels of Cathelicidin LL-37 in Patients With Oral Potentially Malignant Lesions, A Case Control Study"
Fayoum University · ClinicalTrials.gov · NCT06219330
This completed human case-control study examined salivary LL-37 in patients with potentially malignant oral lesions and healthy controls. The abstract reports strong diagnostic accuracy in distinguishing these groups and suggests LL-37 could serve as a noninvasive marker for early detection.
The Role of Anti-inflammatory Cytokines and Antimicrobial Peptide LL-37 Biomarkers in the Treatment of Periodontal Disease.
Universidad Rey Juan Carlos · ClinicalTrials.gov · NCT04404335
This registered human observational study examined LL-37 and immune-related proteins in fluid between the gums and teeth in people with and without gum disease, including changes after periodontal treatment. The study is marked completed, but the record provides no results.
Evaluation of Peri-Implant Sulcus Fluid Vitamin D and Cathelicidin (LL-37) Levels in Peri-Implant Health and Diseases
Altinbas University · ClinicalTrials.gov · NCT06867250
This completed human observational study examined vitamin D and LL-37 in fluid around dental implants, focusing on immune defenses and inflammation in healthy and diseased surrounding tissues. The abstract describes the study aims but reports no results.
Cathelicidin LL-37 Levels in the Gingival Crevicular Fluid and the Saliva of Smokers and Non-smokers With Stage III,IV Periodontitis :An Observational Study
Cairo University · ClinicalTrials.gov · NCT04861493
This completed human observational study examined LL-37 levels in saliva and fluid around the gums in smokers and non-smokers with advanced periodontitis. The supplied abstract provides background on gum disease and smoking but reports no study results.
The Efficacy of LL-37 Cream on Aerobic Bacteria Colonization Pattern, Inflammation Response: Interleukin 1α (IL-1α) and Tumor Necrosis Factor α (TNF-α), and Healing Rate of Diabetic Foot Ulcers
Fakultas Kedokteran Universitas Indonesia · ClinicalTrials.gov · NCT04098562
This registered randomized human trial planned to compare LL-37 cream with placebo alongside standard wound care for diabetic foot ulcers. It aimed to assess wound healing, bacteria, and inflammatory markers. The study status is unknown, and the abstract reports no results.
Effect of High-Dose Vitamin D3 on Alveolar Macrophage Function, LL-37, and Oxidative Stress in Smokers and Non-Smokers With and Without HIV
Emory University · ClinicalTrials.gov · NCT03270709
This registered human trial planned to examine vitamin D supplementation, lung immune-cell function, LL-37, and oxidative stress in smokers and non-smokers with and without HIV. Its goal was to investigate immune defenses against infection. The trial is listed as terminated, and the supplied abstract reports no trial results.
A Single Site Evaluation of the Inhibitory Effects of Topical Ivermectin on Serine Protease Activity and Production of LL-37 Cathelicidin Peptide, Biochemical Markers of Rosacea-specific Inflammation and on the Skin Microbiome in Rosacea.
University of California, San Diego · ClinicalTrials.gov · NCT02806414
This registered human trial examined topical ivermectin in people with rosacea, focusing on enzyme activity, the antimicrobial peptide LL-37, and microorganisms living on the skin. Researchers planned to assess whether changes in these measures correlated with disease severity. The trial is listed as completed, but the supplied abstract reports no results.
Induction of Antitumor Response in Melanoma Patients Using the Antimicrobial Peptide LL37
M.D. Anderson Cancer Center · ClinicalTrials.gov · NCT02225366
This registered clinical trial in people with melanoma aimed to investigate LL-37 and whether it could stimulate the immune system to help control the disease. The trial is listed as completed, but the supplied abstract reports no results.
Systematic & narrative reviews (10)
Antimicrobial Peptides of the Cathelicidin Family: Focus on LL-37 and Its Modifications.
Voronko OE, Khotina VA, Kashirskikh DA, Lee AA, Gasanov VAO · International journal of molecular sciences · DOI 10.3390/ijms26168103
This review examines modifications to the human antimicrobial peptide LL-37, rather than reporting a new human trial. It describes modified forms that preserve or improve biological activity while reducing toxicity and resisting breakdown by enzymes. Their therapeutic potential remains promising, but long-term safety and effectiveness require further validation.
Cathelicidin LL-37 in periodontitis: current research advances and future prospects - A review.
He Y, Zhou Y, Liu N, Zhang W, Chen X, Qiu G, Shen Y · International immunopharmacology · DOI 10.1016/j.intimp.2025.114277
This review examined LL-37 in human periodontitis, a disease affecting the tissues supporting teeth. Studies reported higher LL-37 levels in fluid around the gums of patients with periodontitis than in healthy people. The review describes antimicrobial, immune-regulating, and tissue-repair effects, while identifying potential treatments and disease markers as areas for future research.
Between good and evil: Complexation of the human cathelicidin LL-37 with nucleic acids.
Zielke C, Nielsen JE, Lin JS, Barron AE · Biophysical journal · DOI 10.1016/j.bpj.2023.10.035
This review examines research on the human immune peptide LL-37 binding to nucleic acids and affecting innate immunity; the abstract does not specify the study populations or experimental models. These complexes have shown beneficial immune-stimulating effects, but some studies suggest they may also contribute to autoimmune disorders such as psoriasis and lupus.
Antifungal properties of cathelicidin LL-37: current knowledge and future research directions.
Memariani M, Memariani H · World journal of microbiology & biotechnology · DOI 10.1007/s11274-023-03852-5
This review summarizes research on LL-37 against fungi relevant to human disease and agriculture, rather than reporting a human treatment trial. LL-37 can inhibit fungal growth through mechanisms including damage to cell walls and membranes and disruption of internal cell processes. Evidence also suggests it may reduce fungi's ability to cause disease.
Antibiofilm properties of cathelicidin LL-37: an in-depth review.
Memariani H, Memariani M · World journal of microbiology & biotechnology · DOI 10.1007/s11274-023-03545-z
This review examines research on LL-37 against bacterial biofilms, communities of bacteria embedded in a protective layer. Evidence suggests LL-37 can prevent biofilm establishment through effects on bacterial attachment, signaling, and the protective layer. Its effectiveness and safety in living organisms remain uncertain.
Cathelicidin LL-37 in Health and Diseases of the Oral Cavity.
Tokajuk J, Deptuła P, Piktel E, Daniluk T, Chmielewska S, Wollny T, Wolak P, Fiedoruk K, Bucki R · Biomedicines · DOI 10.3390/biomedicines10051086
This review examined the human peptide LL-37 in oral health and disease. It described antimicrobial and immune-regulating roles that help maintain oral microbial balance, alongside involvement in microbial imbalance, infections, autoimmune diseases, and oral cancers. LL-37 has also been proposed as a marker of inflammation severity and treatment outcomes.
Significance of LL-37 on Immunomodulation and Disease Outcome.
Yang B, Good D, Mosaiab T, Liu W, Ni G, Kaur J, Liu X, Jessop C, Yang L, Fadhil R, Yi Z, Wei MQ · BioMed research international · DOI 10.1155/2020/8349712
This review examines research on the human immune peptide LL-37 in different tissues and local environments. It describes contrasting roles: LL-37 can promote inflammation and anti-infection or antitumor responses, but can also inhibit inflammation and promote cancer development. Its effects depend on the tissue and surrounding conditions.
Roles and Mechanisms of Human Cathelicidin LL-37 in Cancer.
Chen X, Zou X, Qi G, Tang Y, Guo Y, Si J, Liang L · Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology · DOI 10.1159/000490183
This review examines LL-37's roles in human cancers, including laboratory research on cancer cells. It reports cancer-promoting effects in some cancer types and anticancer effects in others. Differences in cell-surface receptors and signaling pathways appear to help explain these tissue-specific effects.
Laboratory, animal & other research (1)
Antimicrobial peptide cathelicidin LL-37 preserves intestinal barrier and organ function in rats with heat stroke.
Shih CC, Liao WC, Ke HY, Kuo CW, Tsao CM, Tsai WC, Chiu YL, Huang HC, Wu CC · Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie · DOI 10.1016/j.biopha.2023.114565
This animal and lab study tested LL-37 in rats with heat stroke and cultured intestinal cells. LL-37 reduced intestinal injury and systemic inflammation, improved organ function, and increased survival in the rats. The researchers linked these effects to protection of mucus-producing intestinal cells and improved intestinal barrier function.
Browse worldwide evidence → · Search and filter all LL-37 studies →
Next steps
Profile last reviewed September 26, 2026. Educational content only. Not medical advice, a dosing protocol or a treatment recommendation.