peptide wiki

LL-37

aka Cathelicidin

Immune Modulator

Mechanism

LL-37 is the only human cathelicidin antimicrobial peptide — a 37-amino-acid peptide (starting with two leucines) cleaved from the hCAP-18 precursor. It has broad-spectrum antimicrobial activity and immunomodulatory roles, but is also implicated in the pathogenesis of autoimmune and inflammatory skin diseases including psoriasis, rosacea, and lupus. Not FDA-approved; research-use only.

Identification

CAS number154947-66-7
Molecular formulaC205H340N60O53
SequenceLLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES
Typical dose100–400 mcg/day subcutaneous
Half-life~4–6 hours (tissue-dependent; limited formal PK data for native LL-37)

Vendors selling LL-37

VendorSizePriceListed purityTrust
BioLongevity Labs 5 mg $94.97 96
Orbitrex Peptides 5 mg $49.99 95
Ion Peptide 5 mg $45.00 95
Peptide Tech 10 mg $49.99 94
Mile High Compounds $39.99 94
Skye Peptides 5 mg $74.00 90
Peptidology 5 mg $45.00 89
Qihang Peptide 87
Verified Peptides 5 mg $65.70 86
EZ Peptides 10 mg $78.00 85
Simple Peptide 5 mg $45.00 85
Simple Peptide 10 mg $45.00 85
Peptidegurus 5 mg 84
Ascension Peptides 10 mg $89.00 84
Reta Peptide 83
MedGe Peptides 5 mg $75.00 82
Texpeptide 5 mg $40.00 70
Qing Li Peptide 63
Certified Peptides 5 mg $89.00 62
Peptiatlas 51
DongCheng Peptide 46
Mandy 5 mg $74.00 43
HongDa Peptide $109.00 43
zztai Peptide Ltd 43
MJT peptides 5 mg $100.00 39
AMC Essentials 5 mg $127.99
AMC Essentials 5 mg $42.99
Alpha Omega 5 mg $45.00
Alpha Omega 10 mg $45.00
Atomik Labz 5 mg $77.00
Biotech Peptides 5 mg $86.00
Core Peptides 5 mg $89.00
Flawless Compounds
Genetic Peptide 5 mg $100.00
Genetic Peptide 10 mg $100.00
Kimera Chems $46.99
Modern Research Peptides 5 mg $37.99
Oasis Labs 10 mg $65.00
Paramount Peptides 10 mg $100.00
Paramount Peptides 5 mg $125.00
Paramount Peptides 5 mg $75.00
Peptide Crafters 5 mg $50.00
Peptira $39.00
Platinum Lion 10 mg $39.99
Platinum Lion 5 mg $39.99
Polaris Peptides 10 mg $125.00
Solution Peptides 5 mg $77.00
Soma Peptides 5 mg $83.00
Southern Aminos 5 mg $59.25
True Peptide 5 mg $40.00

Research

LL-37: Biological Mechanisms and Emerging Therapeutic Applications in Intestinal Disease
Liu Q, Xu P, Zhang C. · Immunity, inflammation and disease (2026) · review

Human cathelicidin peptide LL-37 is encoded by the CAMP gene and plays a key role in innate immunity. It maintains intestinal homeostasis through antibacterial, immunomodulation, and tissue repair functions.

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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 (2026) ·

BACKGROUND: During airway inflammation, chemokines, oxylipins (bioactive lipids) and cationic host defence peptides (CHDP) are enhanced in the lungs. However, the interplay of these molecules in the process of airway inflammation is not fully resolved.

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β-Amyloid (Aβ) and Human Cathelicidin LL-37: Two Sides of the Same Coin?
· International journal of molecular sciences (2026) · review
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A degradable hydrogel scaffold incorporating the LL-37 for gingival soft tissue regeneration
Mao J, Li X, Liao K, Liu L, Zheng H, Cui Y, Guo Z, Song K, Zhao J, Wu L, Zhang W, Chen J, Li W. · Regenerative biomaterials (2026) ·

Gingival recession exposes the roots, leads to dentin hypersensitivity, and heightens the progression of periodontitis, and poses a threat to oral health and appearance. Conventional treatment uses autogenous palatal grafts, requiring a second surgical site and adding patient discomfort.

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β-Amyloid (Aβ) and Human Cathelicidin LL-37: Two Sides of the Same Coin?
Asti AL. · International journal of molecular sciences (2026) · review

Physiologically produced circulating β-amyloid (Aβ) exerts critical physiological functions. Although Aβ is a key player in Alzheimer's disease (AD), it may initially be beneficial at the onset of infection.

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[Evaluation of Serum LL-37 Levels in Patients with Brucellosis and Their Relationship with Clinical Course]
Gögebakan K, Özkurt Z, Öztürk N. · Mikrobiyoloji bulteni (2026) ·

This study aimed to determine the serum levels of the LL-37 molecule, associated with the pathophysiology of Brucellosis, in patients diagnosed with Brucellosis and to investigate the relationship between these levels and the clinical course of the disease.

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Combined nonoxynol-9 and antimicrobial peptide LL-37 for barrier contraception
Xu M, Chan CPS, Cong L, Chung JPW, Fok EKL, Chan DYL. · Reproduction & fertility (2026) · animal

Abstract Birth control and sexually transmitted infections are global concerns. Nonoxynol-9 (N-9) is the most commonly used component in spermicides, with controversial safety and efficacy. LL-37 has been considered the most promising antimicrobial peptide for developing spermicides.

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Cancer cell migration under control of human cathelicidin LL-37
Żochowski K, Sadowska M, Piktel E, Pogoda K, Bucki R. · Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie (2026) · review

Cancer cell migration is a key step in the metastatic cascade. Understanding its mechanisms represents one of the greatest challenges in modern oncology. Both in vitro and in vivo experimental models and mathematical descriptions of movement dynamics are used to study this complex phenomenon.

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Effects of Botulinum Toxin A on Rosacea-Like Inflammation in an LL-37-Induced Rosacea Mouse Model
Yoon D, Lee JO, Jang YN, Yoo KH, Kim BJ, Choi SY. · Annals of dermatology (2026) · animal

Background Rosacea is a chronic inflammatory disorder characterized by flushing, erythema, papules/pustules, and telangiectasia. Several clinical studies have investigated the efficacy of botulinum neurotoxin A (BoNT/A) in the treatment of rosacea, but its mechanism of action remains unclear.

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LL-37-ApoB-100 Complex Serves as a Biomarker of Coronary Artery Disease
Fang Y, Zhang Z, Cao Q, Li Y, Duan Y, Meng P, Duan Z, Wang G, Gao J, Hua M, Huang B, Zhou T, Zhang H, Kong F, Zhang Y, Li M, Ma ZS, Li Y, Wang Z, Cheng R, Lu Q, Ni H, Lai R. · Arteriosclerosis, thrombosis, and vascular biology (2026) · cohort

Background ApoB (apolipoprotein B)-containing lipoproteins are causal risk factors for atherosclerotic coronary artery disease (CAD).

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Exploring the role of cathelicidin LL-37 and ceragenins in wound healing processes
Łuckiewicz M, Wnorowska U, Zakrzewska M, Błażejczyk I, Daniluk T, Kondziołka W, Savage PB, Bucki R, Piktel E. · European journal of pharmacology (2026) · review

Wound healing and tissue regeneration are essential for maintaining skin integrity in the face of mechanical, chemical, or thermal damage. In adult mammals, the wound healing process may include complications leading to chronic wounds and hypertrophic scars.

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Aggregation-State Dynamics Drive Double Cooperativity Between Antimicrobial Peptides LL-37 and HNP1
Hou Y, Zhang J, Takeuchi K, Higuchi H, Kaya M, Li R, Zheng J, Chen J, Watanabe G, Sugihara K. · Angewandte Chemie (International ed. in English) (2026) ·

The double cooperative effect between two major antimicrobial peptides, LL-37 and HNP1, where their combination enhances antimicrobial efficiency while reducing cytotoxicity, offers a promising strategy for developing safer and more effective antibiotics against antimicrobial resistance.

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Outcome of High Dose Vitamin D on Prognosis of Sepsis Requiring Mechanical Ventilation
· ClinicalTrials.gov (2022) · rct

There is a high prevalence of vitamin D deficiency in the critically ill patient population, with approximately 60% of patients found to be vitamin D deficient, (25(OH)D concentrations \<20 ng/mL) and an additional 30% of patients being vitamin D insufficient, (25(OH)D = 20-30 ng/mL).Approximately 80% of sepsis/septic…

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Cathelicidin LL-37 Levels in the GCF and the Saliva of Smokers and Non-smokers With Stage III,IV Periodontitis
· ClinicalTrials.gov (2021) · cohort

Periodontitis is considered an inflammatory disease that results in the disruption of oral hemeostasis and is associated with the presence of dental plaque influenced by genetic and environmental factors.

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Peri-implant Vitamin D and Cathelicidin (LL-37) Levels
· ClinicalTrials.gov (2021) · cohort

This research aims to explore the influence of vitamin D on the body's defense system by examining its impact on specific proteins involved in immune response and inflammation in the soft tissues surrounding dental implants.

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Etiology of Eczema Herpeticum (EH)
· ClinicalTrials.gov (2017) · cohort

Atopic dermatitis, also called eczema, is a disease with dry, scaly, itchy skin. Those with atopic dermatitis may have complications from skin infections such as eczema herpeticum after herpes simplex virus (HSV) infection.

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Effects of Antarctic Environment on Vitamin D Status and Health Risk Biomarkers of Its Inhabitants
· ClinicalTrials.gov (2016) · rct

The purpose of this study is to evaluate vitamin D (VD) deficiency in the population of Chilean Antarctica and evaluate the efficacy and safety of VD supplementation to decrease VD deficiency and favorably influence biomarkers for bone, cardiovascular, and immune health risk in the inhabitants of Chilean Antarctica.

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A Study to Evaluate the Safety, Tolerability, Pharmacokinetics (PK), Pharmacodynamics (PD) and Food Effect of Single or Repeat Doses of GSK2793660 in Healthy Subjects
· ClinicalTrials.gov (2014) · rct

This study is the first administration of GSK2793660 to humans and will evaluate the safety, tolerability, PK and PD of single oral ascending doses of GSK2793660, and of repeat oral doses of GSK2793660 in healthy subjects. The study will comprise two parts (Part A and Part B).

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Cholecalciferol Supplementation for Sepsis in the ICU
· ClinicalTrials.gov (2014) · rct

Sepsis in a clinical entity that occurs in patients with serious infections. Though the severity of illness may vary, every year, approximately 1.6 million Americans are treated for sepsis. Even with timely interventions, anywhere from 16% to \>80% of patients with sepsis will not survive.

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Comparison of Cathelicidin Expression in Skin and Saliva in Patients With Atopic Dermatitis and Psoriasis
· ClinicalTrials.gov (2005) · cohort

Cathelicidins are small proteins in the human body that protect against infection. The purpose of this study is to determine if the amount of cathelicidins and other small proteins found in saliva can predict the amount of these in the skin of people who have acute atopic dermatitis (AD) or psoriasis.

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