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
Peptide Plugs 5 mg $60.00 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 83
MedGe Peptides 5 mg $125.00 82
Texpeptide 5 mg $40.00 69
Qing Li Peptide 63
Certified Peptides 5 mg $89.00 61
Peptiatlas 51
DongCheng Peptide 46
Mandy 5 mg $74.00 43
HongDa Peptide $109.00 43
MJT peptides 5 mg $100.00 39
Kimera Chems $46.99
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
Modern Research Peptides 5 mg $37.99
Oasis Labs 10 mg $65.00
Paramount Peptides 10 mg $85.00
Paramount Peptides 5 mg $106.25
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 $42.00
True Peptide 5 mg $40.00
realpeptides.co $80.00

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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Research on the Improvement of Intestinal and Immune Functions by Probiotics
· ClinicalTrials.gov (2025) · rct

Evaluate the effectiveness and safety of Limosilactobacillus fermentum LF61 as a food supplement compared to a placebo in improving intestinal and immune functions in healthy adults.

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Relationship Between Nutritional Status, Physical Activity and Periodontal Status
· ClinicalTrials.gov (2021) · cohort

This observational retrospective study aims to evaluate the relationship between nutritional status, physical activity levels, and periodontal health in adult patients.

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Effect of High-Dose Vitamin D3 in Smokers and Non-Smokers With and Without HIV
· ClinicalTrials.gov (2018) · rct

Supplementation with vitamin D improves HIV+ macrophages phagocytosis in vitro. There is evidence to suggest that administering vitamin D can in fact improve immune function in individuals. The study will evaluate the impact of high dose vitamin D in HIV+ smokers' and HIV- smokers' in vivo.

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Efficacy Study of Vitamin D Supplementation to Meticillin Resistant Staphylococcus Aureus (MRSA) Carriers
· ClinicalTrials.gov (2014) · rct

The purpose of this study is to treat persistent MRSA carriers with vitamin D supplementation during a 12 month to see if the number of MRSA positive patients can be reduced.

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A Phase 2 Exploratory Pharmacodynamic Study of HP802-247 in Venous Leg Ulcers
· ClinicalTrials.gov (2014) · rct

Assess the influence of HP802-247 on biochemical and cellular markers of inflammation in chronic venous leg ulcers

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Effects of Aminocaproic Acid (ACA) on Rosacea-specific Inflammation
· ClinicalTrials.gov (2011) · rct

The purpose of this study is to determine the effect of topical aminocaproic acid on the immune system by assessing the levels of antimicrobial peptides in the skin of patients with rosacea.

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Effects of Smoking and Vitamin D3 on the Levels of Human Cathelicidin Peptide LL-37
· ClinicalTrials.gov (2011) · cohort

The aims of our study were 1) to evaluate levels of gingival crevicular fluid( GCF) human cathelicidin peptide LL-37 and serum vitamin D3 in smoker and non-smoker patients with chronic periodontitis(CP) 2) to determine whether any correlation between GCF LL-37 and vitamin D3 serum levels exist and 3) to asses the corre…

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Effects of Vitamin D Supplementation on Lung Function in an Acute Pulmonary Exacerbation of Cystic Fibrosis
· ClinicalTrials.gov (2008) · rct

Vitamin D insufficiency is common in patients with cystic fibrosis.

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