What Is LL-37?
LL-37, also known as human cathelicidin antimicrobial peptide, is a 37-amino acid cationic peptide that serves as a critical component of the innate immune system. It is one of the most researched antimicrobial peptides due to its broad-spectrum activity against bacteria, viruses, fungi, and biofilms, along with its powerful immunomodulatory and tissue repair properties.
LL-37 is frequently studied in contexts involving infection resistance, chronic wound healing, inflammatory conditions, and immune system modulation.
How LL-37 Works
LL-37 disrupts microbial membranes through pore formation and oligomerization, leading to cell lysis. Beyond direct antimicrobial action, it modulates immune responses by influencing cytokine production, promoting angiogenesis, stimulating cell migration, and regulating inflammation. It can shift macrophages toward a pro-healing phenotype and enhance wound closure while preventing excessive inflammatory damage.
Key Research-Backed Benefits of LL-37
Broad-Spectrum Antimicrobial Activity
Effective against gram-positive and gram-negative bacteria, enveloped viruses, fungi, and antibiotic-resistant strains.
Anti-Biofilm Effects
Inhibits biofilm formation and disrupts existing biofilms at concentrations much lower than those needed to kill free-floating bacteria.
Accelerated Wound Healing
Promotes re-epithelialization, collagen synthesis, angiogenesis, and tissue regeneration in chronic wound models.
Immune System Modulation
Balances pro- and anti-inflammatory responses, supporting immune resilience without overactivation.
Anti-Inflammatory Properties
Helps resolve excessive inflammation while supporting repair processes.
Potential in Skin and Gut Health
Studied for its role in skin barrier function and gastrointestinal protection.
LL-37 Research Dosage Protocols
Important: The following information is compiled from published preclinical and clinical research for laboratory and in vitro use only. Always follow institutional safety guidelines.
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General Immune Support / Systemic Research: 50–100 mcg/kg subcutaneously once daily or every other day for 2–4 weeks (common exploratory range).
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Wound Healing Research (Topical or Local): 50–100 mcg per application near the wound site, daily or every other day until healing progress is observed. Clinical trials have used topical concentrations of 0.5 mg/mL and 1.6 mg/mL applied twice weekly with notable healing improvements.
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Antimicrobial / Infection Models: 100–300 mcg subcutaneously once daily (typical reconstitution: 5 mg vial with 3 mL bacteriostatic water yields ~1.67 mg/mL).
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Loading vs Maintenance: Many protocols begin with 100–200 mcg daily for 5–7 days, then reduce to maintenance dosing 2–3 times per week.
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Cycle Length: Research cycles commonly run 2–4 weeks on, followed by equal time off.
Reconstitution Note (Research Use Only): Reconstitute with bacteriostatic water. Use precise micro-dosing syringes and calculate concentrations accurately.
Why Researchers Study LL-37
LL-37 stands out for combining direct pathogen-fighting ability with tissue repair and immune-balancing effects. It is especially valuable in research on antibiotic-resistant infections, chronic wounds, and age-related immune decline.
Research-Grade LL-37
Important Research Notice: LL-37 is sold by Amino Fuel Labs strictly for laboratory research and in vitro use only. It is not FDA-approved for human consumption.
For research professionals studying immunology, antimicrobial peptides, wound healing, or inflammation, we provide high-purity LL-37 with independent testing and fast domestic shipping.
Explore More Research Peptides
Browse our full research peptide catalog including Melanotan II, Thymosin Alpha-1, BPC-157, TB-500, GHK-Cu, Retatrutide, Tirzepatide, and AOD9604.
Have questions about LL-37 research protocols, reconstitution, or potential synergies with other peptides? Leave a comment below — we're here to support the research community.
This article is for educational and research purposes only. LL-37 is sold for research use only and is not intended for human consumption.
