LL-37
Peptide ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
LL-37 is a human cathelicidin-derived antimicrobial peptide involved in innate immune defense, inflammation, angiogenesis, and wound healing. It is not FDA-approved for general infection treatment, immune support, or systemic use; topical venous-ulcer trials remain investigational. LL-37 can be immunologically active and concentration-dependent cytotoxicity is a real concern in experimental literature.
Exploratory record, not a reviewed medical publication.
See the editorial and medical-review policies for the publication gate.
This safety record covers a controlled, investigational, or otherwise out-of-scope substance. It remains available for reference, but it is not part of NutriStack's public supplement publication set.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
LL-37 is a peptide most often used for innate antimicrobial activity in laboratory models, studied for venous leg ulcer healing, may support keratinocyte migration in research. NutriStack rates the overall evidence as emerging. A typical adult dose is No FDA-approved human dose; topical wound trials used protocol-specific concentrations, commonly taken as investigational topical wound product only; avoid systemic research use. This profile indexes 3 sources.
- Local burning or irritation
- Worsening inflammation at high concentrations
- Cytotoxicity in experimental systems
- Autoimmune or inflammatory skin disease without clinician review
- Active severe infection requiring antibiotics
The bottom line
Evidence rating emerging. Most-documented uses: innate antimicrobial activity in laboratory models, studied for venous leg ulcer healing, may support keratinocyte migration in research. 3 sources indexed (2005–2021), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
LL-37 can disrupt microbial membranes and also acts as an immune signaling peptide through epithelial, neutrophil, mast-cell, and endothelial pathways. It promotes keratinocyte migration, may transactivate EGFR, and can support angiogenesis in wound models. The same membrane and immune activity that makes it interesting also creates toxicity, inflammation, and formulation challenges.
Dosing & protocol.
Peptides are generally not reliably orally bioavailable unless a specific studied oral formulation is used. Human use of research-grade products is not appropriate.
What it actually costs.
Real-world pricing across three quality tiers. Assumes Investigational Topical LL-37 Gel.
Research-market pricing is not a dosing recommendation; human use is not FDA-approved unless specifically stated. Updated 2026-06-04.
Full safety detail.
Side effects
- Local burning or irritation
- Worsening inflammation at high concentrations
- Cytotoxicity in experimental systems
- Injection-site reaction if misused
- Allergic reaction
- Unknown autoimmune effects
Contraindications
- Autoimmune or inflammatory skin disease without clinician review
- Active severe infection requiring antibiotics
- Pregnancy and breastfeeding
- Use in eyes, bloodstream, or deep wounds outside research
- Use of research-grade injectable products
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Randomized controlled trials
2- 1Evaluation of LL-37 in healing of hard-to-heal venous leg ulcers: A multicentric prospective randomized placebo-controlled clinical trialMahlapuu M et al. · Wound Repair and Regeneration · 2021
Larger phase IIb trial tested topical LL-37
- 2Treatment with LL-37 is safe and effective in enhancing healing of hard-to-heal venous leg ulcers: a randomized, placebo-controlled clinical trialGronberg A et al. · Wound Repair and Regeneration · 2014
Topical LL-37 showed healing signals at selected concentrations
Mechanistic & preclinical
1- 3Induction of keratinocyte migration via transactivation of the epidermal growth factor receptor by the antimicrobial peptide LL-37Tokumaru S et al. · Journal of Immunology · 2005
LL-37 stimulated keratinocyte migration
Common questions.
Quick answers about LL-37, drawn from the data on this page.
What is LL-37?
LL-37 is a human cathelicidin-derived antimicrobial peptide involved in innate immune defense, inflammation, angiogenesis, and wound healing. It is not FDA-approved for general infection treatment, immune support, or systemic use; topical venous-ulcer trials remain investigational. LL-37 can be immunologically active and concentration-dependent cytotoxicity is a real concern in experimental literature.
What is LL-37 used for?
Commonly cited benefits of LL-37 include: Innate antimicrobial activity in laboratory models; Studied for venous leg ulcer healing; May support keratinocyte migration in research; No approved systemic antimicrobial use. NutriStack rates the overall evidence as emerging.
What is a typical dose of LL-37?
A typical adult dose of LL-37 is No FDA-approved human dose; topical wound trials used protocol-specific concentrations. The commonly recommended form is Investigational topical wound product only; avoid systemic research use. These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of LL-37?
Reported side effects include local burning or irritation, worsening inflammation at high concentrations, cytotoxicity in experimental systems, injection-site reaction if misused, allergic reaction, unknown autoimmune effects. This is educational information; check with a healthcare professional before use.
How strong is the evidence for LL-37?
NutriStack rates this as Emerging, meaning early RCT signal, mechanistic data, or limited human evidence. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Use this with your stack
LL-37 in NutriStack.
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