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Specimen Atlas of Research Peptides81 plates · MIT
Side-by-side · Research reference

LivagenvsLL-37

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

AAnimal-StrongHUMAN-REVIEWED20/32 cited
BHuman-MechanisticHUMAN-REVIEWED15/35 cited
Livagen
Khavinson Bioregulator · Hepatoprotective Tetrapeptide
50%Dipeptidase inhibitionTimofeeva 2005
Oral / SQRoutes tested
LiverTarget tissueKhavinson 2001
Oral or SQ · Tissue-specific to liver
LL-37
Cathelicidin · Human AMP
Broad-spectrumAntimicrobial activity
Membrane disruptionPrimary mechanismLu 2026He 2026
Innate immunityHost defense rolePinheiro 2026Zhang 2026
Endogenous · Secreted at inflammation sites

01Mechanism of Action

Parameter
Livagen
LL-37
Primary target
Hepatocyte protein synthesis machineryBrodskiĭ 2001
Bacterial membranes · Phosphatidylserine-exposed cellsHe 2026Lu 2026
Pathway
Tissue-specific bioregulator → Hepatocyte stimulation → Protein synthesis normalizationBrodskiĭ 2001Khavinson 2001
hCAP-18 precursor → Proteinase-3 cleavage → LL-37 release → Membrane insertion/disruption
Downstream effect
Age-dependent enzyme normalization, hepatoprotection in fibrosis/hepatitis models, elevated protein synthesis in senescent hepatocytes
Membrane permeabilization, cytokine induction, autophagy, phagosome-lysosome fusion, chemotaxisAhmad 2026Zhang 2026
Feedback intact?
Origin
Directed chemical synthesis from amino acid analysis of liver polypeptide preparations (Ventvil)
Endogenous human cathelicidin (37-AA fragment, residues 134–170 of hCAP-18)
Antibody development

02Dosage Protocols

Parameter
Livagen
LL-37
Animal dose (oral)
Not specified in abstracts; 2-week administration protocolTimofeeva 2005
Per os administration in rats.
Duration (experimental)
2 weeks (enzyme study); up to 24 months (cell culture)Timofeeva 2005Brodskiĭ 2001
Route
Oral or subcutaneous
Resists peptidase hydrolysis, enabling oral bioavailability.Timofeeva 2005
Evidence basis
Animal models (rats, 1–24 months age); in vitro hepatocyte cultureTimofeeva 2005Brodskiĭ 2001Khavinson 2002
In vitro, animal models, human observational
Human data
None in provided literature
Endogenous expression
Constitutive in neutrophils, epithelial tissues
Upregulated during infection and inflammation.Pinheiro 2026
Exogenous (experimental)
Dose varies by study; antimalarial ~10–50 μM in vitro
No FDA-approved exogenous formulation.
Plasma levels (malaria)
Elevated in infected patients and miceHe 2026
Exogenous administration reduced parasitemia in murine models.He 2026

04Side Effects & Safety

Parameter
Livagen
LL-37
Reported adverse effects
None documented in animal studies
Human safety data
No human trials in provided literature
Peptide hydrolysis
Weakly hydrolyzed; minimal breakdown by intestinal enzymesTimofeeva 2005
Cytotoxicity (high dose)
Membrane disruption in host cells at supraphysiological concentrations
Pro-inflammatory signaling
Can exacerbate inflammation in certain contexts (context-dependent)Pinheiro 2026
Biofilm formation risk
LL-37-DNA complexes may stabilize dental plaque biofilmsTanabe 2026
Theoretical cancer risk
Immunomodulatory roles in tumor microenvironment under investigation
Absolute Contraindications
Livagen
LL-37
Relative Contraindications
Livagen
LL-37
  • ·Active autoimmune disease (theoretical immune dysregulation)

05Administration Protocol

Parameter
Livagen
LL-37
1. Route selection
Oral administration supported by peptidase resistance. Subcutaneous route used in organotypic culture experiments.Timofeeva 2005Khavinson 2001
LL-37 is constitutively expressed in neutrophils and epithelial cells, cleaved from hCAP-18 by proteinase-3 at sites of infection or inflammation.
2. Timing
No specific timing documented. Two-week protocols used in animal models with daily administration.Timofeeva 2005
Synthetic LL-37 and derivatives (e.g., SAMP-12aa) tested in vitro and animal models. Administered via topical, intraperitoneal, or intravenous routes in research settings.
3. Age-dependent response
Elderly individuals may exhibit different enzyme normalization patterns than younger cohorts, based on rat age-stratified findings.Timofeeva 2005
LL-37 is resistant to pepsin degradation at gastric pH. Synthetic short peptides designed to retain this stability while reducing toxicity.Lu 2026