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

CortagenvsLL-37

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

AAnimal-MechanisticHUMAN-REVIEWED11/35 cited
BHuman-MechanisticHUMAN-REVIEWED15/35 cited
Cortagen
Bioregulatory Tetrapeptide · Khavinson-School
TetrapeptideStructure
↓ LPO productsAntioxidant effectKozina 2007
AnimalEvidence level
Injectable · Animal models
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
Cortagen
LL-37
Primary target
Cerebral cortex tissue — molecular targets under investigation
Bacterial membranes · Phosphatidylserine-exposed cellsHe 2026Lu 2026
Pathway
Antioxidant pathway modulation — suppression of LPO cascade, reduction of protein oxidative modificationKozina 2007
hCAP-18 precursor → Proteinase-3 cleavage → LL-37 release → Membrane insertion/disruption
Downstream effect
Decreased lipid peroxidation products, reduced oxidative protein damage, altered gene expression in cardiac tissueKozina 2007Anisimov 2004
Membrane permeabilization, cytokine induction, autophagy, phagosome-lysosome fusion, chemotaxisAhmad 2026Zhang 2026
Feedback intact?
Origin
Synthetic tetrapeptide derived from amino acid analysis of natural brain cortex peptide preparation CortexinAnisimov 2004
Endogenous human cathelicidin (37-AA fragment, residues 134–170 of hCAP-18)
Antibody development

02Dosage Protocols

Parameter
Cortagen
LL-37
Animal model dose (rat)
Injection protocol (dose not specified in abstracts)
Multiple injections over study period.
Avian model dose (chicken)
40-day injection courseKuznik 2008
Compared to epithalon in hypophysectomized and aged birds.
Human peripheral nerve study
Therapeutic course (protocol details not provided)
Posttraumatic recovery context — reference cited but not detailed.
Evidence basis
Animal mechanistic studies
In vitro, animal models, human observational
Route
Injectable (inferred from animal protocols)
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
Cortagen
LL-37
Antioxidant suppression
Suppression of antioxidant activity noted alongside LPO reductionKozina 2007
Mechanism unclear — possible homeostatic adaptation.
Immune/hemostasis effects
No effect on immunity or hemostasis parameters in avian hypophysectomy model (unlike epithalon)Kuznik 2008
Epithalon reversed deficits; cortagen did not.
Human safety data
No adverse events reported in peripheral nerve recovery context
Limited detail in available abstracts.
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
Cortagen
LL-37
Relative Contraindications
Cortagen
LL-37
  • ·Active autoimmune disease (theoretical immune dysregulation)

05Administration Protocol

Parameter
Cortagen
LL-37
1. Preparation
Reconstitute lyophilised peptide with bacteriostatic water per supplier protocol. Exact volumes depend on concentration supplied.
LL-37 is constitutively expressed in neutrophils and epithelial cells, cleaved from hCAP-18 by proteinase-3 at sites of infection or inflammation.
2. Injection site
Subcutaneous injection typical for bioregulatory peptides — abdomen or thigh. Rotate sites.
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. Timing
Animal protocols used repeated dosing over weeks. Human timing not established — evening administration common in Khavinson tradition.
LL-37 is resistant to pepsin degradation at gastric pH. Synthetic short peptides designed to retain this stability while reducing toxicity.Lu 2026
4. Storage
Lyophilised: refrigerate or freeze per supplier. Reconstituted: refrigerate 2–8 °C, use within guideline window.