Side-by-side · Research reference
LL-37vsSelank
Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.
AHuman-MechanisticHUMAN-REVIEWED15/35 cited
BHuman-MechanisticAUTO-DRAFTED11/40 cited
LL-37
Cathelicidin · Human AMP
Broad-spectrumAntimicrobial activity
Endogenous · Secreted at inflammation sites
Selank
Anxiolytic + Cognitive · Russian Pharma
Intranasal · 2–3×/day during stress / cognitive demand
01Mechanism of Action
Parameter
LL-37
Selank
Primary target
Monoamine system (serotonin / GABA modulation) + immunomodulation via tuftsin domainZaderej 2014
Pathway
hCAP-18 precursor → Proteinase-3 cleavage → LL-37 release → Membrane insertion/disruption
Tuftsin-derived immune signaling + CNS monoamine modulation → reduced anxiety + improved mood / cognitionMedvedev 2007
Downstream effect
Membrane permeabilization, cytokine induction, autophagy, phagosome-lysosome fusion, chemotaxisAhmad 2026Zhang 2026
Anxiolytic + cognitive enhancement; immunomodulation via increased IL-6 + IFN-γMedvedev 2007Zaderej 2014
Origin
Endogenous human cathelicidin (37-AA fragment, residues 134–170 of hCAP-18)
Synthetic 7-AA peptide derived from human tuftsin (immune-system tetrapeptide)Zaderej 2014
Antibody development
—
—
02Dosage Protocols
Parameter
LL-37
Selank
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
—
Evidence basis
In vitro, animal models, human observational
Human-mechanistic + Russian clinical trialsMedvedev 2007
Frequency
—
2–3× per day during stress
Lower / starter dose
—
75 mcg / dose
Duration
—
10–14 day cycles, repeated as needed
Reconstitution
—
Pre-formulated nasal spray (commercial); research vial: bacteriostatic water
Timing
—
Morning + early afternoon preferred
Half-life
—
Short (minutes plasma); CNS effect lasts ~3 hr
04Side Effects & Safety
Parameter
LL-37
Selank
Cytotoxicity (high dose)
Membrane disruption in host cells at supraphysiological concentrations
—
Pro-inflammatory signaling
Can exacerbate inflammation in certain contexts (context-dependent)Pinheiro 2026
—
Theoretical cancer risk
Immunomodulatory roles in tumor microenvironment under investigation
—
Nasal irritation
—
Mild burning or congestion (transient)
Cognitive impairment
—
None — opposite effect (enhancement)
Allergic reaction
—
Rare hypersensitivity
Long-term safety
—
Limited Western RCT data
Pregnancy / OB
—
Avoid — insufficient data
Absolute Contraindications
LL-37
—Selank
- ·Pregnancy / breastfeeding
- ·Hypersensitivity to peptide
Relative Contraindications
LL-37
- ·Active autoimmune disease (theoretical immune dysregulation)
Selank
- ·Active autoimmune disease (theoretical via immunomodulation)
05Administration Protocol
Parameter
LL-37
Selank
1. Natural secretion
LL-37 is constitutively expressed in neutrophils and epithelial cells, cleaved from hCAP-18 by proteinase-3 at sites of infection or inflammation.
Pre-formulated nasal spray (commercial) or research vial reconstituted with bacteriostatic water.
2. Experimental formulations
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.
Intranasal — 1–3 sprays per nostril per dose. Tilt head slightly back.
3. Stability considerations
LL-37 is resistant to pepsin degradation at gastric pH. Synthetic short peptides designed to retain this stability while reducing toxicity.Lu 2026
Morning + early afternoon for cognitive demand; PRN for acute anxiety.
4. Storage
—
Refrigerate after reconstitution; ≤30 days. Light-protected.
5. Caveat
—
Avoid co-administration with strong sedatives or other anxiolytics initially.