Side-by-side · Research reference
GLP-1 (7-37)vsLL-37
Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.
AHuman-MechanisticHUMAN-REVIEWED16/43 cited
BHuman-MechanisticHUMAN-REVIEWED15/35 cited
GLP-1 (7-37)
Incretin Hormone · Native Peptide
Research use only · IV/SC in experimental settings
LL-37
Cathelicidin · Human AMP
Broad-spectrumAntimicrobial activity
Endogenous · Secreted at inflammation sites
01Mechanism of Action
Parameter
GLP-1 (7-37)
LL-37
Primary target
GLP-1 receptor (class B GPCR)Koole 2015
Pathway
GLP-1R activation → cAMP production → PKA signaling → insulin secretion (pancreatic β-cells)Lu 2025Koole 2015
hCAP-18 precursor → Proteinase-3 cleavage → LL-37 release → Membrane insertion/disruption
Downstream effect
Glucose-dependent insulin release, glucagon suppression, delayed gastric emptying, reduced food intakeLu 2025Ding 2017
Membrane permeabilization, cytokine induction, autophagy, phagosome-lysosome fusion, chemotaxisAhmad 2026Zhang 2026
Feedback intact?
Yes — physiological secretion and degradation preserved
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Origin
Endogenous peptide cleaved from proglucagon in intestinal L cells; secreted postprandially
Endogenous human cathelicidin (37-AA fragment, residues 134–170 of hCAP-18)
Antibody development
—
—
02Dosage Protocols
Parameter
GLP-1 (7-37)
LL-37
Clinical use
None — native GLP-1 not used therapeutically
Engineered analogues (semaglutide, liraglutide) used clinically.Friedman 2024
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Research dosing
Variable — 0.1–10 nmol/kg in animal models
Used as reference standard for analogue comparison.
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Modified analogues
t½ extended to 13 h (liraglutide), 165 h (semaglutide)
Via DPP-4 resistance + fatty acid acylation.
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Endogenous expression
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Constitutive in neutrophils, epithelial tissues
Upregulated during infection and inflammation.Pinheiro 2026
Exogenous (experimental)
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Dose varies by study; antimalarial ~10–50 μM in vitro
No FDA-approved exogenous formulation.
Plasma levels (malaria)
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Evidence basis
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In vitro, animal models, human observational
03Metabolic / Fat Loss Evidence
Parameter
GLP-1 (7-37)
LL-37
Mechanism
GLP-1R activation in hypothalamic satiety centers (arcuate nucleus) reduces food intakeLu 2025
Effect demonstrated with long-acting analogues (liraglutide).Lu 2025
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Native GLP-1 efficacy
Minimal — rapid degradation prevents sustained appetite suppression
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Gastric emptying
Delayed in animal models, contributing to satiety
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Body weight impact
Not observed with native GLP-1 — requires analogue formulations
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04Side Effects & Safety
Parameter
GLP-1 (7-37)
LL-37
Native GLP-1
Well-tolerated in research settings; no prolonged exposure data
—
Hypoglycemia risk
Low — insulin secretion is glucose-dependent
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Analogue side effects
Nausea, vomiting, diarrhea (GLP-1R agonists)
Not applicable to native GLP-1 due to non-therapeutic use.
—
GLP-1 resistance
High glucose-induced PKCβ overexpression may reduce GLP-1 responsiveness in endothelial cellsPujadas 2016
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Cytotoxicity (high dose)
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Membrane disruption in host cells at supraphysiological concentrations
Pro-inflammatory signaling
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Can exacerbate inflammation in certain contexts (context-dependent)Pinheiro 2026
Theoretical cancer risk
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Immunomodulatory roles in tumor microenvironment under investigation
Absolute Contraindications
GLP-1 (7-37)
—LL-37
—Relative Contraindications
GLP-1 (7-37)
—LL-37
- ·Active autoimmune disease (theoretical immune dysregulation)
05Administration Protocol
Parameter
GLP-1 (7-37)
LL-37
1. Research use only
Native GLP-1(7-37) is not formulated for therapeutic use. Administered IV or SC in experimental protocols to study GLP-1R pharmacology and as reference standard for analogue development.
LL-37 is constitutively expressed in neutrophils and epithelial cells, cleaved from hCAP-18 by proteinase-3 at sites of infection or inflammation.
2. Storage
Lyophilised peptide stored at -20°C or below. Reconstituted solutions should be prepared fresh and used immediately due to rapid degradation.
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. Clinical alternatives
For therapeutic GLP-1R activation, use FDA-approved long-acting analogues: semaglutide (once weekly), liraglutide (once daily), dulaglutide (once weekly), or exenatide (twice daily or once weekly).
LL-37 is resistant to pepsin degradation at gastric pH. Synthetic short peptides designed to retain this stability while reducing toxicity.Lu 2026