Side-by-side · Research reference
CortagenvsP21
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
BAnimal-MechanisticHUMAN-REVIEWED8/36 cited
Cortagen
Bioregulatory Tetrapeptide · Khavinson-School
Injectable · Animal models
P21
CNTF-Derived Neuropeptide · Animal Model Evidence
Animal onlyEvidence level
SQ · Site unspecified · Frequency unknown
01Mechanism of Action
Parameter
Cortagen
P21
Primary target
Cerebral cortex tissue — molecular targets under investigation
CNTF receptor alpha (CNTFRα) / LIF receptor (LIFR) / gp130 complex on neural stem cells
Pathway
Antioxidant pathway modulation — suppression of LPO cascade, reduction of protein oxidative modificationKozina 2007
CNTF mimetic → CNTFRα/LIFR/gp130 heterotrimer → JAK/STAT3 signaling → neurogenesis, stem cell proliferation, neuroprotection
Downstream effect
Decreased lipid peroxidation products, reduced oxidative protein damage, altered gene expression in cardiac tissueKozina 2007Anisimov 2004
Increased neural stem cell self-renewal, globose basal cell activation (Mash1+ cells), olfactory sensory neuron regeneration, hippocampal neurogenesis, neuroprotection in developmental disorders
Feedback intact?
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Origin
Synthetic tetrapeptide derived from amino acid analysis of natural brain cortex peptide preparation CortexinAnisimov 2004
Small-molecule peptide mimetic derived from full-length ciliary neurotrophic factor (CNTF), designed to retain receptor activation with improved pharmacokineticsMottolese 2024
Antibody development
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02Dosage Protocols
Parameter
Cortagen
P21
Animal model dose (rat)
Injection protocol (dose not specified in abstracts)
Multiple injections over study period.
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Avian model dose (chicken)
40-day injection courseKuznik 2008
Compared to epithalon in hypophysectomized and aged birds.
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Human peripheral nerve study
Therapeutic course (protocol details not provided)
Posttraumatic recovery context — reference cited but not detailed.
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Evidence basis
Animal mechanistic studies
Animal models only
CDKL5 KO mice, methimazole-induced olfactory injury, CNTF-/- knockout models.Mottolese 2024Cox 2026Jia 2020
Route
Injectable (inferred from animal protocols)
Presumed subcutaneous or intraperitoneal (animal studies)
Human dosing
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No established protocol
No clinical trial data available.
Animal models (mice)
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Dose and route not specified in abstractsMottolese 2024Jia 2020
In vitro and in vivo studies demonstrate efficacy; precise dosing protocols not disclosed.
Duration
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Not specified
04Side Effects & Safety
Parameter
Cortagen
P21
Antioxidant suppression
Suppression of antioxidant activity noted alongside LPO reductionKozina 2007
Mechanism unclear — possible homeostatic adaptation.
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Immune/hemostasis effects
No effect on immunity or hemostasis parameters in avian hypophysectomy model (unlike epithalon)Kuznik 2008
Epithalon reversed deficits; cortagen did not.
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Human safety data
No adverse events reported in peripheral nerve recovery context
Limited detail in available abstracts.
None available
No clinical trials in humans.
Animal tolerability
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Well-tolerated in mouse models; no toxicity reported in available abstracts
Theoretical risks
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Uncontrolled stem cell proliferation, immune response to peptide, unknown long-term CNS effects
Absolute Contraindications
Cortagen
—P21
- ·Use in humans not validated
Relative Contraindications
Cortagen
—P21
- ·Active malignancy (theoretical — neurotrophic signaling may affect tumour growth)
- ·Pregnancy or lactation (no safety data)
05Administration Protocol
Parameter
Cortagen
P21
1. Preparation
Reconstitute lyophilised peptide with bacteriostatic water per supplier protocol. Exact volumes depend on concentration supplied.
Not established. No FDA approval, no clinical trial data.
2. Injection site
Subcutaneous injection typical for bioregulatory peptides — abdomen or thigh. Rotate sites.
In vivo studies used systemic administration (route not specified in abstracts) in mouse models of neurodegeneration, olfactory injury, and CDKL5 deficiency disorder. In vitro studies used primary cell cultures.
3. Timing
Animal protocols used repeated dosing over weeks. Human timing not established — evening administration common in Khavinson tradition.
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4. Storage
Lyophilised: refrigerate or freeze per supplier. Reconstituted: refrigerate 2–8 °C, use within guideline window.
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