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

LivagenvsP21

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
BAnimal-MechanisticHUMAN-REVIEWED8/36 cited
Livagen
Khavinson Bioregulator · Hepatoprotective Tetrapeptide
50%Dipeptidase inhibitionTimofeeva 2005
Oral / SQRoutes tested
LiverTarget tissueKhavinson 2001
Oral or SQ · Tissue-specific to liver
P21
CNTF-Derived Neuropeptide · Animal Model Evidence
CNTFR/gp130Primary receptorGuo 2022
Animal onlyEvidence level
NeurogenesisPrimary effectJia 2020Mottolese 2024
SQ · Site unspecified · Frequency unknown

01Mechanism of Action

Parameter
Livagen
P21
Primary target
Hepatocyte protein synthesis machineryBrodskiĭ 2001
CNTF receptor alpha (CNTFRα) / LIF receptor (LIFR) / gp130 complex on neural stem cells
Pathway
Tissue-specific bioregulator → Hepatocyte stimulation → Protein synthesis normalizationBrodskiĭ 2001Khavinson 2001
CNTF mimetic → CNTFRα/LIFR/gp130 heterotrimer → JAK/STAT3 signaling → neurogenesis, stem cell proliferation, neuroprotection
Downstream effect
Age-dependent enzyme normalization, hepatoprotection in fibrosis/hepatitis models, elevated protein synthesis in senescent hepatocytes
Increased neural stem cell self-renewal, globose basal cell activation (Mash1+ cells), olfactory sensory neuron regeneration, hippocampal neurogenesis, neuroprotection in developmental disorders
Feedback intact?
Origin
Directed chemical synthesis from amino acid analysis of liver polypeptide preparations (Ventvil)
Small-molecule peptide mimetic derived from full-length ciliary neurotrophic factor (CNTF), designed to retain receptor activation with improved pharmacokineticsMottolese 2024
Antibody development

02Dosage Protocols

Parameter
Livagen
P21
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
Presumed subcutaneous or intraperitoneal (animal studies)
Evidence basis
Animal models (rats, 1–24 months age); in vitro hepatocyte cultureTimofeeva 2005Brodskiĭ 2001Khavinson 2002
Animal models only
CDKL5 KO mice, methimazole-induced olfactory injury, CNTF-/- knockout models.Mottolese 2024Cox 2026Jia 2020
Human data
None in provided literature
Human dosing
No established protocol
No clinical trial data available.
Animal models (mice)
Dose and route not specified in abstractsMottolese 2024Jia 2020
In vitro and in vivo studies demonstrate efficacy; precise dosing protocols not disclosed.
Duration
Not specified

04Side Effects & Safety

Parameter
Livagen
P21
Reported adverse effects
None documented in animal studies
Human safety data
No human trials in provided literature
None available
No clinical trials in humans.
Peptide hydrolysis
Weakly hydrolyzed; minimal breakdown by intestinal enzymesTimofeeva 2005
Animal tolerability
Well-tolerated in mouse models; no toxicity reported in available abstracts
Theoretical risks
Uncontrolled stem cell proliferation, immune response to peptide, unknown long-term CNS effects
Absolute Contraindications
Livagen
P21
  • ·Use in humans not validated
Relative Contraindications
Livagen
P21
  • ·Active malignancy (theoretical — neurotrophic signaling may affect tumour growth)
  • ·Pregnancy or lactation (no safety data)

05Administration Protocol

Parameter
Livagen
P21
1. Route selection
Oral administration supported by peptidase resistance. Subcutaneous route used in organotypic culture experiments.Timofeeva 2005Khavinson 2001
Not established. No FDA approval, no clinical trial data.
2. Timing
No specific timing documented. Two-week protocols used in animal models with daily administration.Timofeeva 2005
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. Age-dependent response
Elderly individuals may exhibit different enzyme normalization patterns than younger cohorts, based on rat age-stratified findings.Timofeeva 2005