Peptide Comparison
CortexinvsSelank
Bovine cerebral cortex-derived polypeptide preparation with nootropic, neuroprotective, and antioxidant properties used clinically in Russia for cerebrovascular disorders, cognitive impairment, and pediatric neurology
A clever brain-boosting peptide derived from your immune system's natural tuftsin molecule—it calms anxiety and sharpens your mind without the drowsiness or addiction risks of traditional anti-anxiety medications.
At a Glance
Quick
comparison
Dose Range
Cortexin
5–10 mg
Selank
250–500 mcg
Frequency
Cortexin
Once daily
Selank
Once daily
Administration
Cortexin
Intramuscular (IM) injection
Selank
Intranasal
Cycle Length
Cortexin
8-12 weeks
Selank
4-6 weeks
Onset Speed
Cortexin
Moderate (1-2 weeks)
Selank
Rapid (hours to days)
Evidence Level
Cortexin
Limited human trials
Selank
Limited human trials
Efficacy
Benefit
ratings
Recovery
Cognitive
Anxiety Relief
Cognitive Enhancement
Immune Support
Technical Data
Compound
specifications
Cortexin
Molecular Formula
Complex mixture — no single molecular formula (contains multiple low molecular weight polypeptide fractions, L-amino acids, vitamins, and trace elements)
Molecular Weight
Low molecular weight water-soluble polypeptide fractions — specific molecular weight distribution varies as a complex biological mixture
Half-Life
Approximately 2-6 hours (varies by route of administration)
Bioavailability
~85-100% (intramuscular injection)
CAS Number
Not assigned (biological mixture)
Selank
Molecular Formula
C33H57N11O9
Molecular Weight
751.9 g/mol
Half-Life
2-3 minutes (plasma); effects last hours due to downstream signaling
Bioavailability
High intranasal absorption; near 100% subcutaneous
CAS Number
129954-34-3
Protocols
Dosing
tiers
Cortexin
Selank
Applications
Best
suited for
Cortexin
Cognitive support in chronic cerebral ischemia and cerebrovascular disease
Cortexin is particularly well-suited for individuals focused on cognitive support in chronic cerebral ischemia and cerebrovascular disease. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Neuroprotection and neurorecovery following stroke or traumatic brain injury
Cortexin is particularly well-suited for individuals focused on neuroprotection and neurorecovery following stroke or traumatic brain injury. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Pediatric neurology including cerebral palsy and developmental delays
Cortexin is particularly well-suited for individuals focused on pediatric neurology including cerebral palsy and developmental delays. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Adjunctive treatment in epilepsy management
Cortexin is particularly well-suited for individuals focused on adjunctive treatment in epilepsy management. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Selank
Anxiety Without the Fog
If traditional anti-anxiety medications leave you feeling sedated, foggy, or 'not yourself,' Selank offers a refreshing alternative. It calms anxious thoughts while keeping your mind sharp—like turning down the volume on worry without muting your brain.
Cognitive Performers
Students, professionals, and anyone facing demanding mental tasks love Selank for its dual action. It simultaneously reduces performance anxiety while enhancing memory and focus—the best of both worlds when you need to think clearly under pressure.
Stress Resilience Seekers
Chronic stress wreaks havoc on your brain. Selank helps protect against stress-induced cognitive decline by supporting BDNF levels and modulating your stress response. Think of it as building a buffer between you and life's daily pressures.
Natural Approach Enthusiasts
Derived from tuftsin—a natural peptide your own immune system produces—Selank appeals to those seeking more 'natural' solutions. It works with your body's existing systems rather than overriding them like synthetic drugs.
Safety Profile
Side
effects
Cortexin
Common
- Injection site reactions
- Headache
- Dizziness
- Nausea
- Agitation or restlessness
- Transient blood pressure changes
Uncommon
- Allergic reactions
Serious
- Severe allergic reaction / Anaphylaxis
Selank
Common
- Nasal irritation
- Mild fatigue
- Mild headache
- Injection site redness
Uncommon
- Vivid dreams
- Dizziness
Serious
- Allergic reaction
Research Status
Safety
& evidence
Cortexin
Evidence Level
Limited human trials
FDA Status
Research compound
Safety Overview
Cortexin is a porcine brain-derived polypeptide preparation used in Russian neurology that is not FDA-approved and has no Western rigorous safety data. As an undefined mixture of peptides and proteins extracted from animal brains, batch standardization and quality control are not guaranteed. Concerns include potential transmissible spongiform encephalopathy (TSE/prion) risk from animal CNS tissue, although documented cases have not been reported. Allergic reactions to porcine proteins are possible. No formal human safety assessments, toxicology studies, or clinical trials by modern regulatory standards have been conducted. Use in Western countries is essentially non-existent due to regulatory limitations on animal-derived neurological products.
Contraindications
- xKnown hypersensitivity to Cortexin or any component including glycine stabilizer
- xAllergy to bovine-derived biological products
- xPregnancy — insufficient safety data for use during pregnancy
- xBreastfeeding — insufficient data on excretion into breast milk
Selank
Evidence Level
Limited human trials
FDA Status
Research compound
Safety Overview
Selank has demonstrated a favorable safety profile across multiple Russian clinical studies spanning over two decades. In human trials comparing Selank to traditional anxiolytics like phenazepam, Selank showed comparable anti-anxiety effects with significantly better tolerability and no sedation, dependence, or memory impairment. The peptide has been approved for clinical use in Russia since the 1990s for anxiety and neurasthenia.
Contraindications
- xPregnancy or planning to become pregnant
- xCurrently breastfeeding
- xKnown allergy to peptide components
- xChildren and adolescents
- xSevere psychiatric disorders requiring immediate intervention
Decision Guide
Which is
right for you?
Choose Cortexin if...
- Cognitive support in chronic cerebral ischemia and cerebrovascular disease
- Neuroprotection and neurorecovery following stroke or traumatic brain injury
- Pediatric neurology including cerebral palsy and developmental delays
- Adjunctive treatment in epilepsy management
Choose Selank if...
- Anxiety relief without sedation
- Cognitive enhancement and focus
- Memory improvement
- Stress resilience