Cerebrolysin vs Selank
Porcine brain-derived neuropeptide preparation containing bioactive peptide fragments of neurotrophic factors, used clinically in over 40 countries for stroke recovery, traumatic brain injury, and cognitive impairment
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 [1][4].
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team · Editorial standards
Quick comparison
Dose range
Cerebrolysin
20–30 mL
Selank
900–2700 mcg/day
Frequency
Cerebrolysin
Once daily
Selank
3 times daily
Administration
Cerebrolysin
Intravenous (IV) injection or infusion
Selank
Intranasal
Cycle length
Cerebrolysin
8-12 weeks
Selank
14 days, repeatable after 1-3 weeks
Onset speed
Cerebrolysin
Moderate (1-2 weeks)
Selank
Rapid (hours to days)
Evidence level
Cerebrolysin
Moderate human trials (Phase 1-2)
Selank
Limited human trials
Benefit ratings
Stroke Recovery
Alzheimer's Support
Brain Injury Healing
Anxiety Relief
Cognitive Enhancement
Immune Support
Compound specifications
Cerebrolysin
Molecular formula
Complex mixture — no single molecular formula (contains multiple peptide fragments and free amino acids derived from porcine brain proteins)
Molecular weight
Bioactive peptide components are all below 10 kDa (10,000 Da); the preparation contains a spectrum of peptide sizes
Half-life
Approximately 15-30 minutes (IV 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
Dosing compared
Cerebrolysin
Intravenous
10 mL
Once daily · 10-20 day course, repeated every 3-6 months
A gentle starting dose given as a slow IV infusion (often diluted in saline). Used in dementia and recovery programs. [6][7]
20-30 mL
Once daily · 10-21 day course, repeated in cycles
The common clinical dose. Trials in vascular dementia used 20 mL daily, and stroke trials used 30 mL daily (diluted to about 100 mL saline) infused over ~30 minutes. [6][7]
30-50 mL
Once daily · 10-21 days for stroke or severe brain injury
The higher end used for acute stroke and severe traumatic brain injury, given as a diluted IV infusion under medical supervision. [7]
Intramuscular
5-10 mL
Once daily · Up to 10-20 days per course
For smaller doses, Cerebrolysin can be given as an intramuscular injection (no more than ~5 mL per injection site). Often used for milder cases or maintenance between IV cycles. [7]
Selank
Intranasal
Registered label dose
900 mcg/day total (3 doses of 300 mcg)
2 drops in each nostril, 3 times daily · Registered label dose
The approved dose on the Russian registration (ЛРС-003338/09): 2 drops in each nostril, three times a day. At 75 mcg per drop that is 300 mcg per administration and 900 mcg across the day, taken as a 14-day course that can be repeated after 1-3 weeks [7]. Human evidence, registered label.
Highest dose studied
2,700 mcg/day total (3 doses of 900 mcg)
900 mcg (12 drops) 3 times daily · Highest dose studied
The top of the range the developing institute describes as optimal — single doses of 300-900 mcg, 900-2,700 mcg a day split across three administrations — and the dose used in the multicentre generalised-anxiety and neurasthenia trial, where 2,700 mcg/day was compared against medazepam 30 mg/day for 14 days [9]. Because the label caps a single administration at 2-3 drops per nostril, a 900 mcg dose is given as 2-3 drops per nostril with the rest 15 minutes later [7]. Human evidence, trial protocol.
Subcutaneous injection
Community suggestion — not a studied protocol
300-500 mcg per injection
Once daily · Community suggestion — not a studied protocol
Community-reported, not peer-reviewed. No human study has tested subcutaneous selank and the registered product is nasal drops only [7], so this range comes from community and clinical-practice reports rather than a trial — there is no published safety or effectiveness data behind it. Two things worth knowing before choosing the route. The nasal spray is absorbed almost completely, with 92.8% of the dose reaching the bloodstream within 30 seconds [7], so injecting is not a way to get more of the peptide in. And in mice, the injected and intranasal routes did not act the same: injection shifted GABA-receptor binding while the nasal route shifted NMDA-receptor binding instead, which the authors put down to how each route is absorbed and broken down [13]. That is animal work, and no one has checked whether the same split happens in people.
Best suited for
Cerebrolysin
Post-stroke neurorecovery and rehabilitation support
Cerebrolysin is particularly well-suited for individuals focused on post-stroke neurorecovery and rehabilitation support. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach [2][13].
Cognitive support in Alzheimer's disease and vascular dementia
Cerebrolysin is particularly well-suited for individuals focused on cognitive support in alzheimer's disease and vascular dementia. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach [1][6].
Traumatic brain injury recovery and neuroprotection
Cerebrolysin is particularly well-suited for individuals focused on traumatic brain injury recovery and neuroprotection. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach [14].
Age-related cognitive decline and mild cognitive impairment
Cerebrolysin is particularly well-suited for individuals focused on age-related cognitive decline and mild cognitive impairment. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach [1].
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 [1].
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 [1][2].
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 [2]. 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 [4]. It works with your body's existing systems rather than overriding them like synthetic drugs.
Side effects
Cerebrolysin
Common
- Injection site reactions
- Headache
- Dizziness and vertigo
- Nausea and gastrointestinal discomfort
- Agitation or restlessness
- Fever
Uncommon
- Allergic reaction
Serious
- Severe hypersensitivity reaction
Selank
Common
- Nasal irritation
- Mild fatigue
- Mild headache
- Injection site redness
Uncommon
- Vivid dreams
- Dizziness
Serious
- Allergic reaction
Safety & evidence
Cerebrolysin
Evidence level
Moderate human trials (Phase 1-2)
FDA status
Research compound
Safety overview
Cerebrolysin is an FDA-unregulated neuroprotective agent consisting of porcine brain-derived peptides and amino acids that has been used primarily in Eastern Europe and Asia. [8][12] Safety data is limited to observational clinical use and small open-label trials rather than rigorous randomized controlled trials with formal safety monitoring. As a complex mixture of undefined peptide fragments from animal sources, batch consistency and sterility cannot be guaranteed without pharmaceutical manufacturing standards. Potential allergic reactions to porcine proteins and transmissible spongiform encephalopathy (TSE) risks from animal-derived components have not been adequately ruled out.
Contraindications
- Known hypersensitivity to Cerebrolysin or porcine-derived products
- Severe renal impairment or renal failure
- Status epilepticus or uncontrolled epilepsy
- Pregnancy and breastfeeding — insufficient safety data
Selank
Evidence level
Limited human trials
FDA status
Research compound
Safety overview
The safety record comes from small Russian trials, and the numbers are worth seeing. In the 62-person generalised-anxiety and neurasthenia trial, 30 people took selank at 2,700 mcg a day and 32 took medazepam 30 mg a day for 14 days; the two calmed anxiety about equally, and selank also reduced fatigue where the benzodiazepine did not [9]. A second trial of 60 people with phobic-anxiety and somatoform disorders compared it with phenazepam and reported a clear anxiolytic effect that lasted about a week after the last dose [3]. The registered label lists only two side effects — an unpleasant taste when the drops run from the nose into the throat, and allergic reactions in people sensitive to the ingredients — and records no cases of overdose, which it attributes to how fast the peptide breaks down [7]. Neither trial published a per-arm adverse-event rate, so there is no side-effect percentage to compare against placebo.
Contraindications
- Pregnancy or planning to become pregnant
- Currently breastfeeding
- Known allergy to peptide components
- Children and adolescents
- Severe psychiatric disorders requiring immediate intervention
Which is right for you?
Choose Cerebrolysin if...
- Post-stroke neurorecovery and rehabilitation support
- Cognitive support in Alzheimer's disease and vascular dementia
- Traumatic brain injury recovery and neuroprotection
- Age-related cognitive decline and mild cognitive impairment
Choose Selank if...
- Anxiety relief without sedation
- Cognitive enhancement and focus
- Memory improvement
- Stress resilience