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AMIRAVOResearch Library

Cerebrolysin vs Semax

Cerebrolysin and Semax are both used in some countries after stroke, but one is a mixture extracted from pig brain and the other is a single synthetic peptide 1,11. Cerebrolysin holds an Austrian marketing authorisation for supportive treatment of cerebrovascular disorders, and its stroke trials have been pooled in Cochrane reviews 1,2. Semax is a heptapeptide analogue of an ACTH fragment, listed in a 2022 review as a nootropic drug registered in the Russian Federation, with a smaller, mostly Russian clinical literature 8,11. Neither is FDA-approved 7,12.

Unbranded reference vial illustrating Cerebrolysin; not an actual product
Cerebrolysin
Approved outside the US
Unbranded reference vial illustrating Semax; not an actual product
Semax
Approved outside the US

Side by side

FieldCerebrolysinSemax
ClassProteolytic peptide fraction from porcine brain protein (a mixture, not a single compound) 1Single synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) 8,11
Origin and structureShort-chain peptides similar or identical to endogenous peptides, derived from pig brain protein 1Analogue of the ACTH(4-10) fragment, synthesised at the Institute of Molecular Genetics, Russian Academy of Sciences 8,11
Proposed mechanismLabel describes neurotrophic and synaptic-plasticity effects and reduced infarct volume in animal ischaemia models 1In rats, raised BDNF protein in basal forebrain and bound specific brain membrane sites 8
Half-lifeNot measurable directly; the Austrian label states a neurotrophic effect is detectable in plasma up to 24 hours after a single administration 1Not located; the FDA found no human pharmacokinetic studies by any route (2026 review) 16
Highest human trial phasePhase 4 (post-authorisation) randomised trials registered, including the 1,070-patient CASTA trial 5,6Russian clinical studies without a stated phase 9,10; no studies found on ClinicalTrials.gov 14
FDA statusNot FDA-approved; no Drugs@FDA record returned (queried 24 October 2026) 7; not in any 503A nomination category as updated 14 May 2026 15Not FDA-approved; listed among withdrawn category 2 compounding nominations with immunogenicity and impurity concerns (page current 22 April 2026) 12; in July 2026 the FDA proposed it not be added to the 503A compounding bulks list 16
Published human outcomesCochrane: Cerebrolysin or similar agents probably make little to no difference to all-cause death in acute ischaemic stroke (7 RCTs, 1,773 participants) 2; very low-quality evidence of cognitive change in vascular dementia 3Small Russian stroke studies reported changes in plasma BDNF and functional scores 9,10
Safety signalsCochrane found more people with non-fatal serious adverse events (RR 2.39, moderate certainty) 2; label contraindicates status epilepticus and severe kidney impairment 1FDA found insufficient clinical information to characterise its safety and noted that in mice it potentiated amphetamine-induced striatal dopamine release 16
WADA statusNot named on the 2026 Prohibited List 13Not named on the 2026 Prohibited List 13
Who funded the evidenceManufacturer support for three multicentre stroke trials; industry funding in all vascular dementia trials that reported it 2,3Mostly Russian academic institutes linked to the developer 8,11

Cerebrolysin: what the data says

Cerebrolysin is authorised in Austria (marketing authorisation holder EVER Neuro Pharma GmbH) for supportive treatment of cerebrovascular disorders, including Alzheimer-type and vascular dementia, post-stroke deficits and head injury in adults 1. Because it is a mixture of endogenous-like peptides, the label states that pharmacokinetic parameters cannot be measured directly 1.

In humans, a 2023 Cochrane review of seven randomised trials (1,773 participants) in acute ischaemic stroke found that Cerebrolysin or similar agents probably make little to no difference to all-cause death, with an increase in non-fatal serious adverse events 2. The large CASTA trial (1,070 patients) was neutral on its primary endpoint 5, while the smaller exploratory CARS trial in early rehabilitation reported higher arm-function scores versus placebo 4. A Cochrane review in vascular dementia rated the cognitive and global findings as very low-quality evidence with high risk of bias 3.

Semax: what the data says

Semax evidence comes mostly from Russian groups. In rats (animal data), intranasal Semax raised BDNF protein levels in the basal forebrain 8. A 2022 review lists it among 14 peptide drugs registered in the Russian Federation, classed as a nootropic 11.

Human data are limited to small Russian clinical studies. In 110 people after ischaemic stroke, those given Semax had higher plasma BDNF and faster Barthel-index recovery 9. A 1997 study comparing 30 treated patients with 80 controls in acute stroke reported faster recovery of some neurological functions 10. No Semax studies were returned by a ClinicalTrials.gov search 14.

Key research differences

  • Composition: Cerebrolysin is a peptide fraction from pig brain protein, whereas Semax is one defined synthetic heptapeptide 1,8.
  • Evidence base: Cerebrolysin has multicentre placebo-controlled trials pooled in Cochrane reviews 2,3, while Semax has smaller, mostly Russian-language studies 9,10.
  • Trial outcomes: the pooled Cerebrolysin stroke evidence shows probably little to no effect on death and more non-fatal serious adverse events 2; no pooled analysis was located for Semax.
  • Authorisation: Cerebrolysin holds an Austrian marketing authorisation 1, while Semax is listed as registered in Russia 11.
  • FDA compounding: Semax appears among withdrawn category 2 nominations 12, while Cerebrolysin does not appear in any 503A nomination category 15.

Where the evidence is limited

No trial has compared Cerebrolysin with Semax. Cerebrolysin trials are larger but often manufacturer-supported and judged by Cochrane reviewers to carry unclear or high risk of bias 2,3. Semax studies are small, often non-randomised and published mainly in Russian 9,10. The two products are given by different routes, in different settings and at different times after stroke, so results cannot be set side by side.

Frequently asked questions

Are Cerebrolysin and Semax the same kind of product?
No. Cerebrolysin is a peptide mixture derived from pig brain protein, while Semax is a single synthetic ACTH-fragment analogue 1,8.
Which has more clinical trial evidence?
Cerebrolysin has more, including seven randomised stroke trials in a 2023 Cochrane review 2. Semax evidence consists of smaller Russian studies 9,10.
What did the Cochrane review find for Cerebrolysin in stroke?
It found probably little to no difference in all-cause death and an increase in non-fatal serious adverse events, both at moderate certainty 2.
Are either approved in the United States?
No. Drugs@FDA returned no Cerebrolysin record 7, and the FDA lists Semax among withdrawn compounding nominations with limited safety information 12. In a July 2026 briefing document, the FDA also proposed that Semax not be added to the 503A bulks list 16.

References

  1. Cerebrolysin parenterale Lösung: Fachinformation (summary of product characteristics), Zulassungsnummer 1-21380, Stand März 2021 BASG (Austrian Federal Office for Safety in Health Care). 2021
  2. Cerebrolysin for acute ischaemic stroke Cochrane Database of Systematic Reviews. 2023
  3. Cerebrolysin for vascular dementia Cochrane Database of Systematic Reviews. 2019
  4. Cerebrolysin and Recovery After Stroke (CARS): A Randomized, Placebo-Controlled, Double-Blind, Multicenter Trial Stroke. 2016
  5. Cerebrolysin in patients with acute ischemic stroke in Asia: results of a double-blind, placebo-controlled randomized trial Stroke. 2012
  6. ClinicalTrials.gov registry search: cerebrolysin (43 studies, including phase 4 trials such as NCT00868283; searched 24 October 2026) ClinicalTrials.gov. 2026
  7. Drugs@FDA via openFDA: query for cerebrolysin (no matching application, queried 24 October 2026) openFDA. 2026
  8. Semax, an analogue of adrenocorticotropin (4-10), binds specifically and increases levels of brain-derived neurotrophic factor protein in rat basal forebrain Journal of Neurochemistry. 2006
  9. The efficacy of semax in the treatment of patients at different stages of ischemic stroke (in Russian) Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova. 2018
  10. Effectiveness of semax in acute period of hemispheric ischemic stroke: a clinical and electrophysiological study (in Russian) Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova. 1997
  11. Development of Peptide Biopharmaceuticals in Russia Pharmaceutics. 2022
  12. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (content current as of 04/22/2026) FDA (Human Drug Compounding). 2026
  13. Prohibited List (2026 List, in force 1 January 2026) World Anti-Doping Agency. 2026
  14. ClinicalTrials.gov registry search: semax (no registered studies returned, searched 24 October 2026) ClinicalTrials.gov. 2026
  15. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act (updated May 14, 2026) FDA. 2026
  16. FDA Briefing Document, Pharmacy Compounding Advisory Committee, July 23-24, 2026: Semax-Related Bulk Drug Substances (Semax (free base) and Semax acetate) FDA. 2026

For research use only. Not for human or veterinary use. Not a drug, food, or dietary supplement. This page compares published research and is not medical advice or a recommendation.