Article

Cerebrolysin: the porcine brain peptide mixture and its research record

Published 26 October 2026 · CognitivePepti Research Desk

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Prepared by: Research Desk. Sources are linked for verification.

Published 26 October 2026

At a glance

What it is: Cerebrolysin is not a single peptide. It is a mixture of low-molecular-weight peptides and amino acids made by controlled enzymatic digestion of pig brain proteins
Where it is used: a 2023 Cochrane review describes wide use in stroke in Russia, Eastern Europe, China and other Asian and post-Soviet countries; it is an approved medicine in some countries
What is in it: a 2015 mass spectrometry study identified 638 distinct peptides in one sample and found no fragments of known neurotrophic factors
Human evidence: Cochrane reviews rate the trial evidence in vascular dementia as very low quality, and in acute ischaemic stroke found little to no difference in death with a possible increase in non-fatal serious adverse events
Record under review: several mouse studies from one University of California San Diego group were retracted in 2025 and 2026, or given an expression of concern, over duplicated or edited figures

What is in the mixture

Because Cerebrolysin is a digest rather than a defined sequence, its composition was long described only in general terms. A Ghent University group profiled an Internet-obtained sample using liquid chromatography coupled to ion trap and ion mobility time-of-flight mass spectrometry, matched against a pig protein database and de novo sequencing (Gevaert et al., 2015, Drug Testing and Analysis).

Peptides identified: 638 unique peptides
Main parent proteins: tubulin alpha and beta chains, actin and myelin basic protein
What was not found: no fragments of GDNF, NGF, BDNF or CNTF, the neurotrophic factors often named in descriptions of the product
Authors' reading: any activity reported in the literature would have to come from other, so far unidentified peptides in the mix

Two points follow for researchers. First, batch-to-batch composition is defined by the manufacturing process rather than by a sequence, so a "Cerebrolysin" sample from an informal source cannot be checked against a single reference standard the way a synthetic peptide can. Second, claims that the mixture "contains" neurotrophic factors are not supported by this analysis.

Dementia trials

Vascular dementia: a Cochrane review (Cui et al., 2019) found six randomised trials with 597 participants and no new trials since its 2013 version. Pooled cognitive scores favoured Cerebrolysin (standardised mean difference 0.36, 95% CI 0.13–0.58; three studies, 420 people), but the reviewers rated all of the evidence as very low quality, noted high risk of bias and industry funding wherever funding was reported, and concluded that the supporting evidence base is weak and any effect may be too small to matter
Alzheimer's disease: a meta-analysis of six randomised trials (Gauthier et al., 2015) reported a cognitive difference from placebo at 4 weeks that was not statistically significant at 6 months (standardised mean difference −0.37, 95% CI −0.90 to 0.16). The analysis was co-authored by researchers linked to the manufacturer
Single trial example: Alvarez et al. (2011), in the European Journal of Neurology, reported a subgroup analysis of a trial comparing three Cerebrolysin regimens with placebo in moderate to moderately severe Alzheimer's disease; its authors also called for larger trials

Stroke trials

Cochrane review: Ziganshina et al. (2023) pooled seven randomised trials with 1,773 participants started within 48 hours of acute ischaemic stroke, including one trial of Cortexin, a similar mixture derived from cattle brain
Death: little to no difference in all-cause death (risk ratio 0.96, 95% CI 0.65–1.41; moderate-certainty evidence)
Serious adverse events: little to no difference overall (risk ratio 1.16, 95% CI 0.81–1.66), but a potential increase in non-fatal serious adverse events (risk ratio 2.39, 95% CI 1.10–5.23; three trials, 1,335 participants; moderate certainty)
Bias: the manufacturer supported three of the multicentre trials, and incomplete outcome data put four trials at high risk of bias
Motor function studies: a pre-planned pooled analysis of the CARS-1 and CARS-2 trials (Guekht et al., 2017, Neurological Sciences), with 442 participants, reported better arm-function scores at day 90 than placebo. Several of its authors were employees of, consultants to, or grant recipients of the manufacturer, EVER Neuro Pharma

The animal studies and the retractions

Much of the mechanistic story for Cerebrolysin, including effects on amyloid processing, tau pathology and new neuron formation in transgenic mice, came from a long-running collaboration between Eliezer Masliah's laboratory at UC San Diego and the manufacturer. Part of that record has now been withdrawn:

March 2025: BMC Neuroscience retracted a 2015 study of Cerebrolysin in a three-repeat tau mouse model after finding overlapping image panels that were meant to show animals under different conditions (retraction note)
December 2025: the same journal retracted a 2014 study of Cerebrolysin and mitochondrial structure in a tauopathy model over overlapping Western blot bands and an edited background (retraction note)
March 2026: Acta Neuropathologica published an editorial expression of concern on a 2009 study in APP-transgenic mice injected with mutant tau (notice)

In both BMC Neuroscience notices the editor stated that they no longer had confidence in the integrity of the research. Researchers citing the older transgenic-mouse literature on Cerebrolysin should check each paper's current status on PubMed before relying on it.

Limitations of the evidence

Undefined composition: results from one product batch, or from Cortexin, may not carry over to another preparation
Sponsor involvement: most randomised trials and several meta-analyses involve the manufacturer as funder, supplier or co-author
Small and short trials: the dementia trials are small, with follow-up from 15 days to three years and high risk of bias
Harms signal: the stroke review found a potential increase in non-fatal serious adverse events
Retracted preclinical work: key mechanistic mouse studies have been retracted or flagged, and independent replication is limited

Key terms

Hydrolysate: a mixture produced by breaking proteins into smaller peptides and amino acids with enzymes or acid
Neurotrophic factor: a protein such as BDNF or NGF that supports the survival and growth of neurons
Standardised mean difference: an effect size that lets trials using different rating scales be pooled
Expression of concern: a journal notice that a paper's reliability is under question, short of retraction

Supplier

Purita is a store that sells peptides for laboratory research use only. It does not list Cerebrolysin; its neurological category lists research peptides such as Semax, Selank and DSIP, labelled for research use only and not for human or animal administration.

Purita neurological category

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