Cerebrolysin Research, Specifications & Scientific Information

Introduction

Cerebrolysin is the oldest and most heavily trialled compound in this library, and the only one that is not a compound. It is a mixture of low-molecular-weight peptides and free amino acids produced by enzymatic breakdown of purified porcine brain protein, and it has been given to tens of thousands of people in randomised trials across stroke, head trauma and dementia ^[1].

Its evidence base divides cleanly along a line that is worth naming at the outset. The individual trials, most of them multicentre and several of them large, report favourable results on multidimensional outcome measures and describe themselves, often explicitly, as exploratory ^{[5, 7]}. The systematic reviews that pool those trials against prespecified hard outcomes — death, serious adverse events — and grade the certainty of the result reach a different conclusion: no benefit demonstrated on mortality after ischaemic stroke, and a signal of increased non-fatal serious adverse events ^[1].

Both readings are real, both are in the peer-reviewed literature, and this page reports both without choosing between them. It also reports the structural fact that sits underneath everything else: nobody knows what in the mixture is doing the work, because no active constituent has been isolated.

What Is Cerebrolysin?

Cerebrolysin is a biologically derived mixture, not a synthetic peptide. It is produced by the controlled enzymatic breakdown of purified protein from porcine brain, and the product is an aqueous solution containing low-molecular-weight peptides together with free amino acids ^[1]. In the trial protocols it is administered intravenously or intramuscularly and is measured in millilitres of solution, not in milligrams of an active substance — a detail that follows directly from the absence of a defined active substance.

The regulatory situation is split. It is registered as a medicine and widely administered in the Russian Federation, Eastern Europe, China and other Asian and post-Soviet countries ^[1]. It has never been approved by the U.S. Food and Drug Administration for any indication, and no marketing application for it is on record in the United States. Registration in one jurisdiction is a decision by that jurisdiction's regulator and carries no weight elsewhere.

Three descriptive facts make this entry unlike the rest of the library:

• There is no sequence. The specification table below records the amino-acid sequence, molecular formula and molecular weight as not publicly characterised, because for a mixture those fields have no value to record.
• There is no PubChem entry, since PubChem indexes defined chemical structures. The FDA/NCATS Global Substance Registration System does carry it, classified as structurally diverse, under UNII 37KZM6S21G and CAS registry number 12656-61-0.
• Batch equivalence is a manufacturing claim, not an analytical one. With no defined structure to confirm, consistency between lots rests on the process and on the manufacturer's own release testing.

Cerebrolysin Specifications

Cerebrolysin has no molecular formula, no molecular mass and no amino-acid sequence, because it is not a compound. It is a mixture of low-molecular-weight peptides and free amino acids derived from porcine brain, supplied as an aqueous solution for intravenous or intramuscular administration and quantified by volume rather than by mass of an active substance. The FDA/NCATS Global Substance Registration System classifies it as structurally diverse and records it under UNII 37KZM6S21G with CAS registry number 12656-61-0; no PubChem compound identifier exists for it, because PubChem indexes defined chemical structures. Every specification field on this page that asks for a structural value is therefore published as not publicly characterised, and that is the correct answer rather than a gap. The practical consequence is that batch-to-batch equivalence rests on the manufacturing process and on the manufacturer's release testing, not on a structure that can be confirmed independently.

Values that a public register does not carry are shown as not publicly characterised rather than estimated. Identifiers are reference values; the certificate of analysis supplied with a laboratory order is the record for a given lot.

How Does Cerebrolysin Work?

The honest answer is that nobody has established this, and the reason is structural rather than a gap in effort.

The account given for the preparation is that its peptide fraction has neurotrophic and neuroprotective activity — that it mimics, in some general way, the endogenous growth factors that support neuronal survival and plasticity ^[1]. That is a class-level hypothesis rather than a mechanism. No constituent peptide has been isolated and shown to account for the preparation's activity, no receptor interaction has been characterised, and no conventional pharmacokinetic profile can be defined for a mixture whose components differ in size, charge and stability.

Preclinical work has reported effects consistent with the hypothesis without identifying what produces them. In a rat stroke model, administration reduced infarct size and improved motor and cognitive performance, and hippocampal AMPA-GRIA1 subunit levels rose while NMDA-R1 levels did not ^[12]. In a rodent closed-head trauma model, functional scores improved ^[13]. Those are effects observed after administering the whole mixture.

This matters for how the clinical literature should be read. Where a defined molecule fails in a trial, the failure can be traced to a mechanism, a concentration, or a population. Where a mixture fails, none of that diagnosis is available — and where it succeeds, the result cannot be attributed to anything in particular, or reproduced by another manufacturer.

Preclinical Research on Cerebrolysin

Animal research

No in vitro characterisation of an isolated active constituent exists. The mechanistic evidence is animal work on the whole preparation.

Rat model of stroke with environmental enrichment. Stroke was induced in 40 male rats, with administration beginning 24 hours later at 2.5 mL/kg, alone or combined with an enriched environment, for 10 days. Motor function was assessed by the Bederson test and cognition by novel object recognition; infarct size was measured by histology and hippocampal receptor subunits by ELISA. Motor and cognitive performance improved with the preparation and with enrichment, infarct size fell in all treated groups, AMPA-GRIA1 rose only in the combined experimental group, and NMDA-R1 did not differ ^[12]. The selective change in one glutamate receptor subunit and not the other is the most specific mechanistic observation on this page, and it comes from a group with no connection to the manufacturer.

Experimental closed head trauma in rodents. Administration after experimental closed head trauma was reported to improve functional outcome ^[13].

Two limits apply to both. Rodent stroke and trauma models have a long record of producing neuroprotection results that do not survive translation — that is the general history of the field, not a criticism of these studies in particular. And in each case the intervention was the entire mixture, so the experiments cannot say what in it was responsible.

Findings described in this section were observed in rats. Nothing in them establishes anything about humans.

What Is Cerebrolysin Being Researched For?

• Acute ischaemic stroke — the largest body of work, including the 1,070-participant CASTA trial ^{[3, 4]} and seven randomised trials pooled in the current Cochrane review ^[1].
• Rehabilitation after stroke — the CARS trial examined motor function of the upper limb at day 90 alongside a standardised rehabilitation programme ^[5], and later work has examined aphasia and adjunctive use with mechanical thrombectomy.
• Moderate-to-severe head trauma — the CAPTAIN trial series and its prospective meta-analysis ^{[6, 7, 8]}.
• Vascular dementia — six randomised trials pooled in the 2019 Cochrane review ^[2].
• Alzheimer's disease and mild cognitive impairment — reviewed at length by authors describing three decades of clinical use ^[11] and assessed within an overview of systematic reviews of Alzheimer's pharmacotherapy ^[10].

Each of those is research into a registered pharmaceutical preparation, administered under protocol by clinicians to defined patient populations. None of it is research into, or evidence about, research-grade material supplied for laboratory use.

Human Research on Cerebrolysin

Human clinical research

Results from pharmaceutical clinical trials describe the investigational material and populations used in those studies and should not be interpreted as establishing the effects of research-grade materials offered for laboratory use.

CASTA — acute ischaemic stroke, 2012

Population. 1,070 participants with acute ischaemic hemispheric stroke, randomised within 12 hours of symptom onset; 529 to the active arm and 541 to placebo, across sites in Asia ^{[3, 4]}.

Endpoint and duration. 30 mL daily by intravenous infusion for 10 days alongside aspirin 100 mg daily, against saline; follow-up to 90 days. The primary endpoint was a combined global directional test of the modified Rankin Scale, the Barthel Index and the NIH Stroke Scale ^[3].

Result. The confirmatory endpoint showed no significant difference between groups. A post hoc analysis stratified by severity showed a trend favouring the active arm among participants with NIH Stroke Scale above 12 — odds ratios of 1.27 on both the NIH Stroke Scale and the modified Rankin Scale, with confidence-interval lower bounds of 0.97 and 0.90. In that subgroup, cumulative 90-day mortality was 10.5% in the active arm against 20.2% on placebo ^[3].

Limitations. The trial was neutral on the endpoint it was designed to test. The severity subgroup finding is post hoc, and its confidence intervals cross unity on the two functional scales; the authors state that the observation should be confirmed by a further clinical trial, which is the appropriate weight to give it.

CARS — motor function in early rehabilitation, 2016

Population and design. A prospective, randomised, double-blind, placebo-controlled, multicentre, parallel-group study in people after stroke. 30 mL daily or saline for 21 days, beginning 24 to 72 hours after stroke onset, with all participants in a standardised 21-day rehabilitation programme. Primary endpoint the Action Research Arm Test score at day 90 ^[5].

Result. The nonparametric effect size on the Action Research Arm Test at day 90 indicated a large superiority over placebo; a multivariate effect size across 12 outcome scales indicated small-to-medium superiority. Premature discontinuation was under 5%, and tolerability was reported as comparable to placebo ^[5].

Limitations. The authors describe the study as exploratory with a relatively small sample size and state that the results should be confirmed in a large-scale randomised trial. That confirmation has not been published.

CAPTAIN I and II — moderate-to-severe head trauma, 2020

Design. Two randomised, placebo-controlled, double-blind trials in people after moderate-to-severe traumatic brain injury as an adjunct to standard care. CAPTAIN II was a single-centre phase IIIb/IV trial enrolling participants with a Glasgow Coma Score between 7 and 12, given 50 mL daily for 10 days followed by two further 10-day cycles of 10 mL daily, against saline ^{[6, 7]}.

Result. CAPTAIN II enrolled 142 participants, 139 of whom entered formal analysis, with mean age 47.4 and mean admission Glasgow Coma Score 10.4. The primary endpoint, a multidimensional ensemble of 13 outcome scales, showed a small-to-medium effect favouring the active arm, statistically significant at day 90 (MW combined 0.59, 95% CI 0.52 to 0.66, p = 0.0119). Safety and tolerability were comparable between groups ^[7]. A prospective meta-analysis of the trial series pooled the programme ^[8].

Limitations. 139 analysed participants at a single centre; a primary endpoint constructed from 13 scales combined into one multivariate test, which is a legitimate and prespecified approach and also a less transparent one than a single named outcome; and an effect the authors themselves grade as small-to-medium.

The Cochrane assessments

Acute ischaemic stroke, seventh update, 2023. Seven randomised trials, 1,773 participants, including one trial of a related preparation. Moderate-certainty evidence that the preparation probably results in little to no difference in all-cause death (risk ratio 0.96). Moderate-certainty evidence of little to no difference in the total number of people with serious adverse events (RR 1.16, 95% CI 0.81 to 1.66; 3 trials, 1,335 participants), comprising fatal events (RR 0.90, 95% CI 0.59 to 1.38) and an increase in non-fatal serious adverse events (RR 2.39, 95% CI 1.10 to 5.23). In the subgroup receiving 30 mL daily for 10 days — a cumulative 300 mL — that increase was more prominent (RR 2.87, 95% CI 1.24 to 6.69; 2 trials, 1,189 participants). None of the included studies reported poor functional outcome defined as death or dependence, early death, or quality of life. The review authors record that the manufacturer supported three of the multicentre studies ^[1].

Vascular dementia, 2019. Six randomised trials, 597 participants, follow-up from 15 days to three years. Pooling cognitive scores from three studies in 420 people gave a standardised mean difference of 0.36 (95% CI 0.13 to 0.58) favouring the preparation; global function response rates in two studies of 379 participants gave a risk ratio of 2.69 (95% CI 1.82 to 3.98). Both were rated very low quality. Adverse-event rates did not differ. Where funding was disclosed, all studies were supported by the pharmaceutical industry. The review authors state that the analyses were limited by heterogeneity, that the included papers had high risk of bias, and that if benefits exist the effects may be too small to be clinically meaningful ^[2].

Safety specifically. A separate systematic review and meta-analysis of twelve randomised controlled trials examined the safety record in acute ischaemic stroke ^[9].

Dementia of Alzheimer type

An overview of systematic reviews of Alzheimer's pharmacotherapy grouped this preparation with several other agents that appear to improve cognitive function in that population while describing the evidence for them as limited ^[10]. A 2021 review covering three decades of clinical use sets out the case in more detail ^[11]; it should be read with an eye to the authorship and sponsorship conventions of this literature, which the Cochrane reviews document ^[2].

How to hold these together

The trials and the reviews are not in factual conflict. They differ on what counts. Trials in this programme have generally used multidimensional outcome ensembles — defensible for conditions with diffuse deficits, and more permissive than a single hard endpoint. The reviews restrict themselves to prespecified hard outcomes, apply GRADE, and downgrade for unclear allocation concealment, unclear selective outcome reporting and industry sponsorship. A reader who wants one number from this page will not find one; what the literature supports is that the preparation is well tolerated on aggregate measures, that no mortality benefit has been demonstrated in ischaemic stroke, that a non-fatal serious adverse event signal exists at the higher cumulative volume, and that the functional and cognitive findings rest on evidence its own systematic reviewers grade as low to very low certainty.

Current Research Status

Status as of September 22, 2026. This block is rendered from maintained fields, not from prose, so it cannot go stale in one place and stay current in another.

Cerebrolysin vs Related Compounds

Against defined synthetic peptides

Semax, Selank and Pinealon are single molecules with sequences, formulae and identifiers. This preparation is a mixture with none of those. The difference is not one of degree: a finding about a defined peptide can in principle be reproduced anywhere from the structure, and a finding about this preparation can only be reproduced with material from the same process.

Against other brain-derived preparations

Cortexin is a comparable polypeptide preparation used in the same countries, and the current Cochrane review incorporated a trial of it as a Cerebrolysin-like agent ^[1]. Russian rodent work has compared the two directly ^[12]. They are different products from different processes and their evidence bases are not interchangeable.

Against thymic and pineal extracts

Thymalin is also an animal-tissue extract rather than a defined molecule, and shares the analytical problem described above. It does not share a research programme, a target organ or an evidence base with this preparation.

Evidentiary position

Among the compounds in this library, this one has by a wide margin the most randomised human data and the most systematic-review scrutiny. More data has produced a sharper picture, not a more favourable one, which is what the review process is for.

No comparison of effect between these compounds is made on this page.

Chemical & Molecular Characteristics

This section exists on every entry in the library to record structure. Here it records the absence of one, and what follows from that.

There is no molecule to characterise. The preparation is an aqueous solution of low-molecular-weight peptides and free amino acids from enzymatically digested porcine brain protein ^[1]. Registers reflect this: the FDA/NCATS Global Substance Registration System classifies it as structurally diverse under UNII 37KZM6S21G with CAS registry number 12656-61-0, and PubChem — which indexes defined structures — has no record for it.

Identity is defined by process. For a defined peptide, two lots from two manufacturers with the same sequence and the same purity are the same substance. Here, identity rests on the source tissue, the enzymes, the digestion conditions and the fractionation. A preparation made by a different process from the same tissue is a different substance, however similar its description, and that is why the Cochrane reviewers treat Cerebrolysin-like agents as a category requiring separate consideration rather than as the same intervention ^[1].

Quantification is by volume. Trial protocols specify millilitres of solution daily — 30 mL in the stroke trials, 50 mL in the early phase of CAPTAIN II ^{[3, 5, 7]}. There is no milligram figure for an active substance because there is no identified active substance. The Cochrane subgroup finding on non-fatal serious adverse events is stated in terms of a cumulative volume of 300 mL for the same reason ^[1].

The source is animal tissue. Material derived from porcine central nervous system carries a different regulatory and quality framework from a synthetic peptide, covering the source herd, viral safety and transmissible agent risk. Those controls belong to the licensed pharmaceutical product in the jurisdictions where it is registered, and nothing about them transfers to material offered elsewhere under the same name.

No analytical purity figure is meaningful. A percentage purity presupposes a single intended species and a set of impurities. For a mixture that is by design heterogeneous, a purity number on a certificate describes nothing determinate, and mass spectrometry confirms the presence of many species rather than the identity of one.

Frequently Asked Questions

Scientific References

1. Ziganshina LE, Abakumova T, Nurkhametova D, et al.. Cerebrolysin for acute ischaemic stroke The Cochrane database of systematic reviews; 2023. PMID 37818733 doi:10.1002/14651858.CD007026.pub7
2. Cui S, Chen N, Yang M, et al.. Cerebrolysin for vascular dementia The Cochrane database of systematic reviews; 2019. PMID 31710397 doi:10.1002/14651858.CD008900.pub3
3. Heiss WD, Brainin M, Bornstein NM, et al.. Cerebrolysin in patients with acute ischemic stroke in Asia: results of a double-blind, placebo-controlled randomized trial Stroke; 2012. PMID 22282884
4. The Safety and Efficacy of Cerebrolysin in Patients With Acute Ischemic Stroke 2006. NCT00868283
5. Muresanu DF, Heiss WD, Hoemberg V, et al.. Cerebrolysin and Recovery After Stroke (CARS): A Randomized, Placebo-Controlled, Double-Blind, Multicenter Trial Stroke; 2016. PMID 26564102
6. Poon W, Matula C, Vos PE, et al.. Safety and efficacy of Cerebrolysin in acute brain injury and neurorecovery: CAPTAIN I-a randomized, placebo-controlled, double-blind, Asian-Pacific trial Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology; 2020. PMID 31494820 doi:10.1007/s10072-019-04053-5
7. Muresanu DF, Florian S, Hömberg V, et al.. Efficacy and safety of cerebrolysin in neurorecovery after moderate-severe traumatic brain injury: results from the CAPTAIN II trial Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology; 2020. PMID 31897941 doi:10.1007/s10072-019-04181-y
8. Vester JC, Buzoianu AD, Florian SI, et al.. Cerebrolysin after moderate to severe traumatic brain injury: prospective meta-analysis of the CAPTAIN trial series Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology; 2021. PMID 33620612 doi:10.1007/s10072-020-04974-6
9. Strilciuc S, Vécsei L, Boering D, et al.. Safety of Cerebrolysin for Neurorecovery after Acute Ischemic Stroke: A Systematic Review and Meta-Analysis of Twelve Randomized-Controlled Trials Pharmaceuticals (Basel, Switzerland); 2021. PMID 34959697 doi:10.3390/ph14121297
10. Majidazar R, Rezazadeh-Gavgani E, Sadigh-Eteghad S, et al.. Pharmacotherapy of Alzheimer's disease: an overview of systematic reviews European journal of clinical pharmacology; 2022. PMID 35881170 doi:10.1007/s00228-022-03363-6
11. Gavrilova SI, Alvarez A. Cerebrolysin in the therapy of mild cognitive impairment and dementia due to Alzheimer's disease: 30 years of clinical use Medicinal research reviews; 2021. PMID 32808294 doi:10.1002/med.21722
12. Martínez-Torres NI, Cárdenas-Bedoya J, Vázquez-Torres BM, et al.. Environmental enrichment and cerebrolysin improve motor and cognitive performance in a rat model of stroke, in conjunction with an increase in hippocampal AMPA but not NMDA receptor subunits Brain research; 2024. PMID 38048977 doi:10.1016/j.brainres.2023.148694
13. Zhang Y, Chopp M, Meng Y, et al.. Improvement in functional recovery with administration of Cerebrolysin after experimental closed head injury Journal of neurosurgery; 2013. PMID 23581594 doi:10.3171/2013.3.JNS122061

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Research-Use Information

For in vitro research use only. This material is a laboratory reagent. It is not a drug, food, dietary supplement, or cosmetic and is not for human or veterinary use, including ingestion, injection, or any other administration. No information on this page describes or implies any effect in humans or animals. Sold only to researchers under our Terms of Sale.