CerebrolysinWhat the studies show

Q: What kind of evidence exists for cerebrolysin?

Large human trials. Randomised placebo-controlled trials in people, including one with over a thousand patients, with a missed primary endpoint in acute stroke, low-quality signals in dementia, and a Cochrane review that found no effect on death or disability.

A peptide mixture extracted from pig brains, approved in Austria and Russia, that missed its primary endpoint in a 1,070-patient stroke trial.

5 min read · Large human trials · Updated November 2026

In short

Name: cerebrolysin
Evidence: Large human trials
Bottom line: Randomised placebo-controlled trials in people, including one with over a thousand patients, with a missed primary endpoint in acute stroke, low-quality signals in dementia, and a Cochrane review that found no effect on death or disability.

Before you read this

This guide explains what published studies found. That is all it is.

It is not medical advice and it is not instructions for using anything. Where a dose appears, we are reporting what a named study gave the people or animals in it — a fact about the study, not an instruction to you.

The compounds here are not approved by the FDA for use in people and are sold for laboratory research only. A study tells you what happened to the subjects in it; it does not tell you what would happen to you. Talk to a doctor first.

What it is

Cerebrolysin is not a single peptide. It is a mixture made by enzymatically digesting purified pig brain protein into free amino acids and short peptides, standardised by its manufacturer, EVER Neuro Pharma in Austria, and given by injection or intravenous infusion. The idea behind it, which goes back decades, is that the mixture contains fragments that act like the brain's own growth factors. Cerebrolysin is an approved medicine in Austria and in a number of other countries including Russia, China and South Korea, for stroke, dementia and brain injury; it has no approval from the U.S. FDA or the European Medicines Agency ¹. Because it is a mixture, its active components have never been defined, which is one reason Western regulators have not taken it up and one reason the trials are hard to interpret.

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Stroke: the CASTA and CARS trials

The largest trial is CASTA, published in Stroke in 2012. It enrolled 1,070 people in Asia within 12 hours of an acute ischaemic stroke and gave them either 30 mL of cerebrolysin by daily infusion for ten days, or placebo, on top of standard care. At 90 days there was no difference between the groups on the combined measure of neurological function and disability that was the trial's primary endpoint ². A later analysis suggested that the subgroup with the most severe strokes might have done better on cerebrolysin, but that was not what the trial was designed to test, and subgroup findings after a negative primary result are where false positives live.

A smaller trial, CARS, published in 2016, asked a different question. It gave 208 people who had recently had a stroke either cerebrolysin or placebo alongside rehabilitation for three weeks, with arm function at 90 days as the primary outcome; the cerebrolysin group scored higher on the Action Research Arm Test ³. The 2023 Cochrane review of all randomised trials in acute ischaemic stroke, which pooled seven trials, found no evidence of benefit on death or on disability, and a higher rate of non-fatal serious adverse events in the cerebrolysin groups ¹.

Dementia

A Cochrane review of cerebrolysin for vascular dementia, updated in 2019, pooled the randomised trials and found that patients on cerebrolysin did somewhat better than those on placebo on cognitive tests and on clinicians' overall ratings, but graded the evidence as low quality: the trials were small, short, and several had problems with how they were run and reported ⁴. In Alzheimer's disease, a 2015 meta-analysis of six trials, with authors from the manufacturer among its contributors, reached a similar place: a measurable difference on global clinical ratings, a weaker one on cognition, and trials too short and too few to settle the question ⁵.

What is not known

The central problem is that cerebrolysin is a mixture, so there is no single molecule whose dose, half-life and target can be measured, and the proposed mechanism of growth-factor-like peptides has never been pinned to specific components. The best stroke trial missed its primary endpoint, and the Cochrane stroke review points toward more serious adverse events rather than benefit. The dementia signal is consistent across small trials but rests on weak ones. Most of the trials were funded or co-authored by the manufacturer. After thirty years of clinical use in several countries, the honest summary is that cerebrolysin has been tested properly, and the tests mostly did not show what its supporters expected.

What these studies are, and aren't

Large human trials. Randomised placebo-controlled trials in people, including one with over a thousand patients, with a missed primary endpoint in acute stroke, low-quality signals in dementia, and a Cochrane review that found no effect on death or disability.