Evidence Files
Cerebrolysin: The Austrian Brain Drug That Austria Doesn't Use
The largest trial of Cerebrolysin in stroke enrolled 1,070 patients and found no difference from saline on its primary endpoint. Cochrane's 2023 review goes further: no benefit for survival, and — with moderate certainty — a probable increase in serious non-fatal adverse events. This is not a drug nobody studied. It is a drug that was studied carefully, with an inconvenient result.
Verdict
TRICK (weak evidence)
We searched PubMed and Cochrane Library for cerebrolysin evidence. There is plenty of it: 673 publications and 63 randomised controlled trials. The question is what they found. For acute ischaemic stroke, Cochrane's 2023 review concludes with moderate certainty that cerebrolysin probably has no beneficial effect on preventing death — and, again with moderate certainty, that it probably increases serious non-fatal adverse events. For vascular dementia, a separate Cochrane review did find improvement in cognition, but called the evidence base weak and noted that any benefit may be too small to be clinically meaningful.
Why it's everywhere except where it's made
Cerebrolysin is a mixture of peptides and amino acids derived from pig brain tissue, manufactured by EVER Neuro Pharma in Austria. The theory behind it: neuropeptides from mammalian brain tissue cross the blood-brain barrier and exert neuroprotective and neurotrophic effects — promoting neuron survival and repair.
The product was developed in the Soviet scientific tradition of biological medicines, where extracts of animal origin were viewed as pharmacologically potent. It found its market in the post-Soviet world and spread to China, which now runs a significant share of clinical trials on it.
The EU regulatory environment requires substantial clinical evidence for prescription medicines — which is why cerebrolysin isn't in Austrian or German stroke protocols. The countries where it's most prescribed have different, generally lower evidence thresholds for drug approval. The gap is not for lack of testing: the largest trial enrolled over a thousand patients and Cochrane has reviewed the drug repeatedly. The results simply weren't the ones a prescription implies.
What the science actually says
Cerebrolysin is the rare case where "nobody studied it" doesn't apply. It was studied thoroughly — which is precisely why the conclusion is so awkward.
- The largest trial found nothing. CASTA (1,070 patients, *Stroke*, 2012) compared a ten-day course against saline in acute ischaemic stroke. The primary endpoint showed no significant difference between groups. A positive signal appeared only in a post hoc subgroup with more severe strokes — which counts as a hypothesis, not a finding
- Cochrane on stroke: no survival benefit. The 2023 review concludes with moderate certainty that cerebrolysin probably does not reduce all-cause death after acute ischaemic stroke
- And probably causes more serious adverse events. The same review, again at moderate certainty, indicates a potential increase in non-fatal serious adverse events. This is what makes "might as well try it, can't hurt" the wrong frame here
- Cochrane on dementia: an effect, but a weak evidence base. The 2019 review did find improved cognition and general function in vascular dementia — while stating plainly that the data are not definitive, the included trials carried high risk of bias, and any benefit may be too small to be clinically meaningful
- No new dementia trials have appeared. The reviewers noted that no new studies had been published since their previous version, even as the drug continued to be promoted for that indication
- WHO and FDA — not on the WHO essential medicines list; not approved by the FDA for any indication
Why the answer differs for stroke and for dementia
Acute ischaemic stroke
The evidence here is the most complete and the least favourable: the largest trial was negative, Cochrane finds no survival benefit and flags a probable rise in serious adverse events. This is also the indication cerebrolysin is most often prescribed for.
Vascular dementia
Here Cochrane did find improvement in cognitive scores — but with high risk of bias in the included trials and an explicit warning that the effect may not be clinically meaningful. That is "possibly something, poorly demonstrated", not established efficacy.
Frequently asked questions
+Does Cerebrolysin help recovery after a stroke?
The largest trial says no. CASTA, with 1,070 patients, found no significant difference from placebo on its primary endpoint, and Cochrane's 2023 review adds that it probably has no effect on mortality. Improvement after a course of infusions is mostly explained by natural recovery and rehabilitation, both of which happen regardless.
+Can Cerebrolysin do harm?
Cochrane's 2023 review indicates, at moderate certainty, a potential increase in serious non-fatal adverse events among patients given cerebrolysin. That is the specific reason the common argument — it might help and it can't hurt — doesn't hold here. On the available evidence, it can.
+It's a natural peptide preparation from brain tissue — isn't that safer than synthetic drugs?
Origin says nothing about either safety or efficacy. Cerebrolysin is a mixture of peptides derived from pig brain tissue; that makes it neither automatically gentle nor automatically useful. It is judged the same way as anything else: by what controlled trials in humans showed.
+Why is it prescribed so widely if the evidence is this weak?
Largely inertia, plus the pull of doing something visible after a stroke. A course of infusions looks like treatment; "early rehabilitation and blood pressure control" looks like doing nothing, even though it is the part with the evidence. The drug also entered post-Soviet protocols long before the large independent trials existed, and prescribing habits outlived the evidence beneath them.
+What actually helps recovery after a stroke?
What the international guidelines contain: rehabilitation started as early as possible, work with physiotherapists and speech therapists, control of blood pressure, glucose and lipids, antithrombotic therapy as prescribed, and stopping smoking. Less dramatic than a drip, but this is where the measurable effect is.
Our Conclusion
Cerebrolysin is not a case of "nobody ever looked". People looked carefully, and that is exactly why the answer is so uncomfortable: the largest trial, with 1,070 patients, found no difference from saline, and Cochrane's 2023 review found no survival benefit in stroke while flagging a probable increase in serious adverse events. Vascular dementia is the one place the picture differs — an effect was found there, but the reviewers themselves called the evidence weak and suggested the benefit may be too small to matter clinically. The practical consequence is straightforward: the familiar argument that it might help and certainly can't hurt does not survive contact with the data, because on the available evidence it can hurt. If cerebrolysin has been prescribed to you or a family member after a stroke, the question worth asking is specific: what will this course change in my case, and would that effort and money do more in early rehabilitation?
Sources
Every claim in this article rests on a primary publication. Links go to the publisher's site or to PubMed, the US National Library of Medicine database.
- Ziganshina L.E., Abakumova T., Nurkhametova D., Ivanchenko K. Cerebrolysin for acute ischaemic stroke. Cochrane Database of Systematic Reviews, 2023.
- Cui S., Chen N., Yang M. et al. Cerebrolysin for vascular dementia. Cochrane Database of Systematic Reviews, 2019.
- Heiss W.D., Brainin M., Bornstein N.M., Tuomilehto J., Hong Z. Cerebrolysin in patients with acute ischemic stroke in Asia: results of a double-blind, placebo-controlled randomized trial (CASTA). Stroke, 2012.
This article is for informational purposes only and does not constitute medical advice. Trick or Treatment analyses the presence of clinical studies in open scientific databases — PubMed and Cochrane Library. The absence of studies in these databases does not automatically mean a drug is ineffective, but it does mean its effectiveness has not been confirmed by evidence-based medicine standards. Any treatment decisions should be made together with your doctor.