Sleep, Energy & Cognition
Cerebrolysin: What Has Actually Been Trialled?
The short answer
A registry search this session found 42 trials of Cerebrolysin — a porcine-brain-derived peptide mixture — spanning stroke, vascular dementia, Alzheimer's disease, traumatic brain injury, Down syndrome, Bell's palsy, CADASIL, COVID-19-related smell loss, ICU delirium prevention, and even hair repigmentation. The largest single trial, a 1,070-patient acute ischemic stroke study called CASTA, found no significant difference from placebo on its primary combined endpoint, though a post-hoc subgroup of the most severely affected patients showed a mortality trend favoring Cerebrolysin. A 2013 Cochrane review of 597 vascular dementia patients across six trials found modest cognitive improvement over placebo but concluded there was still insufficient evidence to recommend routine use. Many of the trials in the registry are sponsored by Ever Neuro Pharma GmbH, the drug's manufacturer.
Quick answers
- What is it?
- What Cerebrolysin, a porcine-brain-derived peptide mixture, has actually been tested for in clinical trials and whether those trials found a benefit.
- Why are people interested in it?
- Cerebrolysin is marketed for brain and memory conditions, so people want to know if the trials actually back that up.
- What has actually been studied?
- A registry search finding 42 trials across stroke, dementia, Alzheimer's, and traumatic brain injury; the largest was a 1,070-patient stroke trial (CASTA), plus a Cochrane review of 597 vascular dementia patients and a 123-patient post-stroke aphasia trial.
- How strong is the evidence?
- Mixed — the largest trial (CASTA) found no significant benefit on its primary endpoint, while smaller pooled reviews found modest positive signals, and many trials are sponsored by the drug's manufacturer.
- What don't we know yet?
- Whether results replicate independently outside the manufacturer's trial network, whether a large dedicated trial would confirm benefit in Alzheimer's disease specifically, and long-term outcomes beyond about 90 days.
- Where can I read the original research?
- Sources at the bottom of this page: Cerebrolysin in patients with acute ischemic stroke in Asia: results of a double-blind, placebo-controlled randomized trial and A double-blind, placebo-controlled, randomized trial to evaluate the safety and efficacy of Cerebrolysin in patients with acute ischaemic stroke in Asia--CASTA.
The short answer: A registry search this session found 42 trials of Cerebrolysin — a porcine-brain-derived peptide mixture — spanning stroke, vascular dementia, Alzheimer's disease, traumatic brain injury, Down syndrome, Bell's palsy, CADASIL, COVID-19-related smell loss, ICU delirium prevention, and even hair repigmentation. The largest single trial, a 1,070-patient acute ischemic stroke study called CASTA, found no significant difference from placebo on its primary combined endpoint, though a post-hoc subgroup of the most severely affected patients showed a mortality trend favoring Cerebrolysin. A 2013 Cochrane review of 597 vascular dementia patients across six trials found modest cognitive improvement over placebo but concluded there was still insufficient evidence to recommend routine use. Many of the trials in the registry are sponsored by Ever Neuro Pharma GmbH, the drug's manufacturer.
What the research shows
What Cerebrolysin is, and the breadth of what it's been tested on
Cerebrolysin is a mixture of peptides and amino acids derived from porcine (pig) brain tissue, given by injection or infusion, and marketed in some countries as having neurotrophic and neuroprotective properties — claims originally supported by animal-model studies of cerebral ischemia rather than human data. A ClinicalTrials.gov search conducted this session returned 42 registered trials of Cerebrolysin, both interventional and observational. The range of conditions tested is unusually broad for a single compound: acute ischemic and hemorrhagic stroke, vascular dementia, Alzheimer's disease, traumatic brain injury (in adults and children with cerebral palsy), Down syndrome, subarachnoid hemorrhage, CADASIL (a rare genetic small-vessel brain disease), neonatal hypoxic-ischemic encephalopathy, Bell's palsy, post-stroke aphasia, disorders of consciousness, ICU and postoperative delirium prevention, post-COVID-19 smell and taste loss, and — in one five-participant pilot — hair repigmentation in patients already on Cerebrolysin for a neurological condition. Most trials are small; enrollment across the 30 with reported figures ranged from 5 to 1,851 participants, and a large share were sponsored by Ever Neuro Pharma GmbH, the drug's manufacturer.
The largest trial: a neutral primary result, with a subgroup hint
The single largest and most rigorously designed trial is CASTA (Cerebrolysin in Asian Stroke Trial), a multicenter, double-blind, placebo-controlled study registered as NCT00868283. Its 2009 published protocol described plans to enroll around 1,060 patients with acute ischemic hemispheric stroke across more than 50 centers, treated with 30 mL of Cerebrolysin or saline placebo daily for 10 days on top of standard aspirin therapy. The results, published in Stroke in 2012, enrolled 1,070 patients (529 Cerebrolysin, 541 placebo) and followed them for 90 days. The confirmatory primary endpoint — a combined directional test of the modified Rankin Scale, Barthel Index, and NIH Stroke Scale — showed no significant difference between groups. A post-hoc subgroup analysis of the more severely affected patients (NIH Stroke Scale score above 12) showed a trend favoring Cerebrolysin on functional outcome and mortality, with 90-day mortality of 20.2% on placebo versus 10.5% on Cerebrolysin — a finding the authors flagged as needing confirmation in a follow-up trial that does not appear to have been completed.
Where the pooled evidence looks modestly more favorable
Two systematic reviews found small-to-moderate positive signals when trials were pooled, with caveats attached to both. A 2013 Cochrane review identified six randomized controlled trials of Cerebrolysin for vascular dementia, totaling 597 participants. Pooled results favored Cerebrolysin on general cognitive function, measured by the Mini-Mental State Examination (weighted mean difference 1.10 points, 95% CI 0.37-1.82) and the Alzheimer's Disease Assessment Scale-Cognitive Subscale (weighted mean difference -4.01 points, meaning less impairment), and on global clinical response rate (relative risk 2.71). Despite those numbers, the Cochrane authors concluded there was "insufficient evidence to recommend Cerebrolysin as a routine treatment for vascular dementia," citing the limited number of trials and short follow-up in most of them. A larger, more recent 2025 meta-analysis in Alzheimer's & Dementia, covering 173 trials and 22,347 participants across all vascular cognitive impairment interventions, placed Cerebrolysin among several agents showing "small to moderate improvements in cognition" — smaller than the effect the same review found for Ginkgo biloba extract, and framed against a backdrop the authors described as having "substantial heterogeneity" and few interventions "reproducibly tested in adequately sized and designed studies."
The most positive single result, and its limits
The most favorable individual result identified this session comes from a narrower application: post-stroke language recovery. The ESCAS trial, published in Stroke in 2025, randomized 123 patients with nonfluent aphasia after acute ischemic stroke to Cerebrolysin plus speech therapy, or placebo plus the same therapy, across two Romanian stroke centers. By 90 days, the Cerebrolysin group improved 35.6 points on the Western Aphasia Battery language score versus 20.8 points on placebo — a between-group difference of 14.8 points (95% CI 9.5-20.1, p<0.001) — alongside a significantly larger drop in NIH Stroke Scale score. This is a genuinely positive, statistically clear result. It is also a single pilot-scale trial at two centers, in one specific post-stroke condition, not yet replicated independently at larger scale.
What we don't know yet
Whether results replicate independently, outside the manufacturer's own trial network. A substantial share of the registered trials retrieved this session are sponsored by the company that makes the drug, which does not invalidate the findings but does limit how much independent confirmation currently exists.
Whether a large, dedicated trial would confirm benefit specifically in Alzheimer's disease. The umbrella review that grouped Cerebrolysin with acetylcholinesterase inhibitors and Ginkgo biloba as "beneficial" drew on smaller pooled studies, not one definitive large RCT comparable in scale to CASTA.
The outcome of the completed COVID-19 smell-and-taste-loss trials. Two trials in this indication (250 and 160 participants) are listed as completed on the registry, but published results were not identified in this session's search.
Long-term outcomes beyond roughly 90 days, which is the follow-up window for most of the trials described here, including CASTA and ESCAS.
Why a single compound has been tested across such an unusually wide range of unrelated conditions — from stroke to hair repigmentation — without, in most cases, a large confirmatory trial in any single one of them.
Sources
- Heiss WD, Brainin M, Bornstein NM, Tuomilehto J, Hong Z. Cerebrolysin in patients with acute ischemic stroke in Asia: results of a double-blind, placebo-controlled randomized trial. Stroke, 2012;43(3):630-636. DOI
- Hong Z, Moessler H, Bornstein N, Brainin M, Heiss WD. A double-blind, placebo-controlled, randomized trial to evaluate the safety and efficacy of Cerebrolysin in patients with acute ischaemic stroke in Asia--CASTA. International Journal of Stroke, 2009;4(5):406-412. DOI
- Chen N, Yang M, Guo J, Zhou M, Zhu C, He L. Cerebrolysin for vascular dementia. Cochrane Database of Systematic Reviews, 2013;(1):CD008900. DOI
- Fan F, Liu H, Shi X, Ai Y, Liu Q, Cheng Y. The Efficacy and Safety of Alzheimer's Disease Therapies: An Updated Umbrella Review. Journal of Alzheimer's Disease, 2022;85(3):1195-1204. DOI
- Masserini F, Gendarini C, Baso G, Salvadori E, Pantoni L. Therapeutic strategies in vascular cognitive impairment: A systematic review and meta-analysis. Alzheimer's & Dementia, 2025;21(11):e70840. DOI
- Homberg V, Jianu DC, Stan A, et al. Speech Therapy Combined With Cerebrolysin in Enhancing Nonfluent Aphasia Recovery After Acute Ischemic Stroke: ESCAS Randomized Pilot Study. Stroke, 2025;56(4):937-947. DOI
- ClinicalTrials.gov. Registry search for interventional and observational trials of Cerebrolysin, retrieved 2026.
Article records maintained via PubMed. Peptide Proof reports what studies found. It does not provide medical advice, dosing guidance, or treatment recommendations.
Topic: Brain & Cognitive Health | Evidence Index: cerebrolysin
Sources
- Cerebrolysin in patients with acute ischemic stroke in Asia: results of a double-blind, placebo-controlled randomized trial
- Stroke, 2012 · n=1070 · DOI
- A double-blind, placebo-controlled, randomized trial to evaluate the safety and efficacy of Cerebrolysin in patients with acute ischaemic stroke in Asia--CASTA
- International Journal of Stroke, 2009 · DOI
- Cerebrolysin for vascular dementia
- Cochrane Database of Systematic Reviews, 2013 · n=597 · DOI
- The Efficacy and Safety of Alzheimer's Disease Therapies: An Updated Umbrella Review
- Journal of Alzheimer's Disease, 2022 · DOI
- Therapeutic strategies in vascular cognitive impairment: A systematic review and meta-analysis
- Alzheimer's & Dementia, 2025 · n=22347 · DOI
- Speech Therapy Combined With Cerebrolysin in Enhancing Nonfluent Aphasia Recovery After Acute Ischemic Stroke: ESCAS Randomized Pilot Study
- Stroke, 2025 · n=123 · DOI
- ClinicalTrials.gov registry search for interventional and observational trials of Cerebrolysin
- ClinicalTrials.gov, 2026
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