What it is
Cerebrolysin is unusual in this library because it is not a molecule. It is a mixture.
Porcine brain proteins — pig brain — are broken down by enzymes in a standardised process. What results is roughly 80% low-molecular-weight peptides and 20% free amino acids. That preparation is what is sold and injected.
This matters more than it might sound. Every other entry here has a sequence that can be written out and checked — what that sequence means is the first thing to understand about any of them. This one has a manufacturing process instead.
Where it is a medicine and where it is not
Cerebrolysin is licensed and widely prescribed in Russia, Eastern Europe, China and a number of other Asian and post-Soviet countries, for stroke, traumatic brain injury and dementia. It shares that geography with Semax, and the pattern recurs across the compounds sold for focus and mood. In the United States it is not approved for anything.
Both facts are true at once, and writing about the compound tends to lean on whichever one suits. "An approved medicine" and "an unapproved research chemical" are both defensible descriptions depending on which border you are standing at.
What the independent evidence found
This compound has something most entries here lack: a Cochrane systematic review, which is an independent assessment of all the trials rather than any single one.
For acute ischaemic stroke, that review pooled seven randomised trials with 1,773 participants. Its conclusion, at moderate certainty, was that Cerebrolysin probably has no beneficial effect on preventing death from any cause, and probably no beneficial effect on the number of people experiencing serious adverse events. It also reported a potential increase in non-fatal serious adverse events.
A separate Cochrane review of vascular dementia found inconsistent results.
Why individual studies read better than the review
The review authors were specific about the limitations, and they are worth repeating because they explain the gap.
Three of the seven trials were supported by the manufacturer, EVER Neuro Pharma GmbH, which supplied the drug, the placebo, the randomisation codes and the statisticians. Most trials had unclear or high risk of bias across several domains. Four lost between 16% and 29% of their participants. Four had no publicly available protocol, and three registered a protocol only after the fact.
None of that proves any individual result wrong. It does mean the evidence is weaker than the volume of published papers suggests, and it is why a pooled independent review reaches a flatter conclusion than the trials read one at a time.
The authors added that their conclusions are likely to change if further studies become available. That is an honest position, and it is where this compound sits.
Last checked
2026-09-07.