Cerebrolysin: the pig-brain peptide mixture licensed abroad, and what its trials actually show

Cerebrolysin is not a single peptide. It is a standardised preparation made by breaking down purified pig brain protein with enzymes, then filtering out everything above about 10,000 daltons. What remains is a solution of short peptides and free amino acids, of which the manufacturer states the peptide fraction contains fragments that act like nerve growth factors ^[1]. The Cochrane Collaboration describes it as a mixture of low-molecular-weight peptides and amino acids derived from porcine brain, widely used for acute ischaemic stroke in Russia, Eastern Europe, China and other Asian and post-Soviet countries ^[5].

It is manufactured in Austria and sold as a solution for injection at 215.2 mg of cerebrolysin concentrate per mL, with sodium hydroxide and water for injection as the only excipients ^[10][11]. The manufacturer’s stated indications are cerebrovascular disorders, including Alzheimer-type dementia, vascular dementia, stroke and craniocerebral trauma ^[10].

Research peptide stores sell cerebrolysin injection, often listed as a cerebrolysin peptide, alongside single peptides such as Semax, Selank, Dihexa and Cortagen, often imported from countries where it is licensed. That makes it unusual on PepFinder: it is a real prescription medicine in some countries, with a real trial record, sold without a licence in others. This guide sets out that trial record, and the cerebrolysin benefits it does and does not support, which is more mixed than sellers suggest.

The manufacturer and the researchers it funds describe cerebrolysin as a neurotrophic treatment: the peptide fraction is said to mimic the action of nerve growth factor, brain-derived neurotrophic factor and related molecules, protecting neurons from injury and promoting the growth of new connections. A 2012 review by Masliah and Díez-Tejedor sets out the proposed pharmacology, drawing on cell and animal studies in which cerebrolysin reduced neuron death after ischaemia, reduced amyloid pathology in transgenic mice and increased neurogenesis ^[1].

Two cautions apply. First, cerebrolysin is a mixture whose exact active components have not been isolated, so the mechanism is inferred from effects rather than from a defined molecule acting on a defined receptor. Second, the peptides in the preparation are small and given intravenously; how much of any specific fragment crosses the blood-brain barrier, and in what form, is not established in humans. The pharmacology review is a manufacturer-associated publication and should be read as such ^[1].

The largest trial is CASTA, published in Stroke in 2012. It randomised 1,070 patients with acute ischaemic stroke in Asia, within 12 hours of onset, to 30 mL of cerebrolysin or saline daily for ten days on top of aspirin. The confirmatory primary endpoint, a combined test of the modified Rankin Scale, Barthel Index and NIH Stroke Scale at 90 days, showed no significant difference between groups. A post hoc analysis suggested a trend in favour of cerebrolysin in the most severely affected patients (NIHSS above 12), with 90-day mortality of 10.5% against 20.2% in that subgroup, which the authors said needed confirming in a further trial ^[2].

The CARS trial took a different approach, treating patients 24 to 72 hours after stroke with 30 mL a day for 21 days alongside standardised rehabilitation, and measuring arm function on the Action Research Arm Test at day 90. It reported a large superiority of cerebrolysin on that test and a small-to-medium effect on a global measure combining 12 outcome scales ^[3]. A manufacturer-supported meta-analysis of nine randomised trials in 1,879 patients, using 30 to 50 mL a day for 10 to 21 days, reported a modest effect on the NIH Stroke Scale at day 30 ^[4].

The independent view is less favourable. The 2023 Cochrane review of cerebrolysin for acute ischaemic stroke, covering seven randomised trials and 1,773 participants, found moderate-certainty evidence that cerebrolysin makes little or no difference to all-cause death (risk ratio 0.96), and moderate-certainty evidence of an increase in the number of people with non-fatal serious adverse events (risk ratio 2.39), most marked with the 30 mL for 10 days schedule. None of the trials reported the review’s primary functional outcome, and the reviewers judged the risk of bias unclear or high on several counts, noting that the manufacturer supported three of the multicentre studies ^[5].

Alzheimer’s disease: a 24-week, double-blind trial in 279 patients with mild to moderate Alzheimer’s compared 10, 30 and 60 mL of cerebrolysin with placebo, infused five days a week for four weeks and then twice a week for eight weeks. At week 24 the 10 mL dose improved cognition on the ADAS-cog and global function; the 30 and 60 mL doses improved the global measure but not cognition, which the authors described as an inverted U-shaped dose response. Adverse event rates were similar across groups ^[6]. A 2015 meta-analysis of six placebo-controlled trials using 30 mL a day reported that cerebrolysin was more effective than placebo on cognition at four weeks and on global outcome at six months ^[7]. Its authors included company statisticians.

Vascular dementia: the 2019 Cochrane review found six randomised trials with 597 participants, mostly in China, Russia and Romania and mostly industry funded. Pooled cognitive scores and global function favoured cerebrolysin, but the evidence was rated very low quality, the reviewers concluded that any benefit may be too small to be clinically meaningful, and no new trials had been published since 2013 ^[8]. It is not licensed for dementia in the UK, US or EU, and neither NICE nor the FDA has evaluated it.

The CAPTAIN trials were two prospective, randomised, double-blind, placebo-controlled trials in patients with moderate to severe traumatic brain injury (Glasgow Coma Score 6 to 12). Patients received 50 mL of cerebrolysin or saline a day for ten days, then two further ten-day cycles of 10 mL a day, on top of usual care. A pre-planned meta-analysis of 185 patients found a small-to-medium effect in favour of cerebrolysin on a multidimensional ensemble of functional and neuropsychological scales at days 30 and 90, with comparable safety ^[9]. The trials were manufacturer sponsored and the endpoint is a composite the sponsor’s statisticians designed; no independent replication exists.

Across stroke, dementia and brain injury the pattern is the same: trials designed and analysed with the manufacturer report benefit on composite or global measures, while the largest single trial was neutral on its primary endpoint ^[2] and the independent Cochrane reviews find no effect on death, a possible increase in serious adverse events, and low- to very-low-quality evidence of benefit ^[5][8]. Cerebrolysin is not a fraud; it is a medicine with a genuine, contested evidence base that has not persuaded regulators in the UK, US or EU.

For a buyer, the practical point is that every one of these trials used intravenous infusion of 10 to 60 mL a day, given in hospital for 10 to 21 days or longer, in people with acute or chronic brain disease. There is no trial of cerebrolysin nootropic use, meaning cognitive enhancement in healthy people, no trial of intramuscular self-injection at home, and no evidence on the small daily doses described in nootropic forums.

In the trials, courses ran for 10 days (acute stroke ^[2]), 21 days (post-stroke recovery ^[3]), 30 days (brain injury, in three cycles ^[9]) or 12 weeks (Alzheimer’s ^[6]), with outcomes measured at 30 to 180 days. Effects, where reported, appeared over weeks of treatment and follow-up, not after single doses. Nothing is known about how quickly any effect would appear in a healthy person, because that has not been studied.

Published trials used 30 mL a day intravenously for 10 days in acute stroke ^[2], 30 mL a day for 21 days in post-stroke rehabilitation ^[3], 30 to 50 mL a day for 10 to 21 days across the stroke meta-analysis ^[4], 10, 30 or 60 mL five days a week for four weeks then twice weekly for eight weeks in Alzheimer’s disease ^[6], and 50 mL a day for 10 days followed by two 10-day cycles of 10 mL a day in traumatic brain injury ^[9]. The manufacturer refers prescribers to the Austrian summary of product characteristics for dose ranges by indication, route and duration ^[11].

These are the doses studies used in supervised hospital settings; they are not recommendations. The 5 mL ampoules sold by research suppliers correspond to the manufacturer’s smallest pack, and the low-dose intramuscular schedules described online come from users, not trials. Our peptide calculator is built for reconstituting single peptides and does not apply to a pre-mixed solution of unknown composition.

Cerebrolysin is supplied only as a solution for injection ^[10], in ampoules of a few millilitres and larger volumes for infusion; small volumes are given by intramuscular or slow intravenous injection and the 30 to 60 mL daily doses used in trials by intravenous infusion after dilution ^[2][3][6]. Every trial described above used intravenous infusion. There is no oral, nasal or subcutaneous product, and because it is a mixture of peptides it would be digested if swallowed. Products sold as cerebrolysin powder for reconstitution are not the licensed product in any form.

In the trials, adverse event rates were generally similar to placebo ^[2][3][6][9]. The exception is the Cochrane finding on serious adverse events: across three trials and 1,335 participants, cerebrolysin roughly doubled the number of people with non-fatal serious adverse events (risk ratio 2.39, 95% confidence interval 1.10 to 5.23), and the increase was larger with the 30 mL for 10 days schedule ^[5]. The reviewers could not say which events drove this, because reporting in the trials was incomplete.

The manufacturer describes reported adverse drug reactions as generally transient and mild, and lists three contraindications: hypersensitivity to any component, epilepsy, and severe renal impairment ^[11]. As an animal-derived biological product, cerebrolysin also raises the question of prion transmission from porcine tissue; the manufacturer controls for this in production, but a vial from an unregulated source carries no such assurance.

For people buying it outside a licensed supply chain, the additional risks are those of any imported injectable: counterfeits, improper storage during shipping, and self-administration without the dilution and infusion rate the label requires.

Cerebrolysin is authorised nationally in Austria, its country of manufacture, and in a number of other countries including Russia, China, South Korea and several Central and Eastern European and Asian markets, for indications that vary by country ^[5][10]. It has never been assessed centrally by the European Medicines Agency, and it holds no marketing authorisation from the MHRA in the UK or from the FDA in the US. In those countries it is an unlicensed medicine: it may not be advertised or sold to the public, and a store selling cerebrolysin injection in the UK or US is doing so outside medicines law. See our legal status overview and the UK, US and European pages.

Because it is a prescription medicine in the countries where it is licensed, imported vials sold by research suppliers have usually been diverted from a legitimate supply chain or manufactured by a third party. Neither is a licensed route to a UK or US buyer.

The licensed product is a ready-made aqueous solution that is kept at room temperature, protected from light and not frozen, and once diluted for infusion it is used promptly; the Austrian summary of product characteristics is the authoritative source for the exact conditions ^[11]. Unlike a freeze-dried peptide it is a ready-made solution, so there is no reconstitution step and the guidance in our peptide storage guide about lyophilised powders does not apply. Ampoules that have been frozen, exposed to heat in transit or that show cloudiness or particles should not be used.

Cerebrolysin cannot be verified by the mass spectrometry tests that work for single peptides, because it is a mixture with no single molecular weight. A certificate of analysis from a research supplier can, at best, confirm the batch number matches a genuine Ever Pharma lot and that the ampoule is intact; it cannot confirm potency. Compare cerebrolysin prices, read how to read a COA to understand what such a certificate can and cannot show, and see our list of third-party tested suppliers.

We track listings in the UK and the US. Our guides to third-party peptide testing and how to spot a fake peptide supplier explain the general checks; for an imported medicine, matching the packaging, batch number and expiry to the manufacturer’s format is the most useful one.