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Cerebrolysin

An enzymatically digested porcine brain extract of low-molecular-weight neuropeptides and free amino acids, given by injection or infusion in Europe and Asia for stroke, traumatic brain injury and dementia.

Also known as porcine brain peptide preparation, Cerebrolysin concentrate, brain-derived peptide preparation, Cerebrolysin, FPF-1070

Human RCT — Randomised controlled trials in humans, but not an approved product for this use.

This is the most-trialled compound in the class: CASTA randomised over a thousand acute stroke patients and CARS studied it in early rehabilitation, with the latter showing motor-function benefit. But the 2020 Cochrane review of Cerebrolysin in acute ischaemic stroke concluded there was no convincing evidence of benefit on death or dependence, flagged an excess of serious adverse events in the pooled data, and noted that most trials were funded by the manufacturer. Genuinely mixed, and the honest read is 'plausible, unproven, not free of risk'.

How it works

Cerebrolysin is not a single molecule. It is a controlled enzymatic breakdown of purified porcine brain protein, standardised to about 25% low-molecular-weight peptides with the balance being free amino acids, and the peptide fraction is claimed to carry the activity. In animal models it reduces excitotoxic and apoptotic neuronal death, dampens microglial activation, promotes neurogenesis in the dentate gyrus and improves synaptic density after ischaemia. Some of the effect is attributed to fragments with CNTF-like, GDNF-like and IGF-like activity, though the specific active species have never been definitively isolated - a fair criticism of the whole preparation. It also reduces amyloid burden and calpain activation in transgenic Alzheimer models.

Targets: Neurotrophic factor signalling (CNTF/GDNF/IGF-like activity), Calpain, Neurogenesis in the dentate gyrus, Microglial activation

Dosing

ProtocolDoseFrequencyRoute
Standard intramuscular courseMorning. Volumes above 5 mL are not given intramuscularly - it is a painful injection.—5 mL once daily for 10-20 consecutive daysintramuscular
High-dose intravenous stroke/TBI courseDiluted in 100-250 mL of saline and infused slowly over 20-60 minutes.—30-50 mL once daily for 10-21 daysintravenous
  • · Supplied as a ready-made aqueous solution containing roughly 215 mg of peptide concentrate per mL. Dosing is by volume, not milligrams.
  • · This is the regimen used in the CASTA and CARS stroke trials. Infusing it fast causes flushing, dizziness and heat sensations - slow the drip rather than stopping it.

Titration

For the intravenous route, start the infusion slowly for the first few minutes and watch for flushing or agitation before opening the drip up.

Cycling

Given in defined courses of 10-21 days, typically repeated two to four times a year rather than taken continuously.

Work out your exact syringe units →

Pharmacology

Half-life
Not meaningfully definable for a mixture. Neurotrophic-like activity in serum has been reported to persist up to about 24 hours after a single infusion.
Onset
Days. Clinical courses are 10-21 consecutive days and outcome differences in trials emerge over weeks to 90 days.
Routes
intramuscular, intravenous
Molecule
Standardised porcine brain-derived peptide and amino-acid preparation (peptide fragments under 10 kDa)

Handling

Diluent
Not applicable - supplied as a sterile ready-to-use solution in ampoules
Lyophilised
Not supplied lyophilised. Ampoules are stored below 25 degrees C.
Reconstituted
Use immediately once drawn up or diluted; the solution contains no preservative.
Light sensitive
Yes — keep it out of the light

Mixing

For infusion it is diluted into normal saline or Ringer's. Do not mix it in the same line with amino-acid infusion solutions or with solutions that shift the pH, and never combine it with an infusion containing a balanced amino-acid mix.

Side effects

  • commonFlushing, heat sensation or sweating during infusion— Almost always a consequence of infusing too fast.
  • commonInjection-site pain with intramuscular dosing— The volume is the problem; 5 mL is a lot of intramuscular fluid.
  • uncommonDizziness, agitation or confusion
  • uncommonNausea
  • rareHypersensitivity or allergic reaction to porcine protein— This is a porcine brain derivative given parenterally. Anaphylaxis is the reason a first dose is worth taking seriously.
  • rareSeizure or lowered seizure threshold— The manufacturer contraindicates it in status epilepticus; caution in any seizure disorder.

Do not use if

  • Known hypersensitivity to Cerebrolysin or to porcine protein.
  • Status epilepticus and grand mal epilepsy - the label contraindicates it.
  • Severe renal impairment.
  • Pregnancy and breastfeeding - no adequate data.

Combining it

  • synergysemax — Routinely combined in Eastern European post-stroke and TBI rehabilitation protocols.
  • redundantcortexin — Both are mammalian brain-derived peptide extracts used for the same indications. Running both is duplication rather than synergy.
  • synergynoopept — Standard Russian combination for post-injury cognitive rehabilitation.

What to monitor

  • · Renal function before a high-dose intravenous course.
  • · Observe for 20-30 minutes after the first dose for hypersensitivity.
  • · Track function with an actual instrument - NIHSS, mRS, MoCA - rather than impressions, since this is where the drug's own trials have been ambiguous.

Legal status

Approved and marketed in around 50 countries including much of Eastern Europe, Russia, China and parts of Asia and Latin America. Not approved in the US, UK or EU centrally.

References

  • Heiss et al. 2012, CASTA - Cerebrolysin in acute ischaemic stroke in Asia, Stroke (trial)
  • Muresanu et al. 2016, CARS - Cerebrolysin and Recovery After Stroke, Stroke (trial)
  • Ziganshina et al. 2020, Cerebrolysin for acute ischaemic stroke, Cochrane Database of Systematic Reviews (review)

Mechanism in depth

The mechanistic account of Cerebrolysin has an unusual shape: it is simultaneously the most-trialled compound in this class and the one whose active ingredient is least identified. Forty years on, nobody has isolated the molecule or molecules responsible for anything Cerebrolysin does. The attributed CNTF-like, GDNF-like and IGF-like activities are inferences from functional assays, not identifications. What the preclinical work does show consistently is a set of effects that look like a neurotrophic environment rather than a receptor drug: reduced excitotoxic and apoptotic neuronal death after ischaemia, suppressed calpain activation, dampened microglial activation, increased neurogenesis in the dentate gyrus, and preserved synaptic density. In transgenic Alzheimer models it reduces amyloid burden. The clinical shape of the compound follows from that: it does nothing acutely, it is given in 10-21 day courses, and outcome differences in trials emerge at 30-90 days. It is a rehabilitation adjunct rather than a drug you feel. The critical reading is that a mixture with no identified active principle, standardised by a manufacturing process rather than by content, and studied overwhelmingly in manufacturer-funded trials, is exactly the profile where you would expect apparent efficacy to shrink under independent scrutiny - which is precisely what the Cochrane reviews found.

What usually goes wrong

Infusing too fast is the everyday problem and produces flushing, heat, sweating and sometimes agitation. The fix is to slow the drip, not to stop the course - but people frequently do the second. The 5 mL intramuscular injection hurts because 5 mL is a lot of fluid for a muscle, and volumes above that are not given by that route. The serious failure is hypersensitivity: this is a heterologous protein preparation given parenterally, anaphylaxis is a real if rare event, and a first dose taken alone at home with no observation period is a bad decision that people make routinely because it is 'just a peptide'. It is not just a peptide; it is a porcine brain hydrolysate. Beyond safety, the commonest error is expectation: this compound does nothing acutely, and people who take a course expecting to feel sharper by day three conclude a batch is fake. The trials looked at 90 days for a reason. Finally, and more subtly, running repeated courses on the basis of subjective improvement during rehabilitation confuses the drug with natural recovery, which is exactly the confound the placebo arms of CASTA and CARS existed to control for.

Titration ladder

  1. —Day 1, intravenous route — Dose is by volume, not milligrams. Start the infusion slowly for the first 5 minutes and watch for flushing, heat sensation or agitation before opening the drip. The 30-50 mL dose goes into 100-250 mL of saline over 20-60 minutes.
  2. —Days 2-10 — Full dose at the established rate. Flushing and heat during infusion are almost always a rate problem - slow the drip rather than abandoning the course.
  3. —Days 11-21 — The CARS rehabilitation protocol ran 30 mL daily for 21 days starting 24-72 hours after stroke; CASTA ran 30 mL daily for 10 days in the acute phase. The 21-day rehabilitation-phase regimen is the one that produced a positive result.

Bloodwork worth running

MarkerWhenWhy it matters
Creatinine and eGFRBaseline before any course, and again before repeating a high-dose intravenous course.Severe renal impairment is a formal contraindication, and a 30-50 mL infusion is a substantial amino acid and nitrogen load. This is not optional before a high-dose intravenous course.Act if: An eGFR below 60 warrants a rethink and below 30 rules out the high-dose intravenous protocol entirely.
Liver enzymes (ALT, AST) and full blood countBaseline and at the end of a 10-21 day course.Baseline safety on a parenterally administered porcine-derived biological with a mixed adverse-event record. The 2020 Cochrane review flagged a possible excess of non-fatal serious adverse events in the pooled data, which is reason enough to have a baseline to compare against.Act if: Any new, sustained elevation means stop the course and investigate rather than push through to day 21.
Eosinophil count and clinical observation for hypersensitivityObserve for 20-30 minutes after the first dose. Check eosinophils if any rash, wheeze or flushing occurs that is not simply infusion-rate flushing.This is a porcine brain protein hydrolysate given parenterally. Anaphylaxis is the realistic serious risk, and it is why the first dose deserves supervision rather than a bathroom.Act if: Any urticaria, wheeze, facial swelling or hypotension not explained by infusion speed means stop permanently. Do not rechallenge a suspected hypersensitivity reaction to a heterologous protein.
NIHSS, modified Rankin Scale or MoCA, depending on why you are using itBaseline before the course, at the end of the course, and at 90 days - which is where the trials themselves looked.Not blood, but the most important measurement on this compound. Cerebrolysin's own large trials have been ambiguous, and impressions of improvement during a rehabilitation course are dominated by natural recovery. Without an instrument you cannot distinguish the drug from the passage of time.Act if: No measurable change at 90 days is the answer, not a reason for another course.

Pharmacokinetics

Bioavailability
100%
Crosses blood-brain barrier
partial
Metabolism
Proteolysis of the peptide fraction to free amino acids. About 75 percent of the preparation is already free amino acids before it goes in, and those enter the normal amino acid pool.
Elimination
Renal excretion of amino acids and small fragments through ordinary nitrogen handling. This is why severe renal impairment is a contraindication.

Receptor targets

  • Neurotrophic factor signalling (CNTF-like, GDNF-like, IGF-1-like activity) — No binding constants exist because no active species has been identified

    Functional neurotrophic effects in culture and in animal models. Attributed rather than demonstrated at the molecular level.

  • Calpain — Not quantified

    Reduced calpain activation after ischaemic and excitotoxic injury, limiting proteolytic damage to the cytoskeleton. One of the better-characterised preclinical effects.

  • Microglial activation — Not applicable

    Dampened neuroinflammatory response after injury, which is plausibly a large part of whatever clinical effect exists.

  • Dentate gyrus neurogenesis — Not applicable

    Increased neurogenesis and preserved synaptic density in rodent models. The proposed substrate for the delayed, rehabilitation-phase benefit seen in CARS but not in CASTA.

Trials

  • CASTA - Cerebrolysin Acute Stroke Treatment in Asia Phase 4, double-blind, placebo-controlled, randomised · n=1070 · 1.5 weeks · 2012

    Combined global directional test of modified Rankin Scale, Barthel Index and NIHSS at day 90, after 30 mL daily for 10 days. Negative - no significant difference between Cerebrolysin (529) and placebo (541). A post-hoc subgroup analysis suggested a signal in severely affected patients with NIHSS above 12, where mortality was 10.5 percent versus 20.2 percent, but that is a post-hoc finding in a negative trial and should be read as hypothesis-generating.

  • CARS - Cerebrolysin and Recovery After Stroke Randomised, placebo-controlled, double-blind, multicentre · 3 weeks · 2016

    Action Research Arm Test score at day 90, with 30 mL daily for 21 days started 24-72 hours after stroke alongside standardised rehabilitation. Positive - Mann-Whitney estimator 0.71, p<0.0001, described by the authors as a large superiority over placebo. The authors themselves noted the study was exploratory with a relatively small sample size.

  • ESCAS - Speech Therapy Combined With Cerebrolysin in Nonfluent Aphasia After Acute Ischaemic Stroke Randomised pilot · 2025

    Recovery of nonfluent aphasia when Cerebrolysin is added to speech therapy after acute ischaemic stroke. A pilot study, published in Stroke in 2025, from the same investigator group that ran CARS.

What to expect, and when

Nothing acute. Neurotrophic-like activity has been reported in serum for up to about 24 hours after a single infusion, which is the justification for daily dosing. Clinical courses run 10-21 consecutive days. In CASTA the endpoint was day 90 and there was no difference; in CARS the endpoint was also day 90 and there was. Any real effect emerges over weeks in the context of active rehabilitation, not in isolation - CARS delivered it alongside a standardised rehabilitation programme, and that is not incidental to the result. Courses are repeated two to four times a year rather than run continuously.

Stacking and comparisons

The formulation interactions matter more here than the pharmacological ones. Do not put Cerebrolysin in the same line or the same bag as a balanced amino acid infusion - the manufacturer is explicit about it, and given that three quarters of the product is free amino acids the reasoning is not obscure. Do not combine it with solutions that shift the pH. Dilute into normal saline or Ringer's and nothing else. Pharmacologically, the standard Eastern European post-stroke combinations pair it with Semax or Noopept and there is a long tradition behind that, though no combination trial. Running it alongside Cortexin is duplication rather than synergy - both are mammalian brain hydrolysates aimed at the same indications, and there is no reason to believe bovine and porcine extracts do different things. The one combination worth thinking hard about is with anything that lowers seizure threshold, since the label contraindicates Cerebrolysin in status epilepticus and lowered seizure threshold appears in its adverse-effect profile.

Against everything else in this class, Cerebrolysin is in a different evidential category - it has randomised placebo-controlled trials in the thousands of patients and independent Cochrane scrutiny, which nothing else here has. The honest summary of that evidence is genuinely mixed rather than positive: the largest acute stroke trial was negative on its primary endpoint, the rehabilitation-phase trial was strongly positive but exploratory and small, and the Cochrane reviews found little to no effect on death or dependence plus a possible excess of non-fatal serious adverse events, in a literature dominated by manufacturer funding. That is a more useful thing to know than any confident claim in either direction. Against Cortexin: same category of product, bovine rather than porcine, with a fraction of the trial evidence - Cortexin has essentially no randomised controlled data. Against Semax: Semax is cheaper, needle-free and self-administrable, with much weaker evidence; the Eastern European practice is to use both. Against the alternative of intensive structured rehabilitation on its own, which is what the placebo arms received: that alternative did most of the work in both trials, and it remains the intervention with the best evidence for stroke recovery by a wide margin.

Rough cost

$150–$900/month. Pricing varies enormously by source country. A box of five 10 mL ampoules typically runs 60-150 USD from Eastern European or Asian pharmacy sources. A standard 10-day 5 mL intramuscular course therefore lands around 100-200 USD. The 30 mL daily intravenous course for 21 days needs 630 mL of product and runs into the high hundreds or beyond, plus the cost of having someone competent run the infusion. Anyone quoting a cheap monthly figure is describing the intramuscular course, not the regimen that generated the trial data.

Genuinely uncertain

  • No active molecular species has ever been isolated from Cerebrolysin. Forty years and thousands of trial participants later, nobody knows what in it does anything.
  • The number of participants in CARS was not stated in the abstract I could access and I did not resolve it.
  • Pharmacokinetics are not definable for a mixture and have never been meaningfully characterised. Volume of distribution, clearance and protein binding are all inapplicable or unmeasured.
  • The reported persistence of neurotrophic-like activity in serum for about 24 hours is the basis of daily dosing but I could not resolve the primary source for that figure.
  • The discrepancy between CASTA (negative, acute phase, 10 days) and CARS (positive, rehabilitation phase, 21 days) has never been resolved. It may reflect timing, duration, the concurrent rehabilitation programme, or chance.
  • The Cochrane finding of a possible increase in non-fatal serious adverse events (RR 2.15) comes with wide confidence intervals and low-certainty evidence, and its real-world significance is unclear.
  • Batch-to-batch consistency of an enzymatic hydrolysate standardised by process rather than content is asserted by the manufacturer and not independently verifiable.
  • The extent to which manufacturer funding across most of the trial programme has shaped the apparent effect size is a documented concern that cannot be quantified from outside.
  • How much of the peptide fraction crosses the blood-brain barrier in a human is not established.

Papers