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Cortexin

Also known as Korteksin, bovine cerebral cortex polypeptide complex

Undefined polypeptide extract of bovine brain cortex, registered in Russia and injected for cognitive complaints.

early-clinical Neuro & cognition approved drug

At a glance

Category
Neuro & cognition
Status
approved drug
Made from
animal-derived Acetic-acid extract of the cerebral cortex of cattle, described in some sources as bovine or porcine, freeze-dried with glycine as bulking agent.
Route
intramuscular injection only (the lyophilisate is dissolved in saline or procaine solution)
Half-life
Not definable. The manufacturer's own product information states that the composition - a complex of polypeptide fractions - does not permit conventional pharmacokinetic analysis of individual components. That is an admission that no pharmacokinetics exist, presented as a property of the product.
Onset
No acute effect claimed; given in courses of 10 days and assessed over weeks

Registered medicine in Russia (manufacturer Geropharm, St Petersburg; lyophilisate for solution for intramuscular injection, 10 mg, with a 5 mg presentation also marketed) 89 and in several other post-Soviet states, where it became one of the most-prescribed neurological agents. Never assessed by the EMA or FDA and not registered in the EU or US. It is a crude tissue extract, not a defined molecular entity.

Doping status: Not listed by name; as a substance without EMA or FDA approval it falls under the S0 residual category outside the countries where it is registered

Checked against the WADA 2026 Prohibited List. For a specific product and country, Global DRO is the lookup athletes are expected to use — the List names substances, not brand names.

Bovine central nervous tissue is the specific reason the theoretical TSE concern attaches to this product and not to a synthetic peptide; whether a given batch met the required sourcing controls cannot be checked by the user.

Mechanism of action

Cortexin is a water-soluble low-molecular-weight fraction obtained by acetic-acid extraction of the cerebral cortex of cattle (and in some descriptions pigs), sold as a lyophilised powder with glycine as bulking agent. The stated content is a mixture of polypeptides in roughly the 1-10 kDa range together with free amino acids, vitamins and trace elements. No single constituent is identified as the active principle.

That is the central problem with the entire preparation, and it is a problem of kind rather than degree. A medicine whose active ingredient is 'a complex of polypeptide fractions' cannot be characterised, cannot be assayed for potency in any meaningful way, cannot have its pharmacokinetics measured, and cannot be reproduced by anyone else. Batch-to-batch equivalence rests on the manufacturing process rather than on a specification of what the product contains. Every mechanistic claim made for Cortexin is therefore a claim about an undefined mixture.

The proposed mechanism is 'tissue-specific neurotrophic and neuroprotective action': promotion of neuronal survival, antioxidant effects, modulation of glutamate excitotoxicity, and inhibition of apoptosis. Russian work has reported inhibition of caspase-8 activity and effects on neurotrophin signalling. A 2023 study in cultured rat sensory neurons reported protection against high-glucose-induced neuropathy 6.

There is no demonstrated target engagement in the human central nervous system, no validated activity biomarker, and no persuasive account of how a mixture of 1-10 kDa peptides injected into muscle would reach the brain in pharmacologically relevant quantity. Peptides of that size are cleared rapidly by peptidases and do not cross the blood-brain barrier by any described route. The same objection applies to Cerebrolysin and has never been answered for either.

What the research shows

Cortexin has a large Russian-language clinical literature and essentially no evidence that meets contemporary international standards. There is no multicentre placebo-controlled randomised trial published in an internationally indexed journal, no Cochrane review, no independent replication outside the post-Soviet region, and no regulatory assessment by the EMA or FDA. The volume of publication should not be mistaken for weight of evidence - the design of the studies is the limiting factor, not their number.

Research in humans

Representative examples: an open (that is, unblinded and uncontrolled) trial of Cortexin in brain ischaemia, part of an all-Russian screening programme reported to have involved tens of thousands of patients across dozens of cities at 10 mg per day for 10 days 3; a 2018 multicentre study of 635 children aged 3-7 with ADHD, speech delay, perinatal CNS injury or asthenic syndrome, reporting benefit on cognitive measures 5; and a 2004 study on memory and attention in a military medical journal 1. The recurring pattern is open-label design without a placebo arm, clinician-rated or subjective outcomes, short follow-up, no protocol registration, and publication in a small set of Russian journals - most often Zh Nevrol Psikhiatr Im S S Korsakova. An open trial in a condition with a variable natural course cannot distinguish drug effect from recovery, regression to the mean or expectation.

Animal and lab research

Preclinical work reports neuroprotection in rodent models of toxic CNS damage, neonatal injury and developmental delay 7, inhibition of brain caspase-8, and protection of cultured sensory neurons against hyperglycaemic injury 6. A 2007 study compared behavioural effects of Cortexin and Cerebrolysin injected into the brain ventricles 2 - a route that bypasses the blood-brain barrier problem entirely and therefore says nothing about intramuscular use. As with the clinical work, most of it comes from Russian laboratories with links to the manufacturer or the originating institute.

Caveats. The decisive limitation is that the product has no characterisable active ingredient, so no study of it can be replicated by an independent group working from a published composition. Beyond that: absence of blinding and placebo control in most clinical reports; soft, examiner-dependent endpoints; short follow-up; no registered protocols or pre-specified primary endpoints; manufacturer involvement in study conduct and reporting; and publication almost exclusively in Russian in journals with limited external scrutiny. The 'screening' programmes involving very large patient numbers are post-marketing observational exercises, not trials, and generate no comparative evidence at all. There is also the safety issue inherent in any bovine central nervous system extract - see contraindications.

What it is used for

  • In Russia, registered for cerebrovascular disease, traumatic brain injury, encephalitis and encephalomyelitis, cognitive impairment, epilepsy, asthenic conditions, and developmental and speech delay in children including cerebral palsy
  • Widely used in paediatric neurology in Russia and neighbouring states for developmental and speech delay - an application for which the evidence is particularly weak and the population particularly unable to consent
  • Used off-label outside those countries as a self-administered nootropic, obtained through grey-market import

Dosing

Dose
Registered dosing: adults and children over 20 kg, 10 mg per day intramuscularly; children under 20 kg, 0.5 mg per kilogram per day. That 10 mg is also the maximum single and daily dose for those indications. The one exception on the label is hemispheric ischaemic stroke in the acute and early recovery period, where adults receive 10 mg twice daily (morning and evening) for 10 days - an indication-specific regimen, not a general permission to double the dose.
Frequency
once daily, in the morning
Route
intramuscular; the lyophilisate is dissolved in 1-2 ml of 0.9% sodium chloride, water for injection, or 0.5% procaine
Duration
Courses of 10 days, repeated after 3-6 months
  • These figures come from an approved Russian label 89, so they are not invented - but the approval rests on the evidence base described above.
  • Because the active ingredient is undefined, 'a 10 mg dose' means 10 mg of lyophilised extract, not 10 mg of any identified active substance. Dose is a mass of powder, not a pharmacological quantity.
  • There is no dose-finding study, no dose-response curve and no maximum tolerated dose.
  • Procaine as a diluent introduces its own allergy risk and is contraindicated in people sensitive to ester local anaesthetics.
  • Outside its registered indications Cortexin is self-administered as a nootropic 'course', obtained through grey-market import. That circulating pattern is set out under Protocols; it diverges from the label by being for cognitive enhancement in healthy people, for which there is no evidence.

These figures describe what the literature and published protocols report. They are not advice and not a dosing instruction.

Protocols

Registered Russian course (adults and children over 20 kg)

approved product information

Source: Geropharm product information, Cortexin lyophilisate for intramuscular injection

Days 1-1010 mg once daily by intramuscular injection, dissolved in 1-2 ml of 0.9% sodium chloride, water for injection or 0.5% procaine
After 3-6 monthsthe 10-day course may be repeated

Intramuscular only. Ten milligrams is the maximum single and daily dose for the indications covered by this schedule; the label's only twice-daily regimen is 10 mg morning and evening for 10 days in hemispheric ischaemic stroke, repeated after 10 days, which is a separate indication rather than a dose escalation of this course. Children under 20 kg receive 0.5 mg per kg per day. Because the product is an undefined tissue extract, 10 mg is a mass of lyophilised powder rather than a pharmacological quantity of any identified substance. Procaine as diluent carries its own allergy risk in people sensitive to ester local anaesthetics.

Self-administered nootropic course (user-reported)

user protocol — not validated

Source: Nootropic forum reports and grey-market import

This is not a validated schedule. It is a pattern that circulates among users and sellers, reproduced because it is what people actually follow — not because it has been tested. No trial established these doses, this interval or this duration, and nobody is checking what is in the vial. Treat every number below as an assertion, not a finding.

Reported daily amount10 mg once daily intramuscularly, the label figure, reconstituted in saline the user sources
Reported course lengthabout 10 days, copied from the registered course, sometimes repeated
Reported stackingoften run alongside cerebrolysin, semax or selank

This mirrors Cerebrolysin. The label directs a 10 mg, 10-day intramuscular course of an undefined bovine-cortex extract, on prescription, for neurological indications; what circulates outside those countries is self-injection of grey-market imported vials by healthy people for cognitive enhancement, copying the same 10 mg / 10-day course for an unstudied purpose. Because the active ingredient is undefined, even the label 'dose' is a mass of powder rather than a pharmacological quantity, so a self-doser has nothing to titrate against. There is no published basis for nootropic use, and reports are subjective and confounded by stacking. Grey-market vials cannot be assumed to be the registered preparation, and both the bovine central-nervous-tissue TSE concern and the procaine-diluent allergy risk apply to material handled outside a pharmacy.

Schedules are reproduced as their source states them. Units, IU and milligrams explains why the figures are not interchangeable between products.

Reconstitution

Vial sizes
5 mg, 10 mg (lyophilisate for intramuscular injection)
Solvent
0.9% sodium chloride, water for injection, or 0.5% procaine solution, 1-2 ml per vial, according to the manufacturer's label
Storage
Powder at 2-20 °C protected from light according to the label. The reconstituted solution is intended for immediate use - it contains no preservative and should not be kept.

Worked example

10 mg vial + 2 ml 0.9% sodium chloride = 5 mg/ml; the full vial is the usual daily adult dose.

Direct the diluent down the vial wall and swirl gently rather than shaking, to limit foaming. Do not use if the solution is cloudy or contains particles. Unlike synthetic single peptides, this is a biological extract with no bacteriostatic preservative, so multi-day storage after reconstitution is not appropriate. Product bought outside the official distribution chain cannot be assumed to be the registered preparation.

Work it out for Cortexin

Safety

Side effects

  • The Russian prescribing information lists as rare: allergic reactions, skin reactions including rash, urticaria and itching, headache, dizziness, excitation, tachycardia, sleep disturbance and injection site reactions 9
  • The manufacturer's own product page goes further and states that adverse effects are not reported, with individual hypersensitivity possible 8 - for a crude animal tissue extract given by injection, a claim of that shape reflects limited systematic pharmacovigilance rather than demonstrated safety
  • Reactions attributable to the procaine diluent where it is used, rather than to the extract itself 9

Do not use if

  • Hypersensitivity to the preparation 89 or, where procaine is used as diluent, to ester-type local anaesthetics
  • Pregnancy - contraindicated in the Russian prescribing information for want of clinical trial data 9
  • Breastfeeding - contraindicated in the same document; the feed should be stopped if treatment is necessary 9
  • Under 18 is not a listed contraindication - paediatric dosing at 0.5 mg/kg per day under 20 kg is on the label 9 - but lidocaine as a solvent is specifically not recommended in children, as it may worsen adverse reactions 9
  • As a bovine central nervous system extract, Cortexin belongs to the class of products for which transmissible spongiform encephalopathy risk is a formal regulatory concern. European regulators impose strict sourcing and processing requirements on ruminant CNS-derived material precisely for this reason; whether any given batch meets those requirements cannot be verified by the user. This risk is theoretical and unquantified, not demonstrated, but it is not zero and it is specific to extracts of this kind.
  • Paediatric use for developmental delay is a registered indication in Russia but rests on open-label evidence in a population that cannot consent - a reason for caution rather than reassurance

Interactions

Not systematically studied; no formal interaction trials have been published. The Russian prescribing information gives no drug interactions but does give two solvent instructions: lidocaine as a solvent is not recommended, particularly in children, because it may worsen adverse reactions, and where procaine is used its own contraindications and age restrictions apply 9. Beyond that, where procaine is the diluent the interactions of procaine itself apply, including with sulfonamides.

Sources