Cortexin
Also known as: Cortexin (Kortexin / Кортексин) · Cerebral cortex polypeptide complex · Cattle/pig cerebral cortex polypeptides · Cortexin-like peptide mixture · A water-soluble polypeptide fraction (MW <10 kDa) — NOT a single named amino-acid code
Research focus
Cerebral cortex / central nervous system — neuroprotection in ischemic and traumatic brain injury, cognitive disorders, and pediatric neurology
US regulatory status
Not FDA-approved · Not compoundable
Evidence rating
Theoretical
Origin
Cortexin is a Russian-registered prescription drug, not a synthetic single peptide. It is a low-molecular-weight (reported <10 kDa) water-soluble polypeptide fraction extracted from the cerebral cortex of young cattle and pigs, supplied as a lyophilized powder reconstituted for intramuscular injection. It belongs to the older Soviet/Russian "cytomedine" tradition of organ-derived peptide extracts. The St. Petersburg Institute of Bioregulation and Gerontology group around Vladimir Khavinson (with collaborators such as Ryzhak, Kuznik and Lin'kova) classifies Cortexin among its "peptide bioregulators" and geroprotectors, and has used it as the starting material from which shorter synthetic peptides (e.g. the tripeptide EDR / Glu-Asp-Arg) were derived and studied. Cortexin itself, however, is a multi-component biological extract registered and marketed primarily in Russia and other CIS countries; it is not a defined-sequence Khavinson "Cytogen" and is not approved in the United States or the EU.
Plain-language summary
Cortexin is a Russian prescription injectable made from the brain cortex of cattle and pigs — a mix of small proteins and amino acids, not one defined molecule. In Russia and nearby countries doctors have used it for decades for stroke recovery, head injury, and various cognitive and childhood neurological conditions, and there are hundreds of published human reports. The catch: most of those reports are small, single-center, often unblinded studies published in Russian-language journals, and the strongest independent analysis — a 2023 Cochrane review that pooled a Cortexin trial with similar brain-extract drugs — found no benefit on survival and flagged a possible increase in non-fatal serious side effects for the drug class. So Cortexin has far more human data than the lab-made Khavinson peptides, but the quality of that data is low and the independent evidence is not encouraging. It is not FDA-approved and is not a verified product in the US.
Claimed mechanism (as reported)
Marketing and Russian-language publications describe Cortexin as a "tissue-specific" neuroprotective and neurotrophic agent, and propose that its polypeptide and amino-acid components reportedly reduce oxidative stress, modulate excitatory/inhibitory neurotransmission, and influence expression of neurotrophic and apoptosis-related genes. An independent rat study (Kurkin et al., PLoS One 2021) reported in-vitro binding of Cortexin to glutamatergic (AMPA, kainate, mGluR1/5) and GABA-A receptors and measurable blood-brain-barrier penetration of radiolabeled material, offering a possible pharmacological basis. Khavinson-group work proposes that cortexin-derived short peptides (e.g. EDR) bind histone H1.3 and act epigenetically on neuronal genes. As a multi-component extract, Cortexin has no single, well-defined molecular target; the proposed mechanisms remain partly characterized and are not established as the cause of any clinical effect.
Evidence summary
Cortexin is unusual among the compounds this hub covers in that a large human literature genuinely exists — over 200 PubMed-indexed records, including dozens of small clinical studies in stroke, traumatic brain injury, cognitive impairment and pediatric neurology. However, the great majority are small (typically n=30–110), single-center, frequently unblinded studies published in Russian-language journals (most often Zh Nevrol Psikhiatr Im S S Korsakova), with little independent Western replication. The most rigorous independent assessment — a 2023 Cochrane systematic review of Cerebrolysin and Cerebrolysin-like agents that incorporated a 272-participant Cortexin randomized trial — concluded these cattle/pig brain-derived peptide mixtures probably have no beneficial effect on all-cause death in acute ischemic stroke and indicated a potential increase in non-fatal serious adverse events for the class. Independent preclinical work (rat ischemia models, sensory-neuron and ischemia-reperfusion studies from Russian and Turkish groups) reports neuroprotective signals, but preclinical effect does not establish clinical benefit. Given the weak methodology, the null/negative independent human evidence, and the absence of large, well-blinded, independently-replicated randomized controlled trials in peer-reviewed English-language literature as of 2026, the published record does not support claims of established human efficacy. Rated Theoretical: real human studies exist but are not strong enough to demonstrate a reliable clinical effect. An independent 2021 systematic review (Alsulaimani & Quinn, Cerebral Circulation – Cognition and Behavior) could not meta-analyze Cortexin because only one small RCT (n=80) met inclusion, rating the class evidence low-to-very-low certainty; Russian evidence syntheses (a 2021 CyberLeninka meta-analysis and a 2013 health-technology assessment) independently reached the same limiting conclusion — only about two randomized stroke trials exist, graded evidence level C, with probable pseudo-randomization in some pediatric "RCTs." The newest human study, the 2026 DIACORT RCT (n=110), remained open-label. No trials are registered on ClinicalTrials.gov (the trial literature is Russian-registry/Russian-language).
What the research reports
Cerebrolysin for acute ischaemic stroke (Cochrane systematic review; incorporates a Cortexin randomized trial)
Grade BZiganshina LE, Abakumova T, Nurkhametova D, Ivanchenko K · Cochrane Database of Systematic Reviews · 2010–2023 (latest update 2023)
Reported finding: For cattle/pig brain-derived peptide mixtures (including the Cortexin trial), the review found moderate-certainty evidence of no beneficial effect on all-cause death in acute ischemic stroke, and indicated a potential increase in non-fatal serious adverse events for the drug class. This is the strongest independent evidence base touching Cortexin and it is null-to-unfavorable.
Sample: 7 RCTs, 1773 participants total; the added Cortexin RCT contributed 272 participants
Methodology: B — independent systematic review/meta-analysis; but pooled trials individually at unclear/high risk of bias
Limitations: Cortexin contributed only one trial; manufacturer involvement in related trials; component studies at unclear/high risk of bias; no data on functional dependence or quality of life.
Russian clinical studies of Cortexin in acute and recovery-period ischemic stroke (representative cohort series)
Grade CBelova LA, Mashin VV, Abramova VV et al.; also Khabirov FA et al.; Evzel'man MA et al. · Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova (Zh Nevrol Psikhiatr Im S S Korsakova) · 2013–2024
Reported finding: Repeated low-dose Cortexin (commonly 10–20 mg/day IM for 10 days, sometimes repeated courses) was reported to improve regression of neurological deficit and cognitive scores (NIHSS, MMSE, MoCA) versus basic therapy. Reported benefits are modest and were not independently replicated; one head-to-head study found Cortexin less effective than the comparator Cellex.
Sample: Typically n=30–90 per study (e.g. 90-patient three-arm cohorts; a 40-patient randomized Cellex-vs-Cortexin comparison)
Methodology: C — small single-center studies, mostly Russian-language, frequently unblinded, surrogate clinical scales
Limitations: Small samples, single centers, limited or no blinding, heterogeneous protocols, reliance on rating-scale surrogates, publication concentrated in one journal.
Peptide bioregulators as geroprotectors / neuroprotective peptide bioregulators (Khavinson-group reviews placing Cortexin in context)
Grade CKhavinson VKh, Kuznik BI, Ryzhak GA; Umnov RS, Lin'kova NS, Khavinson VKh · Advances in Gerontology (Uspekhi Gerontologii); Molecular Biology (Mol Biol Mosk) · 2003–2019
Reported finding: These papers classify Cortexin among Russian peptide bioregulators used in elderly and pediatric neurology, summarize claimed clinical applications, and propose mechanisms — including that cortexin-derived short peptides (e.g. EDR) may bind histone H1.3 and act epigenetically on neuronal genes such as Fkbp1b. They report claims and proposed mechanisms rather than independently-verified outcomes.
Sample: Not applicable (reviews and in-silico/in-vitro mechanistic work)
Methodology: C — narrative reviews and mechanistic/molecular-modeling papers from the originating research group; not independent efficacy trials
Limitations: Single-group authorship, potential conflict of interest, mechanistic/in-silico emphasis, no independent replication of clinical claims.
Independent preclinical neuroprotection studies of Cortexin (rodent ischemia, ischemia-reperfusion, and cultured sensory neurons)
Grade CKurkin DV, Bakulin DA, Tyurenkov IN et al. (Volgograd); Guven C, Türk A et al. (Turkey); Yazar U, Ayar A (Turkey) · PLoS One; Neurological Research; Neuroendocrinology · 2021–2025
Reported finding: Reported that Cortexin (1–3 mg/kg/day in rats) reduced infarct size and oxidative-stress markers, improved antioxidant status, modulated inflammation/calcium-signaling biomarkers (OPG/RANK/RANKL, TRPC1), crossed the blood-brain barrier in mice, and bound glutamatergic/GABAergic receptors in vitro. These are mechanistic and preclinical signals, not evidence of clinical efficacy.
Sample: Rodent cohorts (e.g. n=35 rats across 5 groups) and cell-culture preparations
Methodology: C — animal and in-vitro studies only; small group sizes; no human outcomes
Limitations: Animal/in-vitro only; small samples; manufacturer-affiliated co-authors on some work; preclinical neuroprotection frequently fails to translate to humans.
The efficacy and safety of animal-derived nootropics in cognitive disorders: systematic review and meta-analysis
Grade BAlsulaimani RA, Quinn TJ · Cerebral Circulation - Cognition and Behavior · 2021
Reported finding: This independent (non-sponsor) review could not meta-analyze Cortexin because only one small randomized trial (n=80) met inclusion criteria; across the animal-derived nootropic class it rated certainty of evidence low-to-very-low and effect sizes "probably less than would be considered clinically relevant."
Sample: Cortexin: a single eligible RCT (n=80)
Methodology: B (review method) / D (Cortexin evidence) — rigorous independent English-language SR/meta-analysis, but only one small Cortexin RCT met inclusion so no pooled estimate was possible
Limitations: Documents the thinness of Cortexin’s RCT base rather than a positive effect; included trials at moderate-to-high risk of bias.
Cortexin in neurological complications of type 2 diabetes mellitus (DIACORT multicenter randomized trial)
Grade CPutilina MV et al. · Zhurnal nevrologii i psikhiatrii im. S.S. Korsakova · 2026
Reported finding: Adding a 10-day course of intramuscular Cortexin to standard therapy was reported to produce larger 3-month improvements in cognition (MoCA), anxiety/depression (HADS) and neuropathy symptom scores than standard care; the report also claimed a greater HbA1c reduction, which is biologically implausible for a 10-day peptide course and points to expectancy/confounding.
Sample: n=110 (55 Cortexin add-on vs 55 standard care)
Methodology: C — randomized and multicenter, but open-label, standard-care-controlled (no placebo/blinding), modest n, soft self-report endpoints
Limitations: Unblinded, no placebo, sponsor-aligned authorship, subjective endpoints; the implausible HbA1c signal undermines confidence.
Administration reported in studies
In published Russian clinical studies Cortexin is reconstituted from lyophilized powder and given by intramuscular injection, most commonly 10 mg/day (children and lower-weight patients) or 20 mg/day (adults), for a 10-day course, sometimes as two 10-day courses separated by a 10-day interval or repeated quarterly over a year. Preclinical rodent work used roughly 1–3 mg/kg/day intramuscularly/parenterally for about 10 days. This is a summary of research conditions — not a dosing recommendation and not a protocol endorsed by TPC.
This section reports what published studies describe. It is not a dosing recommendation from TPS.
Safety record
Within its Russian regulatory context Cortexin is generally described as well tolerated, with injection-site reactions and occasional allergic/hypersensitivity responses the most cited issues, and Russian-language studies typically report no serious adverse events in their small cohorts. Two important caveats temper this. First, the 2023 Cochrane review of the broader cattle/pig brain-extract drug class (which incorporated a Cortexin trial) found moderate-certainty evidence of a potential increase in non-fatal serious adverse events. Second, because Cortexin is an injectable extract derived from animal central-nervous-system tissue, theoretical concerns about prion and other adventitious-agent transmission have been raised; the manufacturer/Khavinson-group literature asserts that the production process removes infectious agents, nucleic acids and prion proteins, but this has not been independently validated to Western regulatory standards. Long-term and large-scale independent safety data in humans are lacking, and product purchased outside the regulated Russian channel is of unknown identity and sterility.
US legal status
Not FDA-approved for any use. Not on the FDA 503A compoundable bulk drug substances list, and not legally compoundable for human clinical use in the United States. Cortexin is an injectable animal-tissue-derived biological registered as a drug in Russia/CIS, not in the US, and importing or selling it for human use is not authorized here; it appears in US channels only as an unapproved foreign drug or "research chemical." Vendors in that channel are unregulated and not verified by TPC. This is regulatory information, not legal advice.
Open research questions
- ? Does Cortexin produce any clinically meaningful benefit on hard outcomes (death, functional dependence, quality of life) in large, adequately powered, double-blind, placebo-controlled trials — given that the one independent Cochrane analysis incorporating a Cortexin trial was null on survival?
- ? Can the modest improvements in rating scales (NIHSS, MMSE, MoCA) reported in small Russian single-center studies be reproduced by independent investigators outside Russia with blinded assessment and pre-registered protocols?
- ? What exactly is in the extract, batch-to-batch — which polypeptides and amino acids are present, in what amounts, and how consistent is composition across lots and manufacturers?
- ? How robust are the prion/adventitious-agent safety assurances for an injectable derived from bovine and porcine CNS tissue, and what is the real long-term adverse-event profile in large populations rather than small cohorts?
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