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Peptide mixtureLimited humanNot FDA approved

Cortexin

Cortexin (polypeptide extract of cattle and pig brain cortex)

Last reviewed October 27, 2026 · 15 sources · Written for general readers · Compare with another compound →

The bottom line

Cortexin is a mix of peptides taken from cattle and pig brain and given as shots in Russia after stroke and for other brain problems. Many Russian studies report benefits, but most compared it with usual care, and independent reviewers rate the evidence as weak. It is not approved in the United States.

Where the evidence stands

What it is

Cortexin is a mix of small proteins and peptides extracted from the cerebral cortex, the outer layer of the brain, of cattle and pigs. Most of its peptides weigh roughly 1,000 to 10,000 daltons, a unit of molecular weight.[1] Because it is a mixture, it has no single formula or sequence.

Purified animal tissue extracts of this kind, including Cortexin, are used in Russia and several other former Soviet countries, mainly after stroke, brain injury and problems with blood flow to the brain.[1] In studies it is given as a shot into a muscle or a vein. It has no US drug label.[2]

Name
Cortexin (Cortexin (polypeptide extract of cattle and pig brain cortex))
Other names
Korteksin
Type
Peptide mixture

How it works

How Cortexin works is not well understood because it is a blend of many peptides.

  • In mice, a radioactively tagged form of Cortexin crossed into the brain.[1][3]
  • In lab tests, it bound to several receptors for glutamate and GABA, two key chemical messengers in the brain.[1]
  • In rats with long term reduced blood flow to the brain, it improved antioxidant defenses.[1]

These findings come from animal and lab work, some of it funded by the drug's maker.

What the research shows

We keep animal and human evidence apart. A result in animals is a reason to study something in people, not proof that it works in people.

Animal and lab studies

Some benefit in rat stroke and brain injury models

  • In a study of 224 rats with blocked or narrowed brain arteries, Cortexin improved nerve function and reduced movement and memory problems, much like Cerebrolysin, another brain extract.[1]
  • In the sudden stroke model, it shrank the area of dead brain tissue.[1]
  • In young rats with brain damage from alcohol before birth or from low oxygen just after birth, 20 days of Cortexin shots or suppositories reduced nerve problems, improved movement tests and left more healthy nerve cells than placebo.[3]

Limit: Only rats were tested, and in the 2021 study three authors worked for the drug company that funded it.[1]

Human studies

Many Russian trials, few with a true placebo group

  • Acute stroke, placebo controlled: a 2014 Russian trial of 272 stroke patients compared two courses of Cortexin shots into a muscle, one course followed by placebo, and two courses of placebo over 70 days. The authors reported the best results with two courses, but the summary gives no numbers.[7]
  • A 2023 Cochrane review, an independent summary of trials, included that 272 person trial and judged its risk of bias unclear in most areas. It concluded that Cerebrolysin and similar brain extracts, including Cortexin, probably make little or no difference to the chance of dying after stroke.[8]
  • Acute stroke, route comparison: a 2025 double blind trial of 490 adults compared Cortexin into a vein with Cortexin into a muscle. At 90 days, about 94% and 87% could live without help. There was no placebo only group, so this shows the two routes were similar, not that Cortexin works.[9]
  • Long term reduced blood flow to the brain: a 2018 trial assigned 189 adults, average age 64, to one of two Cortexin regimens or usual care alone, with 10 day courses repeated after six months. The Cortexin groups had fewer nerve symptoms, less tiredness and better sleep. Effects on mood and anxiety were small and showed up only after repeated courses.[4]
  • Type 2 diabetes with nerve problems: a 2026 trial in 110 adults compared 30 days of Cortexin plus standard care with standard care alone. The Cortexin group reported larger gains in thinking scores, anxiety, depression and numbness.[5]
  • Depression: in a 2026 study of 98 adults taking antidepressants, the 48 who also got 10 days of Cortexin shots had larger drops in depression scores at four weeks and fewer side effects than those on antidepressants alone. There was no placebo, and one author wrote the report.[11]
  • Children: a 2018 Russian study gave a course of 10 shots to 635 children aged 3 to 7 with attention deficit hyperactivity disorder (ADHD), speech delay or other problems. Attention, memory and thinking tests improved, most in 3 and 4 year olds with ADHD, but there was no comparison group.[10]
  • Sleep: a pilot study of 50 adults with poor sleep and reduced blood flow to the brain reported fewer complaints and less anxiety and depression after 10 days of shots into a muscle, still present a month later. There was no comparison group.[12]
  • Healthy volunteers: a Russian study in people aged 20 to 24 found Cortexin helped them cope only with low oxygen, not with cold or heat.[13]
  • A 2021 systematic review of animal derived brain drugs found only one Cortexin trial, with 80 people, that met its standards. It suggested possible benefit but rated the evidence low to very low certainty.[6]

Limit: Most trials were open label, compared Cortexin with usual care and were run in Russia, so it is hard to tell real effects from expectation.

Claims check

The most common claims about this compound, and what studies actually found. Verdicts rate the evidence, not whether you should use it.

Improves memory and thinking

Mixed results

Russian trials in 189 adults with reduced brain blood flow and 110 adults with diabetes reported better thinking scores, but both compared Cortexin with usual care, not placebo.[4][5] An independent 2021 review found only one qualifying trial of 80 people and rated the evidence low to very low certainty.[6]

Speeds recovery after stroke

Mixed results

A 272 patient placebo controlled trial reported better results with two courses, but published no numbers in its summary.[7] Cochrane rated that trial's bias risk unclear and found that brain extracts probably do not change the chance of dying after stroke.[8] A 490 person trial compared two routes and had no placebo only group.[9]

Helps children with ADHD and speech delay

Mixed results

In 635 children aged 3 to 7, attention, memory and thinking tests improved after a course of shots, but there was no untreated or placebo group, and children improve with age and time.[10] No placebo controlled trial in children was found.

Eases anxiety and depression

Mixed results

In 98 adults on antidepressants, adding Cortexin was linked to larger drops in depression scores at four weeks, without a placebo.[11] In the 189 person trial, mood and anxiety effects were small and appeared only after repeated courses.[4] The diabetes trial also reported less anxiety and depression versus usual care.[5]

Improves sleep

Mixed results

The 189 person trial reported better sleep with Cortexin than usual care.[4] A pilot study of 50 adults with sleep problems reported improvement but had no comparison group.[12] No placebo controlled sleep trial has been published.

Protects and repairs brain cells

Only in animals

In rats, Cortexin shrank stroke damage, raised antioxidant defenses and left more healthy nerve cells after brain injury in newborns.[1][3] Direct protection of brain cells has not been measured in people.

Known risks and side effects

  • Side effects in trials. In the 490 person stroke trial, 60 of 246 people (about 1 in 4) in the vein group and 41 of 244 in the muscle group had side effects, with no clear difference between routes.[9] In the diabetes trial, five side effects were reported and none were judged related to treatment.[5]
  • Unproven benefit. Most published trials compared Cortexin with usual care rather than a placebo, and independent reviewers rate the evidence as weak.[8][6]
  • Animal brain source. It is a blend of many peptides from cattle and pig brain rather than one defined molecule.[1]
  • Industry funded research. Key animal work was funded by a drug company, and three of the authors were company employees.[1]
  • Unregulated imports. Cortexin has no US approval or drug label, so products bought online have not been checked by FDA for quality, sterility or authenticity.[2]

Regulatory status

Today: Cortexin is not approved by FDA and has no US drug label.[2] It is not on FDA's May 2026 compounding nomination list.[14] Extracts of this kind, including Cortexin, are used in Russia and other former Soviet countries.[1] WADA's 2026 list does not name it.[15]

  1. A Cochrane review added a Cortexin stroke trial and concluded that brain extracts of this type probably do not reduce deaths after stroke.[8]

Sources

  1. Kurkin DV, Bakulin DA, Morkovin EI, et al. Neuroprotective action of Cortexin, Cerebrolysin and Actovegin in acute or chronic brain ischemia in rats. PLoS One. 2021;16(7):e0254493. PMID 34260655
  2. DailyMed. Search results for cortexin. U.S. National Library of Medicine. Searched October 2026; 0 results. DailyMed
  3. Kurkin DV, et al. Neurotropic Effects of Cortexin on Models of Mental and Physical Developmental Delay. Biomedicines. 2025;13(4):860. PMID 40299434
  4. Fedin AI, Belskaya GN, Kurushina OV, Kovalchuk VV, Starych EV, Chichanovskaya LV, Baranova OA. Dose-dependent effects of cortexin in chronic cerebral ischemia (results of a multicenter randomized controlled study). Zh Nevrol Psikhiatr Im S S Korsakova. 2018;118(9):35-42. PMID 30335070
  5. Cortexin in the comprehensive treatment of neurological complications of type 2 diabetes mellitus (results of the DIACORT multicenter randomized clinical trial). Zh Nevrol Psikhiatr Im S S Korsakova. 2026;126(4):101-112. PMID 42133422
  6. Alsulaimani RA, Quinn TJ. The efficacy and safety of animal-derived nootropics in cognitive disorders: Systematic review and meta-analysis. Cereb Circ Cogn Behav. 2021;2:100012. PMID 36324709
  7. Aliferova VM, Dadasheva MN, Doronin BM, Kovalenko AV, Lokshtanova TM, Martynov MIu, et al. Clinical efficacy and pharmacoeconomic characteristics of the neuroprotection with low doses of cortexin in the treatment of acute ischemic stroke. Zh Nevrol Psikhiatr Im S S Korsakova. 2014;114(4):41-46. PMID 24874316
  8. Ziganshina LE, Abakumova T, Nurkhametova D, Ivanchenko K. Cerebrolysin for acute ischaemic stroke. Cochrane Database Syst Rev. 2023;10(10):CD007026. PMID 37818733
  9. Fedin AI, Khairova EN, Artyukov OP, Timchenko LV, Bazhenova OA, Gaiduk NV, Zykov MV. Therapeutic equivalence of intravenous and intramuscular dosage forms of Cortexin in ischemic strokes. Zh Nevrol Psikhiatr Im S S Korsakova. 2025;125(12):60-67. PMID 41524350
  10. Zykov VP, Serebrennikova EB, Panchenko TN, Sycheva YaB, Presnyakova SN, Mazur EL, et al. Results of a multicenter study on the efficacy of cortexin in treatment of cognitive dysfunction in children. Zh Nevrol Psikhiatr Im S S Korsakova. 2018;118(3):27-31. PMID 29652302
  11. Schastnyy ED. Efficacy and safety of Cortexin as additional therapy in patients with depressive disorder. Zh Nevrol Psikhiatr Im S S Korsakova. 2026;126(2):92-96. PMID 41782536
  12. Putilina MV, Shabalina NI. Results of a pilot study of the structure and evaluation of the therapy for chronic sleep disorders in comorbid patients with chronic cerebral ischemia. Zh Nevrol Psikhiatr Im S S Korsakova. 2024;124(4):118-126. PMID 38676686
  13. Shabanov PD, Ganapol'skiĭ VP, Aleksandrov PV. Meteoadaptogenic properties of peptide drugs in healthy volunteers. Eksp Klin Farmakol. 2007;70(6):41-47. PMID 18318195
  14. U.S. Food and Drug Administration. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the FD&C Act (category lists). Updated May 14, 2026. FDA category list
  15. World Anti-Doping Agency. World Anti-Doping Code International Standard: Prohibited List 2026. In force January 1, 2026. WADA 2026 List
Medical disclaimer

This page is educational information only. It is not medical advice and does not replace care from a licensed medical provider. Do not use this page to decide whether to take any substance. Talk to a licensed medical provider first.

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