Cortagen

updated

Cortagen is the synthetic tetrapeptide Ala-Glu-Asp-Pro from the Khavinson group of Russian short-peptide bioregulators, sold for stress resilience, learning and memory. No controlled human study exists. Its best animal result is faster sciatic nerve regeneration in rats, the nearest thing to a behavior result is recovery after brain ischemia in rats, and no study tested learning, memory or stress resilience. It was made from an analysis of Cortexin, a different brain extract product whose results do not apply to the peptide.

Synthetic tetrapeptide bioregulator

  • PubChem lists Cortagen as CID 18439621, C17H26N4O9, molecular weight 430.4, CAS 335591-03-2, Ala-Glu-Asp-Pro. It also appears as cortagene and, in the group's 2022 table, as Korthagen.
  • In rats with sciatic nerve transection and suturing, intramuscular cortagen at 10 microg/kg for 10 days increased the growth rate of regenerating fibers by 27% and conduction velocity by 40%.
  • In rats with chronic brain ischemia, Cortexin and cortagen each accelerated recovery of disturbed behavior; the abstract names no learning, memory or stress test, and no dose or route.
  • In 6-month-old mice, 5 days of cortagen injections changed 234 clones (1.53%) on a 15,247-transcript heart microarray, a gene-expression screen in a non-target organ.
  • Cortagen was weaker than or no different from comparison peptides in mouse thymocytes, mouse splenocytes and hypophysectomized birds.
  • A PubMed search on 10 October 2026 for cortagen returned 15 records; restricting it to clinical trial or randomized controlled trial publication types returned 0.

What is Cortagen, and is it an approved drug?

Cortagen is the synthetic tetrapeptide Ala-Glu-Asp-Pro (AEDP) from the Khavinson group, made from an analysis of Cortexin, a different brain extract product. openFDA Drugs@FDA and DailyMed return no product under the name, so no FDA record of it was found.

PubChem lists Cortagen as CID 18439621, C17H26N4O9, molecular weight 430.4, CAS 335591-03-2, with a systematic name that reads Ala-Glu-Asp-Pro. The same sequence appears in the group's abstracts from 2002, 2004, 2008 and 2023, so the sequence is consistent in print. Older papers also spell the name cortagene, and the group's 2022 table of ultrashort peptides writes it Korthagen (AEDP), so search under all three spellings to find the older work.

A 2004 abstract says Cortagen was obtained by directed synthesis from an amino acid analysis of Cortexin, a natural brain cortex peptide preparation. A 2002 report tested Cortexin and Cortagen as separate preparations in rat explants of cerebral cortex, and a 2001 report calls Cortagen a synthetic cytogen. Cortexin is a different product, a mixture extracted from animal brain, and it has its own evidence record; nothing in a Cortexin study applies to the tetrapeptide.

On 10 October 2026 openFDA Drugs@FDA and DailyMed returned no product under the name Cortagen. That covers FDA sources and says nothing about other regulators.

PubChem: Cortagen identity

Chemical identity record

National Library of Medicine. PubChem compound record CID 18439621.

PubChem lists Cortagen as CID 18439621, C17H26N4O9, molecular weight 430.4, CAS 335591-03-2, with a systematic name that reads Ala-Glu-Asp-Pro. The same sequence appears in the group's abstracts from 2002, 2004, 2008 and 2023, so the sequence is consistent in print.

Participants / model
Chemical identity, not a clinical population
Treatment
Defined synthetic peptide
Follow-up
Not applicable
Study design
NLM chemical record
Funding
not stated in the source

A defined tetrapeptide record.

Read the original source
2004 microarray: 234 of 15,247 heart transcripts changed in mice

Animal study

Anisimov SV et al. Neuro Endocrinol Lett. 2004;25(1-2):87-93. PMID 15159690.

A 2004 abstract says Cortagen was obtained by directed synthesis from an amino acid analysis of Cortexin, a natural brain cortex peptide preparation. Female 6-month-old CBA mice received cortagen injections for 5 consecutive days, and heart tissue was analyzed with a microarray covering 15,247 transcripts. A total of 234 clones (1.53%) changed significantly, matching 110 known genes. The abstract compares the profile with Vilon, Epithalon and melatonin and reports both shared and Cortagen-specific effects. The abstract also contains a statement about a human effect on recovery of peripheral nerve tissue; no PubMed record found describes that human work.

Participants / model
Female 6-month-old CBA mice
Treatment
Injections for 5 consecutive days; dose and route not stated in the abstract
Follow-up
5 consecutive days
Study design
Gene-expression microarray screen in heart tissue
Funding
not stated in the source

A gene-expression screen in a non-target organ. Cortexin is a different product, a mixture extracted from animal brain, and nothing in a Cortexin study applies to the tetrapeptide.

Read the original source
PubMed: 15 records, no clinical trial, no learning or stress test

PubMed search record

PubMed searches run 10 October 2026: cortagen; cortagen restricted to clinical trial or randomized controlled trial publication types; cortagen AND (learning OR memory OR cognitive OR stress OR anxiety OR behavior); cortagen AND (patients OR humans OR clinical). openFDA Drugs@FDA and DailyMed queries, run the same day.

A PubMed search for cortagen returned 15 records, all from Russian or Georgian research groups with Khavinson as an author on 9, and cortagen restricted to clinical trial or randomized controlled trial publication types returned 0 records. A search for cortagen AND (learning OR memory OR cognitive OR stress OR anxiety OR behavior) returned 2 records: the ischemic rat behavior study and a 2016 abstract that does not name cortagen; neither tests learning, memory or stress resilience. A search for cortagen AND (patients OR humans OR clinical) returned 3 records, none a human treatment study: the mouse heart microarray, the leukocyte chromatin paper and the 2023 lymphocyte paper. openFDA Drugs@FDA and DailyMed return no product under the name. The group's own 2022 table gives the stress protector label to Chonluten (EDG) and lists Korthagen (AEDP) only as a neuroprotector. The searches found no human dose, no human pharmacokinetics, no human safety data, and no learning, memory or stress test of any kind.

Participants / model
Records reviewed, not a population
Treatment
Not applicable
Follow-up
Search run on 10 October 2026
Study design
Dated literature and registry search
Funding
not stated in the source

An absence finding as of 10 October 2026, not proof that no unpublished work exists.

Read the original source

What did the animal and cell studies find?

The best-defined result is in nerve repair: in rats with a cut sciatic nerve, intramuscular cortagen at 10 microg/kg for 10 days raised the growth rate of regenerating fibers by 27% and conduction velocity by 40%. In rats with chronic brain ischemia it accelerated recovery of disturbed behavior. In mouse cells and hypophysectomized birds it was weaker than or no different from comparison peptides.

In rats, intramuscular cortagen at 10 microg/kg for 10 days after transection and suturing of the sciatic nerve increased the growth rate of regenerating fibers by 27% and conduction velocity by 40%. A 2002 follow-up on the delayed effect of cortagen on injured nerve function has overlapping authors and no abstract in PubMed. This is nerve repair, not cognition.

In rats with chronic brain ischemia and different resistance to hypoxia, the polypeptide extract Cortexin and the synthetic peptide drug cortagen each accelerated recovery of disturbed individual behavior and prevented excessive lipid peroxidation and loss of antioxidant activity in brain tissue. The abstract names no learning or memory test, no stress test, no dose and no route. A related 2007 abstract found that cortagen and epithalon injections in rats lowered lipid peroxidation products in serum and cerebral cortex.

Female 6-month-old CBA mice received cortagen injections for 5 consecutive days, and heart tissue was analyzed with a microarray covering 15,247 transcripts. A total of 234 clones (1.53%) changed significantly, matching 110 known genes. The abstract compares the profile with Vilon, Epithalon and melatonin and reports both shared and Cortagen-specific effects. This is a gene-expression screen in a non-target organ, and the abstract gives no dose or route.

Negative and weaker results also exist. In mouse thymocytes, Cortagen produced no comitogenic effect, while Vilon was the most potent and Epithalon weaker. In mouse splenocytes, Cortagen produced a less pronounced effect on interleukin-2 mRNA than Vilon or Epithalon. In neonatally hypophysectomized chicks and old birds, epithalon injections eliminated shifts in erythrocytes, immunity and hemostasis, while injections of cortagene for 40 days, which differs from epithalon only in the last residue (Pro instead of Gly), did not affect the parameters studied.

Rat sciatic nerve: fiber growth rate +27%, conduction velocity +40%

Animal study

Turchaninova LN et al. Bull Exp Biol Med. 2000;130(12):1172-4. PMID 11276314.

In rats, intramuscular cortagen at 10 microg/kg for 10 days after transection and suturing of the sciatic nerve increased the growth rate of regenerating fibers by 27% and conduction velocity by 40%. A 2002 follow-up on the delayed effect of cortagen on injured nerve function has overlapping authors and no abstract in PubMed.

Participants / model
Rats with sciatic nerve transection and suturing
Treatment
Intramuscular injection, 10 microg/kg for 10 days
Follow-up
10 days
Study design
Preclinical nerve regeneration model
Funding
not stated in the source

The best-defined animal result, in nerve repair and not in cognition.

Read the original source
Rat brain ischemia: recovery of disturbed behavior, lipid peroxidation

Animal study

Zarubina IV et al. Eksp Klin Farmakol. 2011;74(2):8-15. PMID 21476278.

In rats with chronic brain ischemia and different resistance to hypoxia, the polypeptide extract Cortexin and the synthetic peptide drug cortagen each accelerated recovery of disturbed individual behavior and prevented excessive lipid peroxidation and loss of antioxidant activity in brain tissue. The abstract names no learning or memory test, no stress test, no dose, and no route. A related 2007 abstract found that cortagen and epithalon injections in rats lowered lipid peroxidation products in serum and cerebral cortex.

Participants / model
Rats with chronic cerebral ischemia
Treatment
Cortagen as dosed in the report; dose and route not stated in the abstract
Follow-up
not stated in the source
Study design
Preclinical ischemia model, Russian-language report
Funding
not stated in the source

The nearest thing to a behavior result. It measures recovery after ischemia, not learning, memory or stress resilience.

Read the original source
2004 microarray: 234 of 15,247 heart transcripts changed in mice

Animal study

Anisimov SV et al. Neuro Endocrinol Lett. 2004;25(1-2):87-93. PMID 15159690.

A 2004 abstract says Cortagen was obtained by directed synthesis from an amino acid analysis of Cortexin, a natural brain cortex peptide preparation. Female 6-month-old CBA mice received cortagen injections for 5 consecutive days, and heart tissue was analyzed with a microarray covering 15,247 transcripts. A total of 234 clones (1.53%) changed significantly, matching 110 known genes. The abstract compares the profile with Vilon, Epithalon and melatonin and reports both shared and Cortagen-specific effects. The abstract also contains a statement about a human effect on recovery of peripheral nerve tissue; no PubMed record found describes that human work.

Participants / model
Female 6-month-old CBA mice
Treatment
Injections for 5 consecutive days; dose and route not stated in the abstract
Follow-up
5 consecutive days
Study design
Gene-expression microarray screen in heart tissue
Funding
not stated in the source

A gene-expression screen in a non-target organ. Cortexin is a different product, a mixture extracted from animal brain, and nothing in a Cortexin study applies to the tetrapeptide.

Read the original source
Weaker or null results: mouse thymocytes, splenocytes, hypophysectomized birds

Animal study

Kuznik BI et al. Adv Gerontol. 2008;21(3):372-81. PMID 19432169.

In mouse thymocytes, Cortagen produced no comitogenic effect, while Vilon was the most potent and Epithalon weaker. In mouse splenocytes, Cortagen produced a less pronounced effect on interleukin-2 mRNA than Vilon or Epithalon. In neonatally hypophysectomized chicks and old birds, epithalon injections eliminated shifts in erythrocytes, immunity and hemostasis, while injections of cortagene, which differs from epithalon only in the last residue (Pro instead of Gly), did not affect the parameters studied.

Participants / model
Mouse thymocytes and splenocytes; hypophysectomized chicks and old birds
Treatment
Peptides in vitro; injections in birds for 40 days; doses and routes not given
Follow-up
40 days in birds
Study design
Comparative cell and bird experiments
Funding
not stated in the source

Negative and weaker results for Cortagen against comparison peptides. The name appears here as cortagene.

Read the original source

Has Cortagen been tested in people?

No treatment study in people was found. A PubMed search on 10 October 2026 for cortagen returned 15 records, and restricting it to clinical trial or randomized controlled trial publication types returned 0. The human work is cultured blood cells from people aged 75 to 88, measuring chromatin and chromosomes, not a health outcome.

A PubMed search for cortagen returned 15 records, all from Russian or Georgian research groups, with Khavinson as an author on 9. A search for cortagen AND (patients OR humans OR clinical) returned 3 records, none a human treatment study: the mouse heart microarray, the leukocyte chromatin paper and the 2023 lymphocyte paper.

The group's 2004 report studied Vilon, Epithalon, Livagen, Prostamax and Cortagen in leukocytes from subjects aged 75 to 88 and reports that all the peptides activated ribosomal genes and decondensed chromatin. A 2023 paper using lymphocyte culture from people aged 75 to 88 reports that each peptide had a selective effect on chromosome regions. The abstracts describe chromatin and chromosome measures in cultured cells, not a health outcome in a person.

One 2004 abstract also states a human effect on recovery of injured peripheral nerve tissue. No PubMed record found describes that human work, so this page does not treat it as a finding. Across the searches there is no human dose, no human pharmacokinetics, no human safety data and no learning, memory or stress test of any kind.

PubMed: 15 records, no clinical trial, no learning or stress test

PubMed search record

PubMed searches run 10 October 2026: cortagen; cortagen restricted to clinical trial or randomized controlled trial publication types; cortagen AND (learning OR memory OR cognitive OR stress OR anxiety OR behavior); cortagen AND (patients OR humans OR clinical). openFDA Drugs@FDA and DailyMed queries, run the same day.

A PubMed search for cortagen returned 15 records, all from Russian or Georgian research groups with Khavinson as an author on 9, and cortagen restricted to clinical trial or randomized controlled trial publication types returned 0 records. A search for cortagen AND (learning OR memory OR cognitive OR stress OR anxiety OR behavior) returned 2 records: the ischemic rat behavior study and a 2016 abstract that does not name cortagen; neither tests learning, memory or stress resilience. A search for cortagen AND (patients OR humans OR clinical) returned 3 records, none a human treatment study: the mouse heart microarray, the leukocyte chromatin paper and the 2023 lymphocyte paper. openFDA Drugs@FDA and DailyMed return no product under the name. The group's own 2022 table gives the stress protector label to Chonluten (EDG) and lists Korthagen (AEDP) only as a neuroprotector. The searches found no human dose, no human pharmacokinetics, no human safety data, and no learning, memory or stress test of any kind.

Participants / model
Records reviewed, not a population
Treatment
Not applicable
Follow-up
Search run on 10 October 2026
Study design
Dated literature and registry search
Funding
not stated in the source

An absence finding as of 10 October 2026, not proof that no unpublished work exists.

Read the original source
Human blood cells from people aged 75 to 88: chromatin and chromosome measures

Cell study

Khavinson VKh et al. Bull Exp Biol Med. 2004;137(1):78-81. PMID 15085253.

The group's 2004 report studied Vilon, Epithalon, Livagen, Prostamax and Cortagen in leukocytes from subjects aged 75 to 88 and reports that all the peptides activated ribosomal genes and decondensed chromatin. A 2023 paper using lymphocyte culture from people aged 75 to 88 reports that each peptide had a selective effect on chromosome regions. The abstracts describe chromatin and chromosome measures in cultured cells, not a health outcome in a person.

Participants / model
Lymphocytes or leukocytes from people aged 75 to 88
Treatment
Peptides in cell culture
Follow-up
not stated in the source
Study design
Cell-culture chromatin and chromosome study
Funding
not stated in the source

Human cells, with no human treatment.

Read the original source
2004 microarray: 234 of 15,247 heart transcripts changed in mice

Animal study

Anisimov SV et al. Neuro Endocrinol Lett. 2004;25(1-2):87-93. PMID 15159690.

A 2004 abstract says Cortagen was obtained by directed synthesis from an amino acid analysis of Cortexin, a natural brain cortex peptide preparation. Female 6-month-old CBA mice received cortagen injections for 5 consecutive days, and heart tissue was analyzed with a microarray covering 15,247 transcripts. A total of 234 clones (1.53%) changed significantly, matching 110 known genes. The abstract compares the profile with Vilon, Epithalon and melatonin and reports both shared and Cortagen-specific effects. The abstract also contains a statement about a human effect on recovery of peripheral nerve tissue; no PubMed record found describes that human work.

Participants / model
Female 6-month-old CBA mice
Treatment
Injections for 5 consecutive days; dose and route not stated in the abstract
Follow-up
5 consecutive days
Study design
Gene-expression microarray screen in heart tissue
Funding
not stated in the source

A gene-expression screen in a non-target organ. Cortexin is a different product, a mixture extracted from animal brain, and nothing in a Cortexin study applies to the tetrapeptide.

Read the original source

Does Cortagen improve stress resilience, learning or memory?

No study tested it. The only behavior paper measured recovery after brain ischemia in rats and names no cognitive test, and the group's own 2022 table gives the stress-protector label to a different peptide and lists this one only as a neuroprotector. The supportable statement is faster sciatic nerve regeneration and recovery measures after brain ischemia, both in rats.

Sellers promote Cortagen for stress resilience, learning and memory. A PubMed search for cortagen AND (learning OR memory OR cognitive OR stress OR anxiety OR behavior) returned 2 records: the ischemic rat behavior study and a 2016 abstract that does not name cortagen. Neither tests learning, memory or stress resilience.

The group's own 2022 table gives the stress protector label to Chonluten (EDG) and lists Korthagen (AEDP), its spelling for this peptide, only as a neuroprotector.

The supportable statement is that cortagen sped sciatic nerve regeneration in rats and improved recovery measures after brain ischemia in rats. Neither is the use being sold, and results for Cortexin belong to Cortexin, not to this tetrapeptide.

Rat brain ischemia: recovery of disturbed behavior, lipid peroxidation

Animal study

Zarubina IV et al. Eksp Klin Farmakol. 2011;74(2):8-15. PMID 21476278.

In rats with chronic brain ischemia and different resistance to hypoxia, the polypeptide extract Cortexin and the synthetic peptide drug cortagen each accelerated recovery of disturbed individual behavior and prevented excessive lipid peroxidation and loss of antioxidant activity in brain tissue. The abstract names no learning or memory test, no stress test, no dose, and no route. A related 2007 abstract found that cortagen and epithalon injections in rats lowered lipid peroxidation products in serum and cerebral cortex.

Participants / model
Rats with chronic cerebral ischemia
Treatment
Cortagen as dosed in the report; dose and route not stated in the abstract
Follow-up
not stated in the source
Study design
Preclinical ischemia model, Russian-language report
Funding
not stated in the source

The nearest thing to a behavior result. It measures recovery after ischemia, not learning, memory or stress resilience.

Read the original source
Rat sciatic nerve: fiber growth rate +27%, conduction velocity +40%

Animal study

Turchaninova LN et al. Bull Exp Biol Med. 2000;130(12):1172-4. PMID 11276314.

In rats, intramuscular cortagen at 10 microg/kg for 10 days after transection and suturing of the sciatic nerve increased the growth rate of regenerating fibers by 27% and conduction velocity by 40%. A 2002 follow-up on the delayed effect of cortagen on injured nerve function has overlapping authors and no abstract in PubMed.

Participants / model
Rats with sciatic nerve transection and suturing
Treatment
Intramuscular injection, 10 microg/kg for 10 days
Follow-up
10 days
Study design
Preclinical nerve regeneration model
Funding
not stated in the source

The best-defined animal result, in nerve repair and not in cognition.

Read the original source
PubMed: 15 records, no clinical trial, no learning or stress test

PubMed search record

PubMed searches run 10 October 2026: cortagen; cortagen restricted to clinical trial or randomized controlled trial publication types; cortagen AND (learning OR memory OR cognitive OR stress OR anxiety OR behavior); cortagen AND (patients OR humans OR clinical). openFDA Drugs@FDA and DailyMed queries, run the same day.

A PubMed search for cortagen returned 15 records, all from Russian or Georgian research groups with Khavinson as an author on 9, and cortagen restricted to clinical trial or randomized controlled trial publication types returned 0 records. A search for cortagen AND (learning OR memory OR cognitive OR stress OR anxiety OR behavior) returned 2 records: the ischemic rat behavior study and a 2016 abstract that does not name cortagen; neither tests learning, memory or stress resilience. A search for cortagen AND (patients OR humans OR clinical) returned 3 records, none a human treatment study: the mouse heart microarray, the leukocyte chromatin paper and the 2023 lymphocyte paper. openFDA Drugs@FDA and DailyMed return no product under the name. The group's own 2022 table gives the stress protector label to Chonluten (EDG) and lists Korthagen (AEDP) only as a neuroprotector. The searches found no human dose, no human pharmacokinetics, no human safety data, and no learning, memory or stress test of any kind.

Participants / model
Records reviewed, not a population
Treatment
Not applicable
Follow-up
Search run on 10 October 2026
Study design
Dated literature and registry search
Funding
not stated in the source

An absence finding as of 10 October 2026, not proof that no unpublished work exists.

Read the original source

How is Cortagen thought to work?

No mechanism is established. In mice, 5 days of cortagen injections changed 234 clones (1.53%) on a 15,247-transcript heart microarray, matching 110 known genes, some shared with Vilon, Epithalon and melatonin. In rats with brain ischemia it prevented excessive lipid peroxidation and loss of antioxidant activity.

The mouse heart microarray covered 15,247 transcripts, and 234 clones (1.53%) changed significantly, matching 110 known genes. The abstract compares the profile with Vilon, Epithalon and melatonin and reports both shared and Cortagen-specific effects.

In rats with chronic brain ischemia, cortagen and Cortexin each prevented excessive lipid peroxidation and loss of antioxidant activity in brain tissue, and a related 2007 abstract found lowered lipid peroxidation products in serum and cerebral cortex after cortagen and epithalon injections. These are expression and oxidative stress measures, not a defined mechanism, and no pharmacokinetic data were found in any species.

2004 microarray: 234 of 15,247 heart transcripts changed in mice

Animal study

Anisimov SV et al. Neuro Endocrinol Lett. 2004;25(1-2):87-93. PMID 15159690.

A 2004 abstract says Cortagen was obtained by directed synthesis from an amino acid analysis of Cortexin, a natural brain cortex peptide preparation. Female 6-month-old CBA mice received cortagen injections for 5 consecutive days, and heart tissue was analyzed with a microarray covering 15,247 transcripts. A total of 234 clones (1.53%) changed significantly, matching 110 known genes. The abstract compares the profile with Vilon, Epithalon and melatonin and reports both shared and Cortagen-specific effects. The abstract also contains a statement about a human effect on recovery of peripheral nerve tissue; no PubMed record found describes that human work.

Participants / model
Female 6-month-old CBA mice
Treatment
Injections for 5 consecutive days; dose and route not stated in the abstract
Follow-up
5 consecutive days
Study design
Gene-expression microarray screen in heart tissue
Funding
not stated in the source

A gene-expression screen in a non-target organ. Cortexin is a different product, a mixture extracted from animal brain, and nothing in a Cortexin study applies to the tetrapeptide.

Read the original source
Rat brain ischemia: recovery of disturbed behavior, lipid peroxidation

Animal study

Zarubina IV et al. Eksp Klin Farmakol. 2011;74(2):8-15. PMID 21476278.

In rats with chronic brain ischemia and different resistance to hypoxia, the polypeptide extract Cortexin and the synthetic peptide drug cortagen each accelerated recovery of disturbed individual behavior and prevented excessive lipid peroxidation and loss of antioxidant activity in brain tissue. The abstract names no learning or memory test, no stress test, no dose, and no route. A related 2007 abstract found that cortagen and epithalon injections in rats lowered lipid peroxidation products in serum and cerebral cortex.

Participants / model
Rats with chronic cerebral ischemia
Treatment
Cortagen as dosed in the report; dose and route not stated in the abstract
Follow-up
not stated in the source
Study design
Preclinical ischemia model, Russian-language report
Funding
not stated in the source

The nearest thing to a behavior result. It measures recovery after ischemia, not learning, memory or stress resilience.

Read the original source

What is known about the safety of Cortagen?

No human safety data exist for Cortagen: no human dose, pharmacokinetics or treatment study was found. The only animal dose and route stated in an abstract is 10 microg/kg given intramuscularly to rats for 10 days.

A PubMed search on 10 October 2026 found no human treatment study of Cortagen, so there is no human dose, no human pharmacokinetics and no human safety data.

The only animal dose and route stated in an abstract is the rat sciatic nerve study, 10 microg/kg intramuscularly for 10 days. The mouse heart and rat brain ischemia abstracts give no dose or route, and none is given for the bird work.

PubMed: 15 records, no clinical trial, no learning or stress test

PubMed search record

PubMed searches run 10 October 2026: cortagen; cortagen restricted to clinical trial or randomized controlled trial publication types; cortagen AND (learning OR memory OR cognitive OR stress OR anxiety OR behavior); cortagen AND (patients OR humans OR clinical). openFDA Drugs@FDA and DailyMed queries, run the same day.

A PubMed search for cortagen returned 15 records, all from Russian or Georgian research groups with Khavinson as an author on 9, and cortagen restricted to clinical trial or randomized controlled trial publication types returned 0 records. A search for cortagen AND (learning OR memory OR cognitive OR stress OR anxiety OR behavior) returned 2 records: the ischemic rat behavior study and a 2016 abstract that does not name cortagen; neither tests learning, memory or stress resilience. A search for cortagen AND (patients OR humans OR clinical) returned 3 records, none a human treatment study: the mouse heart microarray, the leukocyte chromatin paper and the 2023 lymphocyte paper. openFDA Drugs@FDA and DailyMed return no product under the name. The group's own 2022 table gives the stress protector label to Chonluten (EDG) and lists Korthagen (AEDP) only as a neuroprotector. The searches found no human dose, no human pharmacokinetics, no human safety data, and no learning, memory or stress test of any kind.

Participants / model
Records reviewed, not a population
Treatment
Not applicable
Follow-up
Search run on 10 October 2026
Study design
Dated literature and registry search
Funding
not stated in the source

An absence finding as of 10 October 2026, not proof that no unpublished work exists.

Read the original source
Rat sciatic nerve: fiber growth rate +27%, conduction velocity +40%

Animal study

Turchaninova LN et al. Bull Exp Biol Med. 2000;130(12):1172-4. PMID 11276314.

In rats, intramuscular cortagen at 10 microg/kg for 10 days after transection and suturing of the sciatic nerve increased the growth rate of regenerating fibers by 27% and conduction velocity by 40%. A 2002 follow-up on the delayed effect of cortagen on injured nerve function has overlapping authors and no abstract in PubMed.

Participants / model
Rats with sciatic nerve transection and suturing
Treatment
Intramuscular injection, 10 microg/kg for 10 days
Follow-up
10 days
Study design
Preclinical nerve regeneration model
Funding
not stated in the source

The best-defined animal result, in nerve repair and not in cognition.

Read the original source
2004 microarray: 234 of 15,247 heart transcripts changed in mice

Animal study

Anisimov SV et al. Neuro Endocrinol Lett. 2004;25(1-2):87-93. PMID 15159690.

A 2004 abstract says Cortagen was obtained by directed synthesis from an amino acid analysis of Cortexin, a natural brain cortex peptide preparation. Female 6-month-old CBA mice received cortagen injections for 5 consecutive days, and heart tissue was analyzed with a microarray covering 15,247 transcripts. A total of 234 clones (1.53%) changed significantly, matching 110 known genes. The abstract compares the profile with Vilon, Epithalon and melatonin and reports both shared and Cortagen-specific effects. The abstract also contains a statement about a human effect on recovery of peripheral nerve tissue; no PubMed record found describes that human work.

Participants / model
Female 6-month-old CBA mice
Treatment
Injections for 5 consecutive days; dose and route not stated in the abstract
Follow-up
5 consecutive days
Study design
Gene-expression microarray screen in heart tissue
Funding
not stated in the source

A gene-expression screen in a non-target organ. Cortexin is a different product, a mixture extracted from animal brain, and nothing in a Cortexin study applies to the tetrapeptide.

Read the original source
Rat brain ischemia: recovery of disturbed behavior, lipid peroxidation

Animal study

Zarubina IV et al. Eksp Klin Farmakol. 2011;74(2):8-15. PMID 21476278.

In rats with chronic brain ischemia and different resistance to hypoxia, the polypeptide extract Cortexin and the synthetic peptide drug cortagen each accelerated recovery of disturbed individual behavior and prevented excessive lipid peroxidation and loss of antioxidant activity in brain tissue. The abstract names no learning or memory test, no stress test, no dose, and no route. A related 2007 abstract found that cortagen and epithalon injections in rats lowered lipid peroxidation products in serum and cerebral cortex.

Participants / model
Rats with chronic cerebral ischemia
Treatment
Cortagen as dosed in the report; dose and route not stated in the abstract
Follow-up
not stated in the source
Study design
Preclinical ischemia model, Russian-language report
Funding
not stated in the source

The nearest thing to a behavior result. It measures recovery after ischemia, not learning, memory or stress resilience.

Read the original source

Why does Cortagen sit in C tier?

A defined tetrapeptide with a rat nerve regeneration result, a rat brain ischemia behavior study, a mouse gene-expression screen and several cell studies forms a coherent preclinical profile. There is no human treatment study and no pharmacokinetics, and the nerve result is not the use being sold.

Cortagen has rat nerve regeneration, a rat brain ischemia behavior study, a mouse gene-expression screen and several cell studies, including three where it was weaker than or no different from comparison peptides.

There is no human treatment study and no pharmacokinetics. Stress resilience and learning and memory have no study: the group's own table gives the stress-protector label to a different peptide, and the only behavior paper measured recovery after brain ischemia in rats.

Rat sciatic nerve: fiber growth rate +27%, conduction velocity +40%

Animal study

Turchaninova LN et al. Bull Exp Biol Med. 2000;130(12):1172-4. PMID 11276314.

In rats, intramuscular cortagen at 10 microg/kg for 10 days after transection and suturing of the sciatic nerve increased the growth rate of regenerating fibers by 27% and conduction velocity by 40%. A 2002 follow-up on the delayed effect of cortagen on injured nerve function has overlapping authors and no abstract in PubMed.

Participants / model
Rats with sciatic nerve transection and suturing
Treatment
Intramuscular injection, 10 microg/kg for 10 days
Follow-up
10 days
Study design
Preclinical nerve regeneration model
Funding
not stated in the source

The best-defined animal result, in nerve repair and not in cognition.

Read the original source
Rat brain ischemia: recovery of disturbed behavior, lipid peroxidation

Animal study

Zarubina IV et al. Eksp Klin Farmakol. 2011;74(2):8-15. PMID 21476278.

In rats with chronic brain ischemia and different resistance to hypoxia, the polypeptide extract Cortexin and the synthetic peptide drug cortagen each accelerated recovery of disturbed individual behavior and prevented excessive lipid peroxidation and loss of antioxidant activity in brain tissue. The abstract names no learning or memory test, no stress test, no dose, and no route. A related 2007 abstract found that cortagen and epithalon injections in rats lowered lipid peroxidation products in serum and cerebral cortex.

Participants / model
Rats with chronic cerebral ischemia
Treatment
Cortagen as dosed in the report; dose and route not stated in the abstract
Follow-up
not stated in the source
Study design
Preclinical ischemia model, Russian-language report
Funding
not stated in the source

The nearest thing to a behavior result. It measures recovery after ischemia, not learning, memory or stress resilience.

Read the original source
2004 microarray: 234 of 15,247 heart transcripts changed in mice

Animal study

Anisimov SV et al. Neuro Endocrinol Lett. 2004;25(1-2):87-93. PMID 15159690.

A 2004 abstract says Cortagen was obtained by directed synthesis from an amino acid analysis of Cortexin, a natural brain cortex peptide preparation. Female 6-month-old CBA mice received cortagen injections for 5 consecutive days, and heart tissue was analyzed with a microarray covering 15,247 transcripts. A total of 234 clones (1.53%) changed significantly, matching 110 known genes. The abstract compares the profile with Vilon, Epithalon and melatonin and reports both shared and Cortagen-specific effects. The abstract also contains a statement about a human effect on recovery of peripheral nerve tissue; no PubMed record found describes that human work.

Participants / model
Female 6-month-old CBA mice
Treatment
Injections for 5 consecutive days; dose and route not stated in the abstract
Follow-up
5 consecutive days
Study design
Gene-expression microarray screen in heart tissue
Funding
not stated in the source

A gene-expression screen in a non-target organ. Cortexin is a different product, a mixture extracted from animal brain, and nothing in a Cortexin study applies to the tetrapeptide.

Read the original source
Weaker or null results: mouse thymocytes, splenocytes, hypophysectomized birds

Animal study

Kuznik BI et al. Adv Gerontol. 2008;21(3):372-81. PMID 19432169.

In mouse thymocytes, Cortagen produced no comitogenic effect, while Vilon was the most potent and Epithalon weaker. In mouse splenocytes, Cortagen produced a less pronounced effect on interleukin-2 mRNA than Vilon or Epithalon. In neonatally hypophysectomized chicks and old birds, epithalon injections eliminated shifts in erythrocytes, immunity and hemostasis, while injections of cortagene, which differs from epithalon only in the last residue (Pro instead of Gly), did not affect the parameters studied.

Participants / model
Mouse thymocytes and splenocytes; hypophysectomized chicks and old birds
Treatment
Peptides in vitro; injections in birds for 40 days; doses and routes not given
Follow-up
40 days in birds
Study design
Comparative cell and bird experiments
Funding
not stated in the source

Negative and weaker results for Cortagen against comparison peptides. The name appears here as cortagene.

Read the original source
PubMed: 15 records, no clinical trial, no learning or stress test

PubMed search record

PubMed searches run 10 October 2026: cortagen; cortagen restricted to clinical trial or randomized controlled trial publication types; cortagen AND (learning OR memory OR cognitive OR stress OR anxiety OR behavior); cortagen AND (patients OR humans OR clinical). openFDA Drugs@FDA and DailyMed queries, run the same day.

A PubMed search for cortagen returned 15 records, all from Russian or Georgian research groups with Khavinson as an author on 9, and cortagen restricted to clinical trial or randomized controlled trial publication types returned 0 records. A search for cortagen AND (learning OR memory OR cognitive OR stress OR anxiety OR behavior) returned 2 records: the ischemic rat behavior study and a 2016 abstract that does not name cortagen; neither tests learning, memory or stress resilience. A search for cortagen AND (patients OR humans OR clinical) returned 3 records, none a human treatment study: the mouse heart microarray, the leukocyte chromatin paper and the 2023 lymphocyte paper. openFDA Drugs@FDA and DailyMed return no product under the name. The group's own 2022 table gives the stress protector label to Chonluten (EDG) and lists Korthagen (AEDP) only as a neuroprotector. The searches found no human dose, no human pharmacokinetics, no human safety data, and no learning, memory or stress test of any kind.

Participants / model
Records reviewed, not a population
Treatment
Not applicable
Follow-up
Search run on 10 October 2026
Study design
Dated literature and registry search
Funding
not stated in the source

An absence finding as of 10 October 2026, not proof that no unpublished work exists.

Read the original source

Studies and sources

PubChem: Cortagen identity

Chemical identity record

National Library of Medicine. PubChem compound record CID 18439621.

PubChem lists Cortagen as CID 18439621, C17H26N4O9, molecular weight 430.4, CAS 335591-03-2, with a systematic name that reads Ala-Glu-Asp-Pro. The same sequence appears in the group's abstracts from 2002, 2004, 2008 and 2023, so the sequence is consistent in print.

Participants / model
Chemical identity, not a clinical population
Treatment
Defined synthetic peptide
Follow-up
Not applicable
Study design
NLM chemical record
Funding
not stated in the source

A defined tetrapeptide record.

Read the original source
2004 microarray: 234 of 15,247 heart transcripts changed in mice

Animal study

Anisimov SV et al. Neuro Endocrinol Lett. 2004;25(1-2):87-93. PMID 15159690.

A 2004 abstract says Cortagen was obtained by directed synthesis from an amino acid analysis of Cortexin, a natural brain cortex peptide preparation. Female 6-month-old CBA mice received cortagen injections for 5 consecutive days, and heart tissue was analyzed with a microarray covering 15,247 transcripts. A total of 234 clones (1.53%) changed significantly, matching 110 known genes. The abstract compares the profile with Vilon, Epithalon and melatonin and reports both shared and Cortagen-specific effects. The abstract also contains a statement about a human effect on recovery of peripheral nerve tissue; no PubMed record found describes that human work.

Participants / model
Female 6-month-old CBA mice
Treatment
Injections for 5 consecutive days; dose and route not stated in the abstract
Follow-up
5 consecutive days
Study design
Gene-expression microarray screen in heart tissue
Funding
not stated in the source

A gene-expression screen in a non-target organ. Cortexin is a different product, a mixture extracted from animal brain, and nothing in a Cortexin study applies to the tetrapeptide.

Read the original source
Rat sciatic nerve: fiber growth rate +27%, conduction velocity +40%

Animal study

Turchaninova LN et al. Bull Exp Biol Med. 2000;130(12):1172-4. PMID 11276314.

In rats, intramuscular cortagen at 10 microg/kg for 10 days after transection and suturing of the sciatic nerve increased the growth rate of regenerating fibers by 27% and conduction velocity by 40%. A 2002 follow-up on the delayed effect of cortagen on injured nerve function has overlapping authors and no abstract in PubMed.

Participants / model
Rats with sciatic nerve transection and suturing
Treatment
Intramuscular injection, 10 microg/kg for 10 days
Follow-up
10 days
Study design
Preclinical nerve regeneration model
Funding
not stated in the source

The best-defined animal result, in nerve repair and not in cognition.

Read the original source
Rat brain ischemia: recovery of disturbed behavior, lipid peroxidation

Animal study

Zarubina IV et al. Eksp Klin Farmakol. 2011;74(2):8-15. PMID 21476278.

In rats with chronic brain ischemia and different resistance to hypoxia, the polypeptide extract Cortexin and the synthetic peptide drug cortagen each accelerated recovery of disturbed individual behavior and prevented excessive lipid peroxidation and loss of antioxidant activity in brain tissue. The abstract names no learning or memory test, no stress test, no dose, and no route. A related 2007 abstract found that cortagen and epithalon injections in rats lowered lipid peroxidation products in serum and cerebral cortex.

Participants / model
Rats with chronic cerebral ischemia
Treatment
Cortagen as dosed in the report; dose and route not stated in the abstract
Follow-up
not stated in the source
Study design
Preclinical ischemia model, Russian-language report
Funding
not stated in the source

The nearest thing to a behavior result. It measures recovery after ischemia, not learning, memory or stress resilience.

Read the original source
Weaker or null results: mouse thymocytes, splenocytes, hypophysectomized birds

Animal study

Kuznik BI et al. Adv Gerontol. 2008;21(3):372-81. PMID 19432169.

In mouse thymocytes, Cortagen produced no comitogenic effect, while Vilon was the most potent and Epithalon weaker. In mouse splenocytes, Cortagen produced a less pronounced effect on interleukin-2 mRNA than Vilon or Epithalon. In neonatally hypophysectomized chicks and old birds, epithalon injections eliminated shifts in erythrocytes, immunity and hemostasis, while injections of cortagene, which differs from epithalon only in the last residue (Pro instead of Gly), did not affect the parameters studied.

Participants / model
Mouse thymocytes and splenocytes; hypophysectomized chicks and old birds
Treatment
Peptides in vitro; injections in birds for 40 days; doses and routes not given
Follow-up
40 days in birds
Study design
Comparative cell and bird experiments
Funding
not stated in the source

Negative and weaker results for Cortagen against comparison peptides. The name appears here as cortagene.

Read the original source
Human blood cells from people aged 75 to 88: chromatin and chromosome measures

Cell study

Khavinson VKh et al. Bull Exp Biol Med. 2004;137(1):78-81. PMID 15085253.

The group's 2004 report studied Vilon, Epithalon, Livagen, Prostamax and Cortagen in leukocytes from subjects aged 75 to 88 and reports that all the peptides activated ribosomal genes and decondensed chromatin. A 2023 paper using lymphocyte culture from people aged 75 to 88 reports that each peptide had a selective effect on chromosome regions. The abstracts describe chromatin and chromosome measures in cultured cells, not a health outcome in a person.

Participants / model
Lymphocytes or leukocytes from people aged 75 to 88
Treatment
Peptides in cell culture
Follow-up
not stated in the source
Study design
Cell-culture chromatin and chromosome study
Funding
not stated in the source

Human cells, with no human treatment.

Read the original source
PubMed: 15 records, no clinical trial, no learning or stress test

PubMed search record

PubMed searches run 10 October 2026: cortagen; cortagen restricted to clinical trial or randomized controlled trial publication types; cortagen AND (learning OR memory OR cognitive OR stress OR anxiety OR behavior); cortagen AND (patients OR humans OR clinical). openFDA Drugs@FDA and DailyMed queries, run the same day.

A PubMed search for cortagen returned 15 records, all from Russian or Georgian research groups with Khavinson as an author on 9, and cortagen restricted to clinical trial or randomized controlled trial publication types returned 0 records. A search for cortagen AND (learning OR memory OR cognitive OR stress OR anxiety OR behavior) returned 2 records: the ischemic rat behavior study and a 2016 abstract that does not name cortagen; neither tests learning, memory or stress resilience. A search for cortagen AND (patients OR humans OR clinical) returned 3 records, none a human treatment study: the mouse heart microarray, the leukocyte chromatin paper and the 2023 lymphocyte paper. openFDA Drugs@FDA and DailyMed return no product under the name. The group's own 2022 table gives the stress protector label to Chonluten (EDG) and lists Korthagen (AEDP) only as a neuroprotector. The searches found no human dose, no human pharmacokinetics, no human safety data, and no learning, memory or stress test of any kind.

Participants / model
Records reviewed, not a population
Treatment
Not applicable
Follow-up
Search run on 10 October 2026
Study design
Dated literature and registry search
Funding
not stated in the source

An absence finding as of 10 October 2026, not proof that no unpublished work exists.

Read the original source

Why is Cortagen in C tier?

C fits a defined tetrapeptide with several animal and cell studies that add up to a coherent preclinical profile: rat nerve regeneration, a rat brain ischemia behavior study, a mouse gene-expression screen and cell work, including three results where it was weaker than comparison peptides. There is no human treatment study and no pharmacokinetics, and the nerve result is not the use being sold.