Cortagen

What it is

Cortagen belongs to the so-called bioregulators or cytogens, very short synthetic peptides that the Russian gerontologist Vladimir Khavinson and his colleagues have been developing for decades. The idea: the amino acid composition of an organ extract is determined, and from it a short peptide is built that is supposed to carry the effect of the extract in a targeted way.

For Cortagen, the model was Cortexin, a peptide complex from the cerebral cortex of animals that Russian pharmacologists use as a medicine. This is how a 2004 paper co-authored by Khavinson himself describes it. The sequence is Ala-Glu-Asp-Pro.

Distinction from Cortexin, Pinealon and Epitalon

The names are close together, the substances are not. Cortexin is not a single peptide but a mixture of cerebral cortex peptides that is injected and is approved in Russia. Cortagen is a single, chemically defined tetrapeptide that was derived from this mixture.

Pinealon is also associated with the brain, but is a different molecule: a tripeptide with the sequence Glu-Asp-Arg, EDR for short. Cortagen and Pinealon thus share neither length nor sequence, even though both are listed as neuro-bioregulators.

Chemically, Cortagen is most closely related to Epitalon. Epitalon is Ala-Glu-Asp-Gly, Cortagen Ala-Glu-Asp-Pro; they differ only in the last amino acid. That this small difference matters is shown by a 2008 experiment in chickens: there, Epitalon offset changes in blood, immune system and coagulation, Cortagen did not.

How it is supposed to work

The Khavinson school assumes that very short peptides enter the cell nucleus, bind there to DNA and histones and thus change the reading of certain genes. Each peptide is supposed to act preferentially in the tissue from whose extract it was derived. For Cortagen, that would be the cerebral cortex and, more broadly, nervous tissue.

Some laboratory findings fit this. In organ cultures of rat tissue, Cortagen stimulated the growth of cerebral cortex explants, tissue-specifically according to a 2001 paper. A 2020 review reports that AEDP can trigger the differentiation of progenitor cells into nervous tissue, among others. This is an internally consistent hypothesis with cell and animal findings. This chain of effects has not been measured in humans.

Signaling pathways of the immune system were also examined. In rats, Vilon, Epitalon and Cortagen changed the reading of the interleukin-2 gene in cells of the hypothalamus depending on timing and route of administration (2005). In macrophages of young and old mice, the same three peptides influenced the production of messengers that activate lymphocytes, with partly opposite effects in young and old animals (2006). Such findings show that the peptides are not biologically silent; what follows from this for the whole organism remains open.

What the studies show

Nerve regeneration in rats, 2000

Turchaninova and colleagues, including Khavinson, severed the sciatic nerve in rats and sutured it again. Under Cortagen over 10 days, the growth rate and conduction velocity of the regrowing fibers rose by 27 and 40 percent respectively. The publication is very brief; group sizes and control conditions are not evident from the abstract.

Gene activity in the mouse heart, 2004

Female mice aged 6 months received Cortagen for 5 days, after which the activity of 15,247 gene segments in the heart was measured. 234 clones, that is 1.53 percent, changed significantly, assigned to 110 known genes; the strongest increase is given as plus 5.42. The paper shows that Cortagen shifts gene activity, but says nothing about whether this benefits the animal.

Chromatin in blood cells of the very old, 2004 and 2023

A Georgian-Russian group led by Lezhava and Khavinson treated lymphocytes from donors between 75 and 88 years of age in cell culture with several short peptides. All loosened condensed chromatin and activated ribosomal genes; the 2023 paper sees a distinct pattern on the chromosomes for each peptide. These are human cells, but not an experiment in humans.

Chronic cerebral ischemia in rats, 2011

Zarubina and Shabanov compared Cortexin and Cortagen in rats with chronically reduced blood flow to the brain. Both accelerated behavioral recovery and prevented excessive lipid oxidation in brain tissue. The paper was published in Russian; only the abstract is available in English.

Where the data stop

There is no published controlled study in humans. The 2004 paper does state that Cortagen markedly promoted the recovery of injured peripheral nerves in humans, but cites no study with figures for this. PubMed lists 15 entries on Cortagen, almost all from Russian laboratories, most with Khavinson’s involvement, plus a Georgian cooperation; a search of ClinicalTrials.gov returns no study on Cortagen. Many original papers were published only in Russian and are very brief in their abstracts. This is not a lack of work, but a lack of accessibility and independent replication.

Not all findings point in the same direction. In the activation of thymus cells, Cortagen had no effect; in stimulating interleukin-2 in spleen cells it was weaker than Vilon and Epitalon; and in the chicken experiment, unlike Epitalon, it changed nothing. For the uses with which it is sold, that is, concentration, memory or protection against brain aging, there are no human data. Nor are there published measurements on whether Cortagen reaches the brain at all after injection or swallowing.

Status, approval and legal

In Germany and the EU, Cortagen is approved neither as a medicine nor as a food supplement; I also found no drug approval in the US. Unlike the parent preparation Cortexin, I found no evidence of a drug approval for Cortagen in Russia. In the West it is traded as a research peptide, without tested purity and not intended for humans. In sport, a non-approved substance falls under group S0 of the WADA Prohibited List and is prohibited at all times.

Safety

There are no systematic safety data in humans: no published toxicology to Western standards, no pharmacokinetics, no study recording side effects. The animal studies report no harm, but they were not designed to find any. Since Cortagen alters gene activity, the question of long-term consequences is justified and open. Added to this are the usual risks of gray-market peptides, that is, unclear purity, deviating content and contamination, and with injected products also infections. For pregnant and breastfeeding women, children and people with cancer there are no data whatsoever.

Sources

• Turchaninova et al., Bull Exp Biol Med 2000 – Cortagen and regeneration of the sciatic nerve
• Kolosova et al., Dokl Biol Sci 2002 – delayed effect on nerve function
• Anisimov, Khavinson, Anisimov, Neuro Endocrinol Lett 2004 – gene activity in the mouse heart
• Khavinson et al., Bull Exp Biol Med 2004 – chromatin in lymphocytes of the very old
• Lezhava et al., Georgian Med News 2023 – peptide bioregulators and aged chromatin
• Zarubina and Shabanov, Eksp Klin Farmakol 2011 – Cortexin and Cortagen in chronic cerebral ischemia
• Kozina, Bull Exp Biol Med 2007 – tetrapeptides and free radicals
• Kuznik et al., Adv Gerontol 2008 – Epitalon and Cortagen in chickens
• Khavinson, Bull Exp Biol Med 2001 – tissue-specific effect in organ culture
• Khavinson et al., Stem Cell Rev Rep 2020 – peptides and cell differentiation