Cortagen

Cortagen is a tetrapeptide, Ala-Glu-Asp-Pro (AEDP), assigned to the cerebral cortex within the Khavinson bioregulator series (Anisimov et al., Neuro Endocrinol Lett 2004). Evidence tier: minimal, though it is comparatively well documented at roughly fifteen PubMed records.

That relative richness is instructive rather than reassuring. Not one record is a controlled human trial, and the number most often quoted was measured in a peripheral nerve in rats — not in the cortex the peptide is named after.

• Organotypic explants. In rat tissue culture Cortagen stimulated outgrowth from brain-cortex explants while Epithalon acted on subcortical structures, Livagen on liver, and Vilon on thymus (Khavinson, Bull Exp Biol Med 2001). This is the whole empirical basis of the "tissue-specific" label.

• Peripheral nerve. Wistar rats given 10 µg/kg intramuscularly daily for ten days after sciatic nerve transection and suture showed a 27% faster fibre growth rate and 40% higher conduction velocity than controls (Turchaninova et al., Bull Exp Biol Med 2000).

• Transcription. A microarray of 15,247 mouse transcripts found Cortagen altering 234 clones mapping to 110 known genes, the largest change a 5.42-fold increase — measured in heart tissue, not brain (Anisimov et al., 2004).

It also activated interleukin-2 mRNA in rat splenocytes, more weakly than Vilon or Epithalon (Kazakova et al., 2002). Effects in heart and spleen sit awkwardly beside a cortex-specific claim.

Cortagen carries no marketing authorisation in the US, EU, UK, Canada, or Australia and appears in no neurology guideline. The nearest clinical rationale is a Russian-language study in rats of differing hypoxia resistance, reporting that Cortagen and Cortexin sped behavioural recovery and blunted lipid peroxidation in chronic cerebral ischaemia (Zarubina and Shabanov, Eksp Klin Farmakol 2011) — with no doses or effect sizes stated.

Catch-all language for substances with no current regulatory approval can still apply, so a name's absence settles nothing. Tested athletes should route the question through their federation.

Across the indexed Cortagen literature, adverse events are not an endpoint. The rodent studies report growth rates, conduction velocities, and transcript counts; none describes systematic toxicology or adverse-event collection, and no human safety series exists.

So statements that Cortagen is "well tolerated" are unsupported — tolerability was never measured. And a peptide reported to shift 110 genes in a tissue it was not aimed at has off-target behaviour that is unmapped rather than absent.

The only published dosing figure anywhere is the animal one: 10 µg/kg intramuscularly, once daily, for ten days in rats. No human pharmacokinetics for AEDP has been published, and every published experiment used parenteral or direct in-vitro exposure rather than an oral route.

Cortagen and Cortexin are routinely conflated but are not the same product. Cortexin is a polypeptide preparation extracted from animal brain cortex; Cortagen is the defined four-residue synthetic peptide. Russian pharmacology papers study them as a matched pair precisely because they are different classes of material (Zarubina and Shabanov, 2011).

Within the family, AEDP differs from Epithalon (Ala-Glu-Asp-Gly) by one terminal residue — proline instead of glycine — which is the entire structural basis for assigning them to different organs. See Epitalon and Pinealon.

Fifteen or so PubMed records spanning 2000 to 2023, almost all from the originating group, concentrated in Bulletin of Experimental Biology and Medicine — the English translation of Byulleten' Eksperimental'noi Biologii i Meditsiny — plus Doklady Biological Sciences and Georgian Medical News. Sample sizes are rarely given, blinding is not described, and no unaffiliated laboratory has replicated the findings.

Other Cortagen pages here:

• Cortagen benefits and areas of interest
• Cortagen side effects and safety context
• Cortagen dosing concepts (educational)
• Cortagen research and evidence overview

What is Cortagen's sequence? Ala-Glu-Asp-Pro, a tetrapeptide, stated explicitly in the microarray and interleukin-2 papers rather than only on vendor listings.

Has Cortagen been tested in people? No controlled human trial is indexed. Human-facing claims rest on rat experiments and on Russian clinical reports that PubMed does not carry.

Is Cortagen the same as Cortexin? No. Cortexin is an extract of animal brain cortex containing many polypeptides; Cortagen is one defined synthetic tetrapeptide.

What is the strongest single result for it? The sciatic-nerve study — 27% faster regeneration and 40% higher conduction velocity in rats at 10 µg/kg. A peripheral-nerve finding from 2000, never independently repeated, saying nothing directly about cognition.