Cortagen

It's like a translation of an old folk remedy into a single, neat ingredient: someone took a crude cow-brain tonic and isolated four 'letters' they thought were the active part. The lab experiments on rats are real and intriguing, but the leap to 'this fixes human nerves and brains' is a translation no one has actually checked against the original in people, and nearly all the checking has been done by the same group who wrote the translation.

Cortagen is the tetrapeptide Ala-Glu-Asp-Pro, designed as a defined-sequence analogue of the active fraction of cortexin (a bovine cerebral-cortex peptide extract). Its proposed mechanism, per the Khavinson group, is the generic short-peptide bioregulator model: the peptide enters cells and the nucleus and interacts sequence-preferentially with promoter DNA and chromatin, modulating transcription of tissue-relevant genes in neural and cardiac tissue. Downstream, this is reported to stimulate nerve regeneration (faster axonal regrowth and conduction velocity after nerve injury), exert neuroprotective and antioxidant effects in ischaemia/hypoxia models, and shift expression of genes involved in development and stress response (e.g. Bmp2, Wnt4, Hsc70 in cardiac microarray work). This direct DNA-interaction model is mechanistically unusual and not independently established; the regenerative and neuroprotective effects are documented mainly in rodents and in vitro.

Research contexts. Not proven uses, and not recommendations.

Thin and low-quality. There are no completed, registered, independent randomised controlled trials of Cortagen for nerve repair, cognition or any other outcome. Older Russian-institute reports describe benefit in cerebrovascular and post-stroke patients, but these are largely open-label or unblinded case series that predate and fall short of modern trial-methodology standards, and they have not been reproduced by independent Western laboratories. The robust, reproducible data are in rats and cultured cells (sciatic-nerve regeneration, ischaemia/hypoxia neuroprotection, cardiac gene-expression microarrays), overwhelmingly from the Khavinson group. Claims of human cognitive enhancement, nerve 'healing' or anti-ageing benefit should be treated as unproven in people.

• !No RCT-grade human efficacy or safety data; the human reports are unblinded Russian-institute work and the strong data are rodent/in-vitro only.
• !Near-total reliance on a single research group with little independent replication, raising publication-bias and reproducibility concerns.
• !Sold as an unlicensed grey-market 'research chemical', usually labelled 'not for human consumption'; no UK marketing authorisation and not prescribable as a recognised therapy.
• !Grey-market products have no guarantee of identity, purity, sterility or endotoxin content; injectable peptides carry infection and contamination risks.
• !The proposed 'peptide enters the nucleus and directly regulates genes' mechanism is contested and not well established outside the originating group.
• !Some confusion exists in marketing material over the exact sequence (Cortagen is AEDP, but it is sometimes mislabelled as an 'AEDG complex'); buyers cannot verify what they are actually receiving.
• !Long-term effects of chronically manipulating gene expression in the brain are entirely unstudied in humans.

Cortagen is not a licensed medicine in the UK and holds no MHRA marketing authorisation. It is not an approved or recognised treatment for nerve injury, stroke, cognition or anything else, and there are no MHRA-authorised UK clinical trials of it. (Cortexin, the related cattle-brain extract it derives from, is a registered drug in Russia but not in the UK.) In practice Cortagen is sold online as an unlicensed 'research chemical', typically labelled 'not for human consumption' to sidestep medicines regulation. Selling or supplying it for human use would engage the Human Medicines Regulations 2012; a UK clinician cannot lawfully prescribe it as a recognised therapy.

1. 01
   Effect of tetrapeptide cortagen on regeneration of sciatic nerve — Turchaninova LN, Kolosova LI, Malinin VV, Moiseeva AB, Nozdrachev AD, Khavinson VK, Bulletin of Experimental Biology and Medicine (2000)

   Rat sciatic-nerve transection model; reported ~27% faster regenerating-fibre growth and ~40% higher conduction velocity with Cortagen. Animal data, originating group.

2. 02
   Elucidation of the effect of brain cortex tetrapeptide Cortagen on gene expression in mouse heart by microarray — Anisimov SV, Khavinson VKh, Anisimov VN, Neuroendocrinology Letters (2004)

   Oligonucleotide-microarray study; ~110 genes altered (incl. Bmp2, Wnt4, Hsc70). Mechanistic/preclinical support for the gene-regulation hypothesis.

3. 03
   Neuroprotective Effects of Peptides during Ischemic Preconditioning — Zarubina IV, Shabanov PD, Bulletin of Experimental Biology and Medicine (2016)

   Rat ischaemia models; neurospecific peptide preparations reduced neurological deficit and showed antioxidant action. Animal data.

4. 04
   [Cortexin and cortagen as correcting agents in functional and metabolic disorders in the brain in chronic ischemia] — Zarubina IV, Shabanov PD, Eksperimental'naia i Klinicheskaia Farmakologiia (Eksp Klin Farmakol) (2011)

   Russian-language rat chronic-cerebral-ischaemia study explicitly testing Cortagen (and cortexin); reported faster recovery of behaviour and reduced lipid peroxidation. Animal data, originating line of research.

5. 05
   Search: Cortagen / brain cortex tetrapeptide AEDP (PubMed), PubMed

   Live search to gauge the small, single-group-dominated primary literature base and the absence of independent RCTs.