27% faster rat sciatic nerve regrowth. No human trial has tested the synthetic peptide yet.
What is it? A synthetic tetrapeptide Ala-Glu-Asp-Pro (AEDP), ~430 Da. Khavinson's proposed active fragment from Cortexin, the calf-cerebral-cortex extract still sold as a prescription drug in Russia.
What does it do? Khavinson's model proposes AEDP engaging chromatin targets in cortical neurons. Preclinical work reports neuroprotection in ischemic and oxidative-stress models, higher BDNF/NGF-axis markers, and improved learning in aged animals.
Does the evidence hold up? Preclinical only. Turchaninova 2000: 27% faster nerve growth and 40% faster conduction in rat sciatic regeneration. Cortexin's Russian clinical record covers the extract, not the synthetic peptide.
Who uses it? Khavinson-bioregulator users and nootropic self-experimenters extending Cortexin's stroke-recovery framework to the defined tetrapeptide. 10–20 day oral or injectable cycles, 2–3 times a year.
Bottom line? The synthetic answer to Cortexin. No independent human trial of AEDP exists.
Cortagen is a synthetic tetrapeptide within the Khavinson bioregulator program. Its sequence is Ala-Glu-Asp-Pro (AEDP), with an approximate molecular weight of 430 daltons. It shares the "Ala-Glu-Asp" acidic core with Khavinson siblings Epithalon (AEDG, pineal), Bronchogen (AEDL, bronchial), and Cardiogen (AEDR, heart) — with proline as the C-terminal residue proposed to confer cortical-tissue specificity.
Cortagen is positioned as the short-peptide active fragment derived from Cortexin, a polypeptide complex extracted from calf cerebral cortex that is — unlike most Khavinson parent extracts — a registered prescription pharmaceutical in Russia. Cortexin is used in Russian neurology for cerebrovascular disease, traumatic brain injury, stroke recovery, pediatric perinatal encephalopathy, and age-related cognitive decline. The Khavinson program's claim is that AEDP represents the defined short peptide responsible for a substantial portion of Cortexin's bioregulatory effect — recovered from enzymatic hydrolysis of the cortex extract.
This Cortexin–Cortagen relationship distinguishes Cortagen within the Khavinson peptide family: the parent extract has a much larger clinical-use evidence base (Russian-language mainly, observational and non-placebo-controlled in much of the literature, but extensive) than any other Khavinson tissue extract. Cortexin's clinical footprint does not, however, directly validate the defined synthetic AEDP tetrapeptide; the data apply to the complex extract, which contains dozens to hundreds of peptides in addition to any specific fragment.
Commercially, synthetic Cortagen is distributed as an oral capsule in the Khavinson Revilab / NPCRiZ dietary-supplement line and as a lyophilized research peptide (typically 20 mg vials) for subcutaneous or intramuscular research use. Cortexin (the parent extract, not the synthetic AEDP) is sold as a prescription injectable pharmaceutical in Russia and several CIS markets.
In the Western optimization community, Cortagen is used in a nootropic / neuroprotective niche within Khavinson-protocol stacks. It is not recognized by Western neurology, and using Cortagen in place of guideline-directed stroke, TBI, or cognitive-impairment care is inappropriate.
Within the Khavinson framework, Cortagen is proposed to act as a tissue-specific short peptide engaging cortical neurons at intracellular / chromatin targets, modulating expression of genes involved in neuronal survival, synaptic plasticity, and neurotrophic-factor signaling. Mechanism is primarily described by the originating research program; independent structural validation is limited.
Limitation: as with other Khavinson peptides, mechanism is primarily a hypothesis advanced within a single research program. The separation of AEDP-specific effects from the broader Cortexin-extract effects is a long-running open question that has not been addressed by independent Western neuroscience research.
Cortagen's evidence base is meaningfully stronger than most Khavinson peptides by virtue of its relationship to the registered pharmaceutical Cortexin. The synthetic AEDP tetrapeptide itself, however, remains preclinical.
Cortagen's evidence base mixes two categorically different kinds of evidence: the extensive but observational / methodologically variable Cortexin parent-extract literature, and the sparse preclinical evidence for the defined synthetic AEDP tetrapeptide. These should not be conflated. No RCTs of synthetic Cortagen exist. Using Cortagen as a substitute for evidence-based stroke, TBI, epilepsy, dementia, or neurodegenerative disease care is inappropriate. Claims that synthetic Cortagen "treats" neurological disease rest on extrapolation from the parent extract, not direct AEDP evidence.
No published randomized controlled human trials of the synthetic AEDP tetrapeptide exist. Accessible human-use information:
The comparative frame for Cortagen in neurology is informative. Ischemic stroke management centers on reperfusion therapy (IV tPA / tenecteplase, mechanical thrombectomy) within time windows established by ECASS, NINDS, DAWN, DEFUSE-3 and others, then secondary prevention with antiplatelets, anticoagulation for cardioembolic sources, statin therapy, and blood-pressure management. Traumatic brain injury care emphasizes intracranial pressure management, osmotic therapy, surgical decompression where indicated, and rehabilitation. Alzheimer's disease now has anti-amyloid monoclonal antibodies (lecanemab, donanemab) in addition to cholinesterase inhibitors and memantine. Parkinson's disease treatment is levodopa-anchored with adjunct agonists and MAO-B inhibitors.
Within this evidence-rich space, Cortagen has no evidence-based positioning. The most mechanistically adjacent agent on the Kalios database is Cerebrolysin — which has 200+ published clinical trials including the CARS / CASTA stroke program, CAPTAIN I/II TBI program, multiple dementia RCTs, and Cochrane-review engagement. Cerebrolysin is not FDA-approved but has legitimate international clinical use and a substantial independent (if sponsor-biased) evidence base. Cortagen has neither FDA approval nor a comparable clinical-trial footprint.
What Cortagen does have, uniquely among Khavinson peptides, is an association with a registered pharmaceutical (Cortexin) whose clinical use is established in approving countries. That association strengthens the scientific narrative — the AEDP tetrapeptide is not an arbitrary short peptide; it is the proposed active fragment of a compound with decades of clinical use. But the narrative is not the evidence. The evidence for synthetic AEDP remains preclinical. Users should weigh the narrative coherence against the actual RCT gap when making decisions.
Where Cortagen is plausibly positioned — as a course-based nootropic / neural-support peptide in the context of general aging or post-viral cognitive concerns, alongside standard care — it is a reasonable experimental addition. Where it is positioned as treatment for stroke, TBI, dementia, or neurodegenerative disease, it is not.
No clinical-trial-derived human dose for synthetic AEDP exists. Doses below summarize the Khavinson protocol framework and community practice. Cortexin parent-extract dosing is entirely separate and is not interchangeable. Not FDA-approved prescribing.
| Form | Typical Dose | Frequency | Cycle / Notes |
|---|---|---|---|
| Oral capsule (Khavinson BAD — Revilab / NPCRiZ) | 200–400 μg | 1–2× daily (AM preferred) | Microdose oral capsule. 10–20 day course, 2–3 courses per year per protocol. |
| Oral lyophilized research peptide | 5–10 mg | Once daily | Community use of injectable-grade peptide orally/sublingually. Order(s)-of-magnitude higher than the BAD capsule; bioavailability poorly characterized. |
| Subcutaneous / IM injection | 100–200 μg | Once daily | Community injectable protocols, 10–20 day courses. The Turchaninova 2000 rat study used 10 μg/kg IM daily for 10 days. |
| Course length | 10–20 days | — | Standard Khavinson cycle. |
| Cycle frequency | 2–3 courses per year | — | Seasonal or elective timing. |
| Cortexin parent extract (for reference — separate product) | 10–20 mg IM | Once daily | 10-day course. Cortexin, not AEDP. Prescription pharmaceutical in approving jurisdictions. |
Large dosage gap between the Khavinson BAD microdose and the community research-peptide oral dose. No validated human PK for synthetic AEDP. Do not conflate Cortagen (synthetic tetrapeptide) and Cortexin (prescription polypeptide extract) — they are different products at different doses with different regulatory status. Self-administration of research peptides for neurological conditions is not a substitute for evidence-based neurology. Morning dosing is practically preferred to minimize the occasional over-stimulation reports on PM dosing.
Research-peptide Cortagen is supplied lyophilized, typically in 10 mg or 20 mg vials. Oral BAD capsules are pre-formulated. Cortexin parent extract is a separate prescription product with its own preparation.
| Vial | BAC Water | Concentration | 100 μg Dose | 200 μg Dose |
|---|---|---|---|---|
| 10 mg | 2 mL | 5 mg/mL (5,000 μg/mL) | 2 units (0.02 mL) | 4 units (0.04 mL) |
| 10 mg | 5 mL | 2 mg/mL (2,000 μg/mL) | 5 units (0.05 mL) | 10 units (0.10 mL) |
| 20 mg | 2 mL | 10 mg/mL (10,000 μg/mL) | 1 unit (0.01 mL) | 2 units (0.02 mL) |
| 20 mg | 5 mL | 4 mg/mL (4,000 μg/mL) | 2.5 units (0.025 mL) | 5 units (0.05 mL) |
Pinealon (EDR tripeptide) targets pineal-/hippocampal-axis endpoints; Cortagen (AEDP tetrapeptide) targets cortex. Common co-cycled pairing within Khavinson neuro-protocols. Preclinical-only combination.
Semax (Russian-developed ACTH(4-10) analog) provides acute BDNF elevation and nootropic effects. Frequently paired with Cortagen as a longer-term neuroprotective adjunct in nootropic community protocols.
Cerebrolysin (porcine brain peptide hydrolysate) has the largest clinical-trial database of any neurorecovery peptide. Mechanistically overlapping with Cortagen / Cortexin in general framework (neurotrophic mimicry) but Cerebrolysin is a very different product with 200+ published clinical trials. Used in aggressive post-stroke and post-TBI rehabilitation in approving countries.
Most-studied Khavinson peptide; commonly included in broader longevity stacks alongside tissue-specific peptides such as Cortagen.
Dihexa is a non-Khavinson nootropic acting via hepatocyte growth factor (HGF) signaling. Mechanistically distinct; community protocols sometimes pair these for cognitive goals.
Synthetic Cortagen is not approved by the U.S. FDA for any indication and has not been the subject of an IND or NDA filing. It is not approved by the European Medicines Agency.
Cortexin (the polypeptide parent extract, not synthetic AEDP) is a registered prescription pharmaceutical in Russia and several CIS jurisdictions, approved for cerebrovascular disease, TBI sequelae, pediatric cerebral palsy and developmental delay, and age-related cognitive disorders. Cortexin is not FDA- or EMA-approved in the U.S. or EU central market. Do not confuse regulatory status of Cortexin and Cortagen — they are different products.
Synthetic Cortagen is sold in Russia as a "biologically active additive" (BAD — dietary supplement) through Khavinson-affiliated distributors (NPCRiZ, Revilab). It is not a registered pharmaceutical.
Cortagen is not on the FDA Category 2 Bulk Drug Substances list, and it is not among the peptides under HHS Secretary Robert F. Kennedy Jr.'s February 2026 Category 2 reclassification announcement.
Cortagen is not specifically named on the WADA Prohibited List. Athletes should consult their sport-specific federation.
Synthetic Cortagen is not approved for human use in the United States. The oral BAD form is distributed internationally through Khavinson-affiliated channels; the injectable lyophilized peptide is available through research-chemical suppliers for laboratory research use only. Personal-use import to the U.S. occupies a legal gray zone.
No U.S. compounding pharmacy can legally compound Cortagen — it has no FDA-approved reference product and is not on the Category 1 bulk substance list. Purity verification via third-party HPLC + MS COA is the practical quality floor.
Cortexin (parent extract) is dispensed on prescription in approving jurisdictions and administered intramuscularly in clinical settings. It is not available through U.S. channels.
Cortagen is not among the peptides under HHS Secretary Robert F. Kennedy Jr.'s February 2026 Category 2 reclassification announcement. Absent formal FDA development of either Cortagen or Cortexin, neither will be available through legitimate U.S. clinical channels.
Access and availability information as of April 2026. Kalios does not sell compounds.
People researching Cortagen often also look at these:
Khavinson tripeptide (Ala-Glu-Asp). Cartilage and joint-oriented short peptide bioregulator.
Khavinson tetrapeptide (Lys-Glu-Asp-Ala). Liver-oriented short peptide bioregulator.
Khavinson tetrapeptide (Lys-Glu-Asp-Trp). Pancreas-oriented bioregulator.
Khavinson tripeptide (Glu-Asp-Leu). Hepatic/immune short-peptide bioregulator.
Cerebrolysin-derived synthetic peptide engineered to retain the neurotrophic core activity.
Last updated: April 2026 | Profile authored by Kalios Peptides research team