Brain-protective peptide (Cortagen / AEDP)
A lab-made four-amino-acid peptide studied in animals for protecting brain and nerve tissue; sold in Russia as a supplement, not an approved drug anywhere.
- Class
- Synthetic tetrapeptide bioregulator (Khavinson program)
- Status
- Not approved by FDA, EMA, Health Canada, MHRA, or any equivalent major reference regulator. Marketed in Russia and CIS as a dietary peptide complex; not a registered pharmaceutical.
- Best-supported effect
- Sciatic nerve regeneration markers and brain function parameters in rodent models (preclinical animal studies, Khavinson group only).
- Main caveat
- Cortagen-specific preclinical evidence is sparse and concentrated in a single Russian research network with no independent Western replication; human efficacy is not established; cognitive-enhancement claims in healthy adults are not supported by peptide-specific evidence.
A researcher, an agent, or an algorithm wrote down the sequence and picked a target to hit.
An AI model like OpenFold3 or AlphaFold built a 3D structure and scored how well it fits the binding site.
A second contributor repeated the computation on their own hardware and the scores matched.
A chemistry service or a researcher ordered the sequence, it was manufactured, and mass spectrometry confirmed the right molecule was produced.
A binding or activity measurement confirmed that it actually does what the computer predicted — or didn't.
Snapshot
Class: Synthetic tetrapeptide bioregulator (Khavinson program)
Evidence tier: Animal-only evidence
Status: Not approved by FDA, EMA, Health Canada, MHRA, or any equivalent major reference regulator; marketed in Russia and CIS as a dietary peptide complex, not as a registered pharmaceutical
Best-supported effect: Sciatic nerve regeneration markers and brain function parameters in rodent models — animal studies from the Khavinson research group only (preclinical)
Main caveat: Cortagen-specific evidence is sparse, concentrated in a single Russian research network, and absent of independent Western replication; human efficacy is not established; cognitive-enhancement claims in healthy adults significantly exceed what the peptide-specific evidence supports
What this is
Cortagen is a synthetic tetrapeptide with the sequence Ala-Glu-Asp-Pro (AEDP), developed within Vladimir Khavinson's bioregulator program at the St. Petersburg Institute of Bioregulation and Gerontology. It was designed as the chemically defined short-peptide counterpart of Cortexin, an older natural-extract preparation derived from cattle cerebral cortex tissue that the Khavinson group and Russian clinicians used in neurology from the 1980s onward. The design logic — common across the Khavinson bioregulator series — is to identify a putative short-peptide active motif from a larger tissue extract, synthesize it as a single defined molecule, and attribute tissue-specific gene-regulatory effects to that molecule.
Cortagen and Cortexin are related but distinct preparations. Evidence for one does not transfer cleanly to the other, and this distinction is frequently overlooked in community and nootropic contexts. The published preclinical record specific to Cortagen consists of a small number of animal and in vitro studies from the Khavinson group and Russian collaborators; independent Western replication is essentially absent.
Evidence map
| Evidence layer | Grade | What it supports |
|---|---|---|
| Human | None identified | No controlled human trial data for Cortagen are present in available literature. "small studies in elderly patients with cognitive decline, primarily from Russian institutions," but no individually extractable controlled efficacy results are attached; this description does not meet the threshold for human-tier evidence. |
| Animal | Weak | Sciatic nerve regeneration markers in rat models; microarray-detected gene expression changes in mouse heart; brain function parameters in a chronic cerebral ischemia model. All studies trace to the Khavinson group and Russian collaborators. No independent Western replication is identified in available literature. |
| In vitro | Weak | Short-peptide effect on interleukin-2 gene expression in splenocytes (one study; Khavinson group; indirect relevance to cortical neuroprotection claims). |
| Computational | None identified | No docking, structure prediction, or model scores are identifieds source. |
| Mechanism | Plausible — contested | Proposed direct DNA interaction by the tetrapeptide to modulate cortical neuron gene expression. Short-peptide gene-regulatory activity is plausible as a class effect, but the specific direct-DNA-interaction mechanism proposed for Cortagen has not been validated by independent biochemical confirmation. |
Replication caveat: Substantially all Cortagen-specific preclinical evidence originates from the Khavinson research program and Russian collaborators. Independent Western replication is essentially absent from the published record present in available literature. Confidence in the preclinical findings is limited by this concentration of evidence in a single research network.
Claim check
| Claim | Verdict | Evidence layer | Confidence |
|---|---|---|---|
| Supports nerve regeneration in animal models | Supported (preclinical) | Animal | Medium — Khavinson-group studies only; no independent Western replication |
| Brain function improvement in chronic ischemia models | Supported (preclinical) | Animal | Low — single study, single research group, no replication; also reports combined cortagen/cortexin, not cortagen alone |
| Cognitive enhancement or memory improvement in healthy adults | Not established | None for this claim | High — published literature explicitly states claims significantly exceed peptide-specific evidence; no human trial data for healthy adults in source |
| Cognitive benefit in humans with cognitive decline | Not established | Human (human-adjacent only) | High — source describes uncontrolled Russian small studies; no individually extractable controlled efficacy result; insufficient for established human efficacy |
| Cortagen and Cortexin are interchangeable | Contradicted | Source narrative | High — source directly addresses this as a common misconception; they are related but distinct preparations with different evidence bases |
| Direct DNA-interaction mechanism is independently validated | Weak / not independently validated | In vitro | Medium — proposed by the Khavinson group; not confirmed by independent biochemical study |
Experimental exposure
This section reports exposure used in animal experiments cited in available literature. It does not establish human dosing.
| Context | System | Experimental exposure | Duration | Endpoint | Limitation |
|---|---|---|---|---|---|
| Animal experiment | Rat sciatic nerve injury model | Cortagen; exact dose not individually extracted in source | Not individually extracted in source | Nerve regeneration and function restoration markers | Single research group; exact dose not extracted; no independent replication; no human translation established |
| Animal experiment | Mouse heart tissue (microarray) | Brain cortex tetrapeptide Cortagen; exact dose not individually extracted | Not individually extracted in source | Microarray gene expression profile | Endpoint is gene expression in heart tissue — indirect relevance to brain cortex neuroprotection claims; Khavinson group only |
| Animal experiment | Chronic cerebral ischemia model (species not individually extracted in source) | Cortagen and/or Cortexin combined per study; exact dose not individually extracted | Not individually extracted in source | Brain function and metabolic disorder markers | Study includes Cortexin alongside Cortagen; individual drug attribution not separately extracted; no human translation established |
Preclinical safety signals
| Signal | System | Notes |
|---|---|---|
| No major toxicity reported in available preclinical studies | Rat/mouse (Khavinson-group studies) | Limited number and scope; no systematic toxicology program described in source |
| Pregnancy and reproductive toxicology | Not studied | Source notes no adequate reproductive toxicology data; classified as not recommended in pregnancy |
| Seizure-threshold effects | Not studied | Neuromodulatory short peptides not adequately studied for seizure-threshold effects per source |
| CNS malignancy context | Theoretical concern noted in source | Source notes theoretical concern in active or recent-history CNS malignancy given proposed neuronal gene-expression modulation; not independently studied |
| Long-term cumulative effects | Not established | Repeated-course cumulative safety has not been independently studied; neurogenesis-related risk not characterized |
| Human safety data | None identified | No formal human safety trial data individually extracted in available literature |
Regulatory status
| Region / body | Status | Notes |
|---|---|---|
| US (FDA) | Not approved | Not approved for any indication; not recognized as a dietary supplement ingredient; not on the FDA 503A compounding list; injectable forms available only through research-chemical suppliers not authorized for human use |
| EU (EMA) | Not approved | per available sources; EMA approval not identified in source |
| UK (MHRA) | Not approved | per available sources; not identified as approved |
| Canada (Health Canada) | Not approved | per available sources; not identified as approved |
| Russia / CIS | Marketed as dietary peptide complex | Khavinson-affiliated oral and sublingual products sold as dietary peptide complexes (e.g., Peptides.ru), not as registered pharmaceuticals; dietary-complex registration is a lower-evidence regulatory category not equivalent to Western prescription-drug approval |
| WADA | Likely prohibited for injectable forms — per available sources; current list not independently refreshed in this card | Source states Cortagen is not specifically named on the WADA Prohibited List; Per available sources, that as an unapproved substance the S0 catch-all category likely applies to injectable forms for athletes subject to WADA code |
Mechanism
Cortagen is proposed by the Khavinson program to act through direct interaction with DNA in cortical neurons, modulating the expression of genes involved in neuronal survival, synaptic plasticity, and neurotransmitter synthesis. The proposed mechanism includes chromatin remodeling and epigenetic effects that may counteract age-related changes in cortical gene expression. The gene-regulatory effects described in the microarray reference were measured in mouse heart tissue, not brain cortex, which complicates the cortex-specificity rationale.
Short-peptide gene-regulatory activity is plausible as a biological class effect. However, the specific direct-DNA-interaction mechanism attributed to the AEDP tetrapeptide has not been independently validated by biochemical confirmation outside the Khavinson program. Target confidence is rated inferred, not verified. No binding affinity data or defined molecular target for AEDP are present in available literature.
Chemistry
| Field | Value |
|---|---|
| Amino-acid sequence | Ala-Glu-Asp-Pro (AEDP) |
| Length | 4 amino acids |
| Topology | Linear |
| Modifications | None described in source |
| Molecular weight | Not individually extracted in source |
| Formula | Not individually extracted in source |
| CAS | Not present in source |
| Sequence confidence | Needs review — source body consistently identifies Ala-Glu-Asp-Pro (AEDP), but published research overview header uses "AEDG Peptide Complex" (G = glycine rather than P = proline). The AEDP form is the consistently described four-residue sequence throughout published research narrative; the AEDG header label may reflect a source-level artifact. No primary analytical chemistry reference is attached to resolve this discrepancy. |
Open questions
- Human controlled trials: No controlled human efficacy data for Cortagen are present in available literature. Whether animal-model effects — nerve regeneration markers, chronic ischemia brain function parameters — translate to any measurable clinical benefit in humans has not been established.
- Independent preclinical replication: Substantially all Cortagen preclinical data originate from the Khavinson research group and Russian collaborators. Independent Western laboratories have not replicated the core findings under modern trial-methodology standards. Replication is the primary bottleneck in the evidence base.
- Mechanism validation: The proposed direct-DNA-interaction mechanism for the AEDP tetrapeptide has not been independently confirmed. Whether any observed effects are mediated by this specific mechanism, by downstream peptide metabolites, or by another pathway is unresolved.
- Pharmacokinetics: Absorption of the intact short tetrapeptide — particularly oral and sublingual bioavailability — has not been independently characterized for Cortagen. Blood-brain-barrier penetration is assumed by the originating program but has not been confirmed by independent pharmacokinetic study.
- Cortagen versus Cortexin distinction: Much of the cognitive and neuroprotective context in nootropic communities draws on the broader Cortexin literature. Cleanly attributing effects to the AEDP tetrapeptide specifically, rather than to the natural cortex-extract tradition, has not been adequately established.
- Long-term safety: Cumulative effects of repeated courses have not been independently studied. Potential effects on neurogenesis-related risk, seizure threshold, and interactions with psychotropic, anticonvulsant, or oncology medications are uncharacterized. The absence of documented major adverse events in limited short-course preclinical studies does not establish safety over repeated use.
- AEDG vs AEDP sequence: Published research header refers to "AEDG Peptide Complex" while published research body consistently uses "AEDP." Whether AEDG is a separate peptide, a labeling error, or an alternate form requires verification against a primary chemistry source.
Research directions for this peptide, selected from the current sources — hypotheses you can explore and model. None of it is proven yet; tap any one to see the full thinking.
Does AEDP last longer in brain tissue than similar peptides because its last building block blocks the enzyme that normally destroys it there?
If this is true, it would explain the brain-targeting of the whole Khavinson neuroprotective series and give researchers a simple rule for designing longer-lasting brain peptides, accelerating development of treatments for neurodegenerative diseases where getting drugs to persist in the brain is a critical challenge.
If proline is replaced by any other amino acid in AEDP, does it lose its ability to protect brain cells even though the rest of the sequence is unchanged?
If proline is proven essential for AEDP's brain activity, chemists could build a locked version of this shape that is stable and potent, which would accelerate the development of a structurally defined neuroprotective drug for conditions like stroke recovery or early Alzheimer's disease.
▸full evidence table2 metrics
| metric | value | tool |
|---|---|---|
| ipTM | 0.872575044631958 | openfold3-mlx |
| ranking score | 0.9164835810661316 | openfold3-mlx |
▸structural qualityopenfold3
| metric | value | note |
|---|---|---|
| gpde | 0.410 | global PDE — lower = better |
| disorder | 0.088 | fraction disordered |
| chain pair ipTM (A, B) | 0.873 | interface quality |
▸3-letter notation
▸recipeopenfold3-mlx 0.3.1
| parameter | value |
|---|---|
| model | openfold3-mlx 0.3.1 |
| weights | — |
| hardware | — |
| mlx version | — |
| python | — |
| random seed | — |
| msa strategy | — |
| diffusion samples | 1 |
| runtime | 78s |
| predicted by | mlx@peptide |
| predicted at | 2026-05-03 |
▸citationbibtex
@peptide{pep10933,
sequence = {AEDP},
target = {neuroprotective},
author = {peptidemodel},
year = {2026},
status = {computed}
}