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Cortagen: Evidence, Mechanism, Dosing & Legal Status

A clinical monograph on Cortagen (Ala-Glu-Asp-Pro) — the Khavinson-program 'cytogen' tetrapeptide marketed for nerve repair and neuroprotection. One intriguing rat nerve-regeneration signal, no human RCTs, and an unapproved-research-chemical legal status.

At a Glance SPEC · CORTAGEN
Class
Synthetic short-peptide bioregulator ('cytogen' tetrapeptide); Khavinson/Russian peptide family; Cortexin-derived neuro/longevity peptide Ala-Glu-Asp-Pro (AEDP)
Sequence / chemistry
Ala-Glu-Asp-Pro; C17H26N4O9; MW ~430.4 g/mol; PubChem CID 18439621 distinct from AEDG / Epitalon
Highest evidence grade
C Preclinical only — animal/in-vitro; no qualifying human efficacy data
Human RCTs
None identified on PubMed/ClinicalTrials.gov
Primary evidenced uses (animal-only)
Peripheral nerve regeneration (rat sciatic model) and brain neuroprotection in chronic/ischemic models
Core mechanism
Hypothesis-grade Khavinson model: tetrapeptide enters cell/nucleus without a receptor, binds gene-promoter DNA and modulates tissue-specific transcription
Dose & route from literature
Animal: 10 µg/kg intramuscular for 10 days; ~0.03 mg/kg behavioral work. No validated human dose informational only
Key risks
No human safety dataset; theoretical malignancy/proliferation concern (gene-modulating mechanism); contamination/sterility/purity hazards from research-chemical vials
FDA status
Not approved; not on 503A compounding bulk lists; sold only as 'research chemical / not for human use'
WADA status
D Not specifically named, but an unapproved-for-human-use injectable falls under S0 (Non-Approved Substances) — treat as prohibited
Informational and editorial only — not medical advice, not a protocol, not a sourcing guide. Dosing figures are reported strictly as seen in the published literature and reported clinical use. Cortagen is not FDA-approved and should be treated as prohibited in sport. Most efficacy claims rest on single-laboratory animal work that has not been independently replicated. Consult a licensed clinician before any health decision.
The short answer

Cortagen (Ala-Glu-Asp-Pro) has one genuinely intriguing animal signal — faster regenerating-nerve growth and conduction in rat sciatic nerve — plus consistent rodent neuroprotection in cerebral ischemia. But no human randomized controlled trials exist, the favorable literature comes almost entirely from one Russian research network, and the highest honest grade is C (preclinical, single-lab, largely unreplicated). It is not FDA-approved, sold only as a research chemical, and carries anti-doping liability.113

Cortagen is a synthetic tetrapeptide developed in the Russian peptide-bioregulator program led by Vladimir Khavinson, designed as a defined-sequence stand-in for Cortexin, an older cattle-brain-cortex polypeptide extract used in Russian neurology.13 Its popularity in longevity and nerve-recovery circles outruns its proof in humans by a wide margin. This monograph separates the two.

This article is informational and editorial content for research and educational purposes only. It is not medical advice, not a protocol to follow, and not a sourcing guide. Cortagen is not an FDA-approved drug; it is sold as a "research chemical not for human use." Dosing figures are reported strictly as seen in the published literature for completeness — not as recommendations. Consult a licensed clinician before any health decision.

What is Cortagen and how does it work?

Cortagen is the tetrapeptide alanyl-glutamyl-aspartyl-proline (Ala-Glu-Asp-Pro, "AEDP"), molecular formula C17H26N4O9, molecular weight about 430.4 g/mol, catalogued as PubChem CID 18439621.10 It was obtained by directed synthesis based on amino-acid analysis of Cortexin and is one member of the broader "cytogen" short-peptide family, with the cerebral cortex and nervous system as its proposed tissue target.3 Note that AEDP (Cortagen, proline) is chemically distinct from AEDG (Epitalon, glycine) and from the Cortexin/AEDG complexes — vendor pages frequently conflate these.

The proposed mechanism is unconventional and, importantly, hypothesis-grade. Unlike receptor-binding peptides, the Khavinson hypothesis holds that di-, tri-, and tetrapeptides are small enough to cross the plasma and nuclear membranes without receptor-mediated transport, then bind specific DNA sequences in gene-promoter regions through electrostatic and steric complementarity, modulating chromatin condensation and tissue-specific transcription.78 Independent biophysical support for nuclear uptake of this peptide class — not Cortagen specifically — comes from fluorescence-labeled short peptides penetrating HeLa-cell nuclei and binding deoxyoligonucleotides in vitro.9 For Cortagen itself, a cDNA-microarray study of mouse heart found 234 clones (1.53%) with altered expression matching 110 known genes, demonstrating that the peptide measurably shifts tissue gene-expression profiles.3 In aged-lymphocyte chromatin, Cortagen has been reported to decondense "old" heterochromatin and reactivate ribosomal genes.6

The critical caveat: this "peptide-into-the-nucleus-binds-DNA" model is largely advanced by one research network and remains mechanistically unconventional and not broadly independently validated. Effect sizes, dosing nonlinearity, and the in-vivo relevance of in-vitro DNA binding are unresolved. No formal pharmacokinetic dataset for Cortagen was identified; as an unprotected linear tetrapeptide it is expected to undergo rapid proteolytic degradation with a very short plasma half-life and negligible oral bioavailability — consistent with why animal studies used parenteral dosing.

What is the evidence by indication?

Every indication below is best understood as animal-model evidence. There are no human RCTs for any of them.

Cortagen evidence by indication
IndicationBest evidenceGrade
Peripheral nerve regenerationRat sciatic-nerve model: +27% growth rate, +40% conduction velocity at 10 µg/kg IM; persistence to 5 monthsC (preclinical)
Brain neuroprotection in chronic ischemiaRat models: faster behavioral recovery, less lipid peroxidation, preserved antioxidant activityC (preclinical)
Gene-expression / "epigenetic anti-aging"Mouse-heart microarray; chromatin decondensation in aged human lymphocytes (in vitro)C-to-D
Cognitive decline, stroke, neurodegeneration, cardiovascular benefitVendor/Russian clinical tradition only; no controlled human efficacy dataD (claim)

The anchor study is the most cited and the most extrapolated. Male Wistar rats with a transected and sutured sciatic nerve received intramuscular Cortagen 10 micrograms per kilogram for 10 days; the growth rate and conduction velocity of regenerating fibers rose 27% and 40%, respectively.1 A follow-up assessed late regeneration at five months post-injury and reported persistence of the regenerative effect into the remyelination phase rather than a transient bump.2 These are small, single-laboratory, same-group studies, and the widely repeated claim of a "pronounced therapeutic effect" on human peripheral nerve recovery is not backed by a retrievable controlled human trial.

For brain neuroprotection, rats with chronic cerebral ischemia treated with Cortexin and Cortagen showed accelerated recovery of disturbed behavior, prevention of excessive lipid peroxidation, and preserved brain antioxidant activity.4 A related paper reported neuroprotective effects during ischemic preconditioning.5 Real, measurable tissue gene-expression shifts were shown by microarray, but the leap from "alters gene expression in mouse heart" to "anti-aging in humans" remains unproven.3 Readers can confirm the absence of registered human trials directly via ClinicalTrials.gov.

Proven vs hyped

Proven: Cortagen changes gene expression and accelerates nerve repair in rodents. Hyped: every human therapeutic claim — nerve recovery, stroke, cognition, anti-aging. The favorable literature originates from one Russian research network, much of it in lower-impact or hard-to-access journals, with vendor pages amplifying introductory "human effect" assertions that lack a controlled trial.6

What doses appear in the literature?

Reported strictly as information, not a protocol. The animal nerve-regeneration dose was Cortagen 10 micrograms per kilogram intramuscular, once daily for 10 days post-injury in rats; behavioral and locomotor work referenced an "optimal" dose around 0.03 milligrams per kilogram in mice.1 There is no validated human dose. Russian-marketed bioregulator products are sold as oral capsules and as lyophilized powder for injection, but "protocols" circulated by research-chemical vendors — for example, 2 to 10 milligrams reconstituted, subcutaneous, in cycles — are not derived from controlled human trials and are not endorsed here. Lyophilized peptide vials of this class are typically reconstituted with bacteriostatic water and refrigerated, but specifics vary by product and lie outside any validated clinical standard. Because the tetrapeptide is expected to degrade rapidly with low oral bioavailability, the controlled animal data used parenteral administration; oral systemic efficacy is unproven.

How safe is Cortagen?

The human safety dataset is essentially absent. No peer-reviewed human safety or adverse-event study was identified, so "well tolerated" claims rest on animal work and uncontrolled Russian clinical use — and absence of reported harm is not the same as demonstrated safety. Locomotor and anxiety studies of this peptide class reported enhanced motor activity without anxiety or emotional-affective disturbance at the tested dose, and no overt adverse effects on acute or sub-chronic dosing in rodents.4 The dominant theoretical risk is mechanistic: any agent proposed to modulate gene expression and stimulate tissue regeneration carries a theoretical concern in malignancy and in actively dividing tissues, which has not been formally studied for Cortagen. Injectable use of non-pharmaceutical-grade research-chemical peptides also carries contamination, endotoxin, sterility, and mislabeling risks independent of the molecule itself. No interaction studies exist. Pregnancy and lactation (no reproductive-toxicity data), children, and individuals with active or recent cancer should be treated as contraindicated by default.

What is the FDA and WADA status?

Cortagen is not approved as a drug in the United States. It is not listed on the FDA's 503A compounding bulk-substance lists and is not an FDA-recognized compounding substance; it is sold in the US only by research-chemical suppliers labeled "for research use only / not for human consumption," which confers no legal pathway to human therapeutic use.12 No EMA, MHRA, Health Canada, or TGA approval was identified. Within Russia, Cortexin is a registered drug and Cortagen-type bioregulators are marketed largely as supplements or registered preparations — but this does not equate to evidence by Western RCT standards.

For athletes, Cortagen is not specifically named on the 2026 WADA Prohibited List; however, as a substance not approved for human therapeutic use by any government regulatory authority, an injectable form is captured by the S0 "Non-Approved Substances" catch-all and should be treated as prohibited at all times.13 Any WADA-tested athlete should re-verify against the current list before competition.

Bottom line. Cortagen pairs one concrete, intriguing preclinical signal — faster rat sciatic-nerve regeneration, sustained to five months — with a near-total absence of human proof. What is proven is that it changes gene expression and accelerates nerve repair in rodents; what is hyped is every human therapeutic claim. Graded C overall, with no human RCTs, no FDA approval, and anti-doping liability, it is promising biology, not a validated human therapeutic. Regulatory and anti-doping facts here are current as of June 2026 and should be re-verified directly before relying on them.

References

Tagged by study type · 13 of 13 shown
#SourceType
1Turchaninova LN, Kolosova LI, Malinin VV, et al. "Effect of tetrapeptide cortagen on regeneration of sciatic nerve." Bull Exp Biol Med 2000;130(12):1172-4 (PMID 11276314). pubmed.ncbi.nlm.nih.gov/11276314Animal
2Turchaninova/Kolosova et al. "Effect of tetrapeptide cortagen on regeneration of sciatic nerve" — late (5-month) regeneration follow-up. semanticscholar.orgAnimal
3Anisimov SV, Khavinson VK, Anisimov VN. "Elucidation of the effect of brain cortex tetrapeptide Cortagen on gene expression in mouse heart by microarray." Neuro Endocrinol Lett 2004;25(1-2):87-93 (PMID 15159690). pubmed.ncbi.nlm.nih.gov/15159690Animal
4Zarubina IV, Shabanov PD. "Cortexin and cortagen as correcting agents in functional and metabolic disorders in the brain in chronic ischemia." Eksp Klin Farmakol 2011;74(2):8-15 (PMID 21476278). pubmed.ncbi.nlm.nih.gov/21476278Animal
5Zarubina IV, Shabanov PD. "Neuroprotective effects of peptides during ischemic preconditioning." Bull Exp Biol Med 2016;160:448-451 (PMID 26902350). pubmed.ncbi.nlm.nih.gov/26902350Animal
6Lezhava T, Khavinson V, et al. "Epigenetic regulation of 'aged' heterochromatin by peptide bioregulator Cortagen." Int J Pept Res Ther 2014;21(1):157-163. link.springer.comIn vitro
7Khavinson VK, et al. Review of short-peptide regulation of gene expression. 2014 (PMID 25437836). pubmed.ncbi.nlm.nih.gov/25437836Review
8Khavinson VK, et al. "Peptide Regulation of Gene Expression: A Systematic Review." Molecules 2021;26(22):7053. mdpi.com/1420-3049/26/22/7053Review
9Fedoreyeva LI, et al. "Penetration of short fluorescence-labeled peptides into the nucleus in HeLa cells and in vitro specific interaction of the peptides with deoxyribooligonucleotides." Biochemistry (Moscow) 2011;76:1210-1219 (PMID 22117548). pubmed.ncbi.nlm.nih.gov/22117548In vitro
10PubChem — Cortagen, CID 18439621 (chemistry / identity). pubchem.ncbi.nlm.nih.gov/compound/18439621Regulatory
11Wikipedia — Cortagen (chemistry, references index; tertiary source). en.wikipedia.org/wiki/CortagenReview
12U.S. Food and Drug Administration — Bulk drug substances used in compounding under section 503A of the FD&C Act. fda.govRegulatory
13World Anti-Doping Agency — 2026 Prohibited List. wada-ama.org/en/prohibited-listRegulatory

Frequently Asked

Common questions · evidence-graded answers

Is Cortagen proven to work in humans?

No. No registered or peer-reviewed human randomized controlled trials of Cortagen were identified on PubMed or ClinicalTrials.gov. The strongest evidence is a small rat sciatic-nerve study showing faster nerve regeneration, plus animal neuroprotection in cerebral ischemia and documented gene-expression shifts in mouse tissue. PeptideVox grades Cortagen C — preclinical, single-laboratory, and largely unreplicated outside its originating Russian research network. The frequently repeated claim that Cortagen has a 'pronounced therapeutic effect' on human peripheral nerve recovery traces back to introductory assertions in review articles and vendor pages, not to a retrievable controlled human trial, and should be read as Grade D when applied to people.

How does Cortagen work?

The proposed mechanism is hypothesis-grade and unconventional. Under the Khavinson model, very short peptides like Cortagen (Ala-Glu-Asp-Pro) are small enough to cross the cell and nuclear membranes without receptor-mediated transport, then bind specific DNA sequences in gene-promoter regions and modulate chromatin condensation and tissue-specific transcription. Supporting biophysical work shows fluorescence-labeled short peptides of this class entering HeLa-cell nuclei and binding deoxyoligonucleotides in vitro. For Cortagen specifically, a microarray study found altered expression of 110 known genes in mouse heart. The critical caveat: this 'peptide-into-the-nucleus-binds-DNA' model is advanced mainly by one research network and is not broadly independently validated, so treat all mechanism statements as hypothesis-grade rather than established.

What is the difference between Cortagen, Cortexin, and Epitalon?

These are related but distinct. Cortexin is an older cattle-brain-cortex polypeptide extract used in Russian neurology — a complex mixture, not a single defined sequence. Cortagen is a synthetic tetrapeptide, Ala-Glu-Asp-Pro ('AEDP'), obtained by directed synthesis based on amino-acid analysis of Cortexin; it is meant as a defined-sequence stand-in for that extract. Epitalon is a different tetrapeptide, Ala-Glu-Asp-Gly ('AEDG'), associated with telomerase and pineal-related research. Vendor pages frequently conflate AEDP (Cortagen, proline) with AEDG (Epitalon, glycine) and with Cortexin/AEDG complexes. They are chemically different molecules with different proposed tissue targets and should not be treated as interchangeable.

What doses of Cortagen appear in the literature?

This is reported strictly as information, not a protocol or recommendation. There is no validated human dose. The anchor animal study dosed rats with Cortagen 10 micrograms per kilogram intramuscularly once daily for 10 days after sciatic-nerve injury, and behavioral work in mice referenced an 'optimal' dose around 0.03 milligrams per kilogram. Russian-marketed bioregulator products are sold as oral capsules and as lyophilized powder for injection, but 'protocols' circulated by research-chemical vendors — for example, 2 to 10 milligrams reconstituted and injected subcutaneously in cycles — are not derived from controlled human trials and are not endorsed here. Because the tetrapeptide is expected to degrade rapidly with low oral bioavailability, the controlled animal data used parenteral administration.

Is Cortagen safe?

There is essentially no human safety dataset. No peer-reviewed human safety or adverse-event study was identified, so 'well tolerated' claims rest only on animal work and uncontrolled Russian clinical use — and absence of reported harm is not the same as demonstrated safety. Rodent studies report enhanced motor activity without anxiety and no overt adverse effects at the tested doses, but no formal human safety data exist. The dominant theoretical concern is mechanistic: any agent proposed to modulate gene expression and stimulate tissue regeneration carries a theoretical risk in active or recent malignancy and in actively dividing tissues, which has not been formally studied. Injectable use of non-pharmaceutical-grade research-chemical peptides also carries contamination, endotoxin, sterility, and mislabeling risks independent of the molecule itself. Pregnancy, lactation, and children should be treated as contraindicated by default.

Is Cortagen legal, and can athletes use it?

Cortagen is not an FDA-approved drug. It is not listed on the FDA's 503A compounding bulk-substance lists and is sold in the United States only by research-chemical suppliers labeled 'for research use only / not for human consumption,' which confers no legal pathway to human therapeutic use. No EMA, MHRA, Health Canada, or TGA approval was identified; in Russia, related bioregulators are marketed domestically, which does not equate to evidence by Western standards. For athletes, Cortagen is not specifically named on the 2026 WADA Prohibited List, but as a substance not approved for human therapeutic use by any government authority, an injectable form is captured by the S0 'Non-Approved Substances' catch-all and should be treated as prohibited at all times. Always re-verify against the current list before competition.

Medical Disclaimer · Read in full

PeptideVox is an evidence reference, not medical advice. Nothing here authorizes you to acquire, possess, or self-administer any compound.

This content is for informational and educational purposes only · No physician–patient relationship is created · Evidence grades reflect published data as of the stated revision and may change.

Medical Disclaimer · Read in full

PeptideVox is an evidence reference, not medical advice. Nothing here authorizes you to acquire, possess, or self-administer any compound.

01 · Not FDA-approved

The majority of compounds documented here are not approved by the FDA for human use. Approved drugs (e.g. semaglutide, tirzepatide) are noted explicitly and require a licensed prescriber.

02 · Research chemicals

Many peptides — including BPC-157 and GHK-Cu in injectable form — are sold strictly "for research use only — not for human consumption." Purity, identity, and dosing of such products are not regulated or guaranteed.

03 · WADA-prohibited

Several compounds are banned in competitive sport under the WADA Prohibited List. Athletes risk sanction regardless of intent or formulation.

04 · Consult a clinician

Always consult a qualified, licensed healthcare professional before considering any compound. Individual risk depends on your full medical context.

This content is for informational and educational purposes only · No physician–patient relationship is created · Evidence grades reflect published data as of the stated revision and may change.