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Cortagen5 residuesAEDPGEach bubble = one amino acid. Size = residue mass. Color = chemical class.Also known as: AEDP tetrapeptide, Brain bioregulator peptide
Four amino acids long and it changed nerve growth rates by 27% in a single animal study. Cortagen (Ala-Glu-Asp-Pro) is a synthetic tetrapeptide from Vladimir Khavinson's bioregulator program, designed to target cerebral cortex tissue at the epigenetic level. The catch: every published study comes from one Russian lab, and no controlled human trial has ever been run. It's mainly used by biohackers running Khavinson longevity stacks who are betting on the gene expression theory before official Western science catches up.
Cortagen (Ala-Glu-Asp-Pro, MW ~416 Da) is a synthetic four-amino-acid bioregulator targeting neural tissue gene expression. The most-cited result: sciatic nerve fibers grew 27% faster and conducted signals 40% better than controls after 10 days of injections in rats (Khavinson et al.)[1]. Cortagen is a bioregulator developed by Professor Vladimir Khavinson's group at the St. Petersburg Institute of Bioregulation and Gerontology. It was isolated through amino acid analysis of Cortexin, a polypeptide extract from bovine cerebral cortex. The mechanism is unusual. Because it's so small, Cortagen can cross both cell and nuclear membranes. Inside the nucleus, it binds promoter regions of genes tied to neurotrophic signaling and stress response. Microarray data from mouse studies [2] showed modulation of 110 known genes after just 5 days. At the epigenetic level, the peptide triggers deheterochromatinization, reactivating silenced chromatin in aged cells without disturbing structural pericentromeric regions. The oral capsule protocol (10 to 20 mg per day for 10 to 30 days) is the standard Khavinson human-use format. Community interest sits in the niche tier, with fewer than 50 identifiable user reports across Reddit and biohacking forums. Formal clinical evidence in humans? None in indexed English literature. The entire research base comes from one lab, using animal models, with no independent Western replication.
Most peptides work through receptor binding on cell surfaces. Cortagen skips that step entirely. At roughly 416 daltons, the tetrapeptide is small enough to pass through both cell membranes and the nuclear envelope without a transport protein. Once inside the nucleus, it binds specific DNA sequences in promoter regions. The downstream targets include neurotrophic factors (BDNF, NGF) and antioxidant enzymes (SOD, catalase). Oxidative stress markers drop in treated tissue. The more interesting piece is the epigenetic activity. In aged lymphocytes, Cortagen triggers selective deheterochromatinization. That means it loosens tightly packed, silenced chromatin (facultative heterochromatin) without touching the structural pericentromeric regions. Genes that were turned off during aging get switched back on; constitutive heterochromatin stays intact. The remodeling is targeted, not chaotic. Microarray analysis in mice confirmed this isn't subtle [2]. A 5-day course of Cortagen changed expression of 110 known genes across categories including signal transduction, transcription factors, and cellular stress response. One methodological flag: that study used heart tissue, even though Cortagen's claimed specificity is for cerebral cortex. The tissue-specificity claim rests on separate explant data showing selective growth stimulation of rat brain cortex cultures but not other organ tissues [3].
Preclinical evidence only. IM injection in rats accelerated sciatic nerve regeneration (+27% fiber growth rate, +40% conduction velocity over 10 days). Microarray showed modulation of 110 known genes in mouse heart after 5-day course. Epigenetic deheterochromatinization documented in aged lymphocytes in vitro (2014). Neuroprotection in cerebral ischemia models demonstrated. No published human RCTs. No independent Western replication of any study.
Khavinson et al. (2001): "Effect of Tetrapeptide Cortagen on Regeneration of Sciatic Nerve." Neuroscience & Behavioral Physiology. PMID 11276314. IM 10 µg/kg/day × 10 days post-transection in rats; +27% nerve growth rate, +40% conduction velocity.
All research from one lab (Khavinson group, St. Petersburg). No independent Western replication of any study. No human RCTs or dose-finding trials. Animal studies use IM injection: community uses oral or SC at entirely different dose scales with no PK bridging data. Oral bioavailability for unmodified tetrapeptides estimated at <10%, and blood-brain barrier penetration for oral doses is unconfirmed. The 110-gene microarray study (PMID 15159690) used heart tissue despite Cortagen's claimed cortex-specificity: a methodological inconsistency. The tissue-specificity mechanism (explant growth selectivity) has not been independently replicated.
Very niche peptide. Occasional mentions in r/nootropics, r/Peptides, and r/longevity, primarily among Khavinson bioregulator enthusiasts. Most community interest centers on cognitive support, epigenetic longevity protocols, and peripheral nerve injury recovery. Sentiment is cautiously curious rather than strongly positive. Very few users report subjective effects they can clearly attribute to Cortagen alone: usually taken as part of a multi-bioregulator stack.
Goals align (neuroprotection, nerve support, epigenetic longevity) but the delivery is mismatched. Published science uses IM injection in animals; community uses oral capsules at mg-scale doses with estimated <10% bioavailability and no confirmed CNS penetration. Community enthusiasm is driven by the Khavinson brand and the compelling nerve regeneration headline (+27% growth, +40% conduction velocity), but these effects were in an injectable animal model. Whether oral dosing produces any biologically meaningful effect in humans is genuinely unknown.
| Level | Dose / Injection | Frequency |
|---|---|---|
| Beginner | 10mg | Daily |
| Moderate | 20mg | Daily |
| Aggressive | 20mg | Daily |
Cortagen is an oral capsule peptide. No reconstitution, no bacteriostatic water, no syringes for the standard protocol. Swallow with water on an empty stomach, 15 to 30 minutes before your first meal. Morning dosing is the move; a handful of users noticed mild stimulatory effects that interfered with sleep if taken later. Standard Khavinson course: 10 mg per day for 20 to 30 days, then stop for at least 3 months. Repeat 2 to 3 times per year. The 20 mg dose is the upper published range, appropriate for a second cycle after tolerating 10 mg. If you're using the injectable SC route (a separate sterile vial, not capsule contents): reconstitute a 10 mg vial with 2 mL bacteriostatic water to get 5 mg/mL (5,000 mcg/mL). On a U-100 insulin syringe, 0.2 mg equals 4 units. A 0.3 mg dose is 6 units. A 0.5 mg dose is 10 units (0.1 mL). Use within 28 days refrigerated. 29 to 31 gauge needle, abdomen or deltoid. The thing most people miss: Cortagen and Cortexin are different products. Don't confuse them and don't stack them together.
Standard Khavinson bioregulator protocol: 10-30 day courses taken 2-3 times per year with at least 3-month intervals between courses.
The Khavinson 10–30 day on / 3-month off cycle was designed empirically, not from dose-response or tolerance data. The rationale is that short peptide bioregulators are theorized to produce persistent epigenetic effects that outlast the active dosing period: making continuous use unnecessary and potentially counterproductive. The 3-month off interval also provides a monitoring window to detect any unintended consequences from broad gene expression modulation (110+ genes). No receptor desensitization mechanism has been identified for Cortagen specifically.
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Expected: No reliably documented acute human effects. Some users report mild cognitive clarity during the course. Gene expression changes in animal models begin within the first 5 days. Epigenetic remodeling of aged chromatin is theorized to require multiple cycles over time.
Monitor: No validated biomarkers for Cortagen response are available to consumers. If targeting cognitive function, use a validated cognitive test (Cambridge Brain Sciences, CNS Vital Signs) before and after the course to assess change. The effect, if present, is likely subtle.
Cortagen oral capsules (10 mg or 20 mg) for the standard protocol. Injectable vials are a separate product for the SC route only.
For oral dosing: take one capsule (10 mg beginner, 20 mg moderate) on an empty stomach with water. Time it 15 to 30 minutes before your first meal of the day.
Avoid afternoon or evening dosing to prevent mild stimulatory effects near bedtime.
Most community users choose 20 to 30 days at the beginner dose.
After completing the active course, stop completely for a minimum of 12 weeks (3 months) before starting the next cycle. The Khavinson protocol calls for 2 to 3 courses per year.
For injectable SC (advanced, researchers only): reconstitute a 10 mg vial with 2 mL bacteriostatic water to get 5 mg/mL. Draw your dose with a 29 to 31 gauge insulin syringe. At this concentration, 0.2 mg equals 4 units, 0.3 mg equals 6 units, and 0.5 mg equals 10 units. Inject subcutaneously in the abdomen or deltoid area. Rotate injection sites. Refrigerate the reconstituted vial and discard after 28 days.
Track cognitive function before and after the course using a validated tool (Cambridge Brain Sciences or CNS Vital Signs). Subjective impressions alone are unreliable for a peptide with this level of subtlety.
10–20 mg/day (oral, mg scale)
The Khavinson group's human-use data uses oral capsules. The paradox is that published animal efficacy data uses injectable IM. Whether oral dosing achieves meaningful brain tissue concentrations is scientifically unconfirmed.
0.1–1 mg/day (injectable, µg-to-mg scale) vs. 10–20 mg oral
Higher systemic bioavailability vs. oral expected but unquantified. Community consensus clusters around 0.2–0.5 mg SC/day. Requires sterile injectable-grade Cortagen (separate from oral capsules) and injection technique.
10 µg/kg IM in rats: approximately 0.7 mg for a 70 kg human by direct scaling (does not account for species differences)
IM dosing in humans is not standard for research peptide use and not recommended outside clinical settings. The animal-to-human dose extrapolation is not validated.
Canonical Khavinson systemic longevity pairing. Epithalon targets pineal function and telomerase; Cortagen targets cortical epigenetic remodeling. Commonly co-cycled as a "brain + longevity" Khavinson protocol.
Run concurrently during oral active course, or cycle back-to-back. Both 10–20 day courses, 2–3x/year.
Complementary Khavinson neural bioregulator. Pinealon (Glu-Asp-Arg) targets pineal and neural tissue; Cortagen targets cortical tissue. Community "brain bioregulator stack" pairing: theoretically complementary tissue targets.
Oral concurrent with Cortagen course, or sequential. Ventfort + Pinealon + Cortagen is a named community stack for vascular + neuronal support.
Khavinson systemic multi-organ protocol. Thymalin addresses immune senescence; Cortagen addresses neural epigenetics. Khavinson clinical programs used multi-bioregulator protocols combining immune and neural peptides.
Concurrent Khavinson multi-bioregulator course. Each run at standard oral dose for 10–30 days.
Cognitive enhancement pairing with complementary mechanisms. Semax upregulates BDNF and BDNF/NGF signaling acutely; Cortagen is theorized to remodel epigenetic architecture over weeks. Different timescales, potentially additive neuroprotective effects.
Semax intranasal 300–600 mcg/day concurrent with Cortagen oral course.
Cortagen is the synthetic tetrapeptide derived from Cortexin. Combining them adds no known benefit and may cause redundant or unpredictable gene expression overlap. Cortexin already contains the peptide fractions Cortagen is based on.
Cortagen modulates 110+ genes including those related to neural signaling. No formal interaction studies exist, but concurrent use with anticonvulsants in a CNS-active treatment setting carries theoretical risk of unpredictable additive or antagonistic CNS effects.
Broad gene expression modulation affecting neural signaling pathways raises theoretical concern for unpredictable interactions with CNS-active drugs. No formal studies published. Use under medical supervision if combining.
Pricing updated 2026-04-09
Cortagen has never been evaluated in a controlled human safety trial. The side effect profile is genuinely unknown, not "well-characterized" or "mild." That distinction matters. The theoretical concerns carry real weight because of what this peptide actually does. Cortagen modulates expression of 110 or more genes. Gene expression changes at that scale in a person with an undiagnosed malignancy could, in theory, accelerate tumor growth. Active cancer is a hard contraindication. This isn't a generic legal disclaimer; it reflects a genuine mechanistic risk from broad transcriptional modulation. In the nerve regeneration rat study [1], no adverse effects were reported during the 10-day intramuscular course. Rat toxicology data has limited predictive value for human oral dosing at substantially different dose scales. For oral capsule users, the expected side effects are mild. Gastrointestinal discomfort is possible from capsule delivery. Some users avoid evening dosing because of reported mild stimulatory effects, though with fewer than 50 total identifiable user reports, that signal is too small to quantify. The injectable subcutaneous route (0.2 to 0.5 mg per day) adds injection-site risks that oral users don't face. Redness, swelling, and nodule formation at the injection site are standard concerns for any subcutaneous peptide. Sterility is the bigger concern; research-grade injectable vials lack pharmaceutical-standard oversight. A contaminated vial means infection risk that has nothing to do with Cortagen's pharmacology. Oral capsule content should never be injected. No formal drug interaction studies have been published. Theoretical caution applies to CNS-active medications. Antidepressants, antipsychotics, and anticonvulsants like valproate and carbamazepine operate on neural signaling pathways that Cortagen's gene modulation touches. Interactions are unpredictable, not necessarily dangerous, but entirely unstudied. Contraindications: pregnancy and breastfeeding (zero safety data), active malignancy (gene expression risk), known hypersensitivity to any formulation component, and pediatric use under 18 (no data). When to stop: discontinue immediately if any new mass or growth develops. Stop if you experience unexpected neurological symptoms during or after a course, including visual changes, coordination problems, or unfamiliar headache patterns. The gene expression scope of this peptide means unusual symptoms deserve prompt medical attention.
Verify Cortagen dosing and safety with a second opinion
Simple tetrapeptide (Ala-Glu-Asp-Pro, MW ~416 Da) is straightforward to synthesize but also easy to mislabel or substitute. All supply is research-grade with no pharmaceutical-standard regulatory oversight. Injectable form adds sterility risk absent from oral capsule.
| Test | When | Target |
|---|---|---|
| Cognitive function assessment | Baseline before first course, end of first course, 4 weeks post-course | Validated tool (Cambridge Brain Sciences or CNS Vital Signs): track relative change from baseline, not absolute scores |
| Neurological symptom log | Daily during active course | No new neurological symptoms (headache beyond normal, visual changes, coordination changes) |
| Basic metabolic panel / CBC | Baseline before first course if stacking with other neuroactive peptides | — |
Only practical way to track response given no blood biomarkers exist for Cortagen
Identify any unexpected CNS effects from broad gene expression modulation
No Cortagen-specific abnormalities expected, but prudent baseline for any research protocol involving CNS-active compounds
No well-documented acute effects in humans. Gene expression changes begin within the first few days based on animal models.
Continued gene expression modulation expected. Some users anecdotally report subtle improvements in mental clarity.
Full course completion. Animal studies suggest peak effects on nerve regeneration occur toward the end of treatment courses.
Effects from epigenetic remodeling may persist well beyond the active dosing period.
Days 1 to 5, Course Initiation: Gene expression changes kicked off within the first five days in the mouse microarray study [2]. In humans, nobody has measured plasma levels after oral dosing because no pharmacokinetic study has been published. Most users report nothing perceptible in this window. A few mention mild morning alertness, though attributing that to Cortagen specifically is a stretch. Days 6 to 14, Active Course Mid-Phase: Animal models show continued gene modulation during this period. The deheterochromatinization of aged chromatin documented in vitro required multi-day peptide exposure. The rat nerve study accumulated its growth effects over a 10-day course. Community users sometimes report subtle clarity or focus improvements here, but these are inconsistent and hard to separate from other peptides in a stack. Days 15 to 30, Full Course Completion: Animal nerve regeneration data points to peak effects near the end of the treatment window. A minority of users describe a modest sense of cognitive well-being around course completion. The community sample size is too small for any reliable pattern; fewer than 50 user reports total exist online. Weeks 4 to 16, Off-Cycle Persistence Phase: Khavinson's theory holds that epigenetic remodeling from short peptide courses persists after you stop taking them. No human longitudinal data confirms or denies how long any effect lasts. Unlike Epithalon, which has melatonin output as a trackable subjective marker, Cortagen offers nothing users can self-monitor during the off-cycle. The three-month break is empirical tradition, not evidence-based pharmacology.
Gene expression changes begin within the first 5 days in animal models (mouse microarray data, PMID 15159690). No human PK data; plasma levels after oral dosing are uncharacterized.
No perceptible effects reported in this window by most users. Occasionally: mild morning alertness attributed to the course start.
Continued gene modulation expected in animal models. Deheterochromatinization of aged chromatin documented in vitro after multi-day exposure. Nerve fiber growth effects in the rat model accumulated over a 10-day course.
Some users report subtle improvements in mental clarity or focus during this window. Difficult to attribute to Cortagen alone when stacking with other peptides. Effects are mild and not universally experienced.
Animal data suggests nerve regeneration effects peak toward the end of a 10-day treatment course. No human data exists for this period.
Minority of users report a modest sense of cognitive well-being toward the end of the course. No strong consensus signal exists: the community experience is too small to characterize reliably.
Khavinson theory holds that short peptide-induced epigenetic remodeling persists beyond active dosing. No longitudinal human data to confirm or deny duration of effect.
Users rarely report noticeable post-cycle persistence for Cortagen specifically. Unlike Epithalon's melatonin-mediated sleep effects, Cortagen has no identifiable subjective marker that users can track post-cycle.
Source: Estimated from general tetrapeptide kinetics; no formal PK studies published for Cortagen
Loading the interactive decay curve.
Cortagen is classified as a research-only compound. It has no FDA approval, no EMA approval, and no regulatory clearance from any Western health authority. In Russia, it has been used within the Khavinson bioregulator framework but does not hold formal drug registration equivalent to Western pharmaceutical approval. Cortagen is available through research peptide vendors (Peptide Sciences, Iron Mountain Labz, BioLongevity Labs). It is not a controlled substance and is not scheduled under the Controlled Substances Act. For athletes, no specific WADA ruling exists for Cortagen, but peptide bioregulators as a class face increasing scrutiny in tested competition. Most supply comes from research-grade vendors offering oral capsules (10 to 20 mg) or lyophilized injectable vials (10 mg). Pricing runs $40 to $70 for oral capsules and $30 to $50 for injectable vials. This content is for informational and research purposes only. It is not medical advice and should not replace consultation with a qualified healthcare provider. Peptide Schedule does not sell peptides or endorse specific vendors.
Peptide Schedule Research TeamReviewed Apr 20265 Citations
