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Prescription medication — not a dietary supplement
Cortexinis a prescription (or investigational) drug, not a supplement. It is included here for reference because people research and discuss it (often used off-label) — not as a recommendation. Take it only under a qualified clinician's supervision and only as prescribed; do not source it from grey-market vendors, where identity, purity, and dosing are unverified. The evidence below reflects its clinical trials.
What the evidence says
Most Cortexin studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from mixed-quality meta-analyses and randomised trials published 2016–2021.
Based on 7 studies · 1 meta-analysis
Confidence
ModerateBy outcome
The current evidence for Cortexin is insufficient to assign an evidence score, based on 7 indexed studies, including 1 meta-analysis. A low-molecular-weight polypeptide complex extracted from cattle/pig brain cortex, registered and very widely prescribed as a neuroprotective 'nootropic' medicine in Russia and CIS countries — so it has real (if mostly Russian-language and methodologically weak) human studies. Cortexin is given by intramuscular injection for stroke, cognitive impairment, epilepsy and pediatric neurology, with claimed neuroprotective and antioxidant effects mediated via glutamatergic/GABAergic activity. Animal work shows it crosses the blood-brain barrier and binds AMPA/kainate/GABA receptors. But the honest picture is sobering: in a rigorous double-blind rodent stroke comparison, cortexin was no better than saline (only cerebrolysin beat placebo), and Russian human trials are typically small, unblinded, single-center, and often show cortexin underperforming comparator drugs. It is NOT FDA-approved or a dietary supplement. Treat the neuroprotection claims as weakly evidenced. Representative study: PMID 36324709.
PT-141
Mostly mechanism / observationalA melanocortin-receptor (MC4R) agonist peptide for low sexual desire. Important honest framing: unlike most 'research peptides', bremelanotide is an FDA-APPROVED prescription drug — Vyleesi, approved 2019 — for acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women, self-injected subcutaneously on-demand. It has real phase-3 RCTs (the RECONNECT program). The catch: the approved-trial benefit was statistically significant but small (a fraction of a point on desire scales), nausea is very common, and it transiently raises blood pressure. Grey-market 'PT-141' vials sold online are NOT the approved drug and are unregulated.
Last reviewed June 2026 · evidence from 7 studies · how we score
This information is for educational purposes only. It is not a substitute for professional medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement or medication.
Cortexin (polypeptide cortex bioregulator)
A low-molecular-weight polypeptide complex extracted from cattle/pig brain cortex, registered and very widely prescribed as a neuroprotective 'nootropic' medicine in Russia and CIS countries — so it has real (if mostly Russian-language and methodologically weak) human studies. Cortexin is given by intramuscular injection for stroke, cognitive impairment, epilepsy and pediatric neurology, with claimed neuroprotective and antioxidant effects mediated via glutamatergic/GABAergic activity. Animal work shows it crosses the blood-brain barrier and binds AMPA/kainate/GABA receptors. But the honest picture is sobering: in a rigorous double-blind rodent stroke comparison, cortexin was no better than saline (only cerebrolysin beat placebo), and Russian human trials are typically small, unblinded, single-center, and often show cortexin underperforming comparator drugs. It is NOT FDA-approved or a dietary supplement. Treat the neuroprotection claims as weakly evidenced.
Scores a low Emerging 2 because, despite a plausible receptor mechanism, its human evidence is small unblinded Russian trials, it failed to beat saline in a rigorous animal study, and an independent meta-analysis found too few trials to pool.
Cortexin is a complex of low-molecular-weight (water-soluble) polypeptides and amino acids extracted by acetic-acid hydrolysis from the cerebral cortex of cattle (and pig) brain.
It is registered and extremely widely used as a neuroprotective/nootropic injectable medicine across Russia and the CIS, prescribed for ischemic stroke, traumatic brain injury, cognitive impairment, encephalopathy, epilepsy, and a broad range of pediatric neurological conditions.
Because it is a registered drug there, cortexin has a substantial — but methodologically weak and overwhelmingly Russian-language — clinical literature, which distinguishes it from grey-market research peptides with no human data.
Mechanistically, the best preclinical work comes from a 2021 PLoS ONE rodent study showing that radiolabeled cortexin crosses the blood-brain barrier (reaching 6-8% of whole-blood concentration) and that cortexin binds with high-to-moderate affinity to AMPA, kainate, mGluR1, mGluR5 and GABA-A receptors in vitro, suggesting its in-vivo effects in ischemia models may be glutamatergic/GABAergic; in that study cortexin reduced infarct necrosis, supported the antioxidant system, and improved neurological recovery in rats — comparable to cerebrolysin and better than actovegin.
However, the most rigorous, independent test is unflattering: in a prospective, randomized, double-blind, placebo-controlled rodent embolic-stroke study run at Henry Ford Hospital comparing four brain-hydrolysate preparations, cortexin produced functional outcomes and lesion volumes no different from saline, while only cerebrolysin significantly improved neurological recovery.
The Russian human trials are mostly small (typically 30-90 patients per arm), unblinded, single-center, and use surrogate or clinician-rated endpoints (NIHSS, MMSE, MoCA, Barthel index): some report faster regression of neurological and cognitive deficits when cortexin is added to standard stroke care or combined with mexidol, and a biomarker study reported falling NR2-peptide levels after a cortexin course — but in a head-to-head against Cellex, cortexin was the less effective agent on NIHSS and MMSE.
The honest assessment: cortexin is a real, registered, heavily-prescribed neuroprotective drug with a plausible receptor-level mechanism and demonstrable blood-brain-barrier penetration, but its clinical evidence is dominated by small, unblinded, single-country studies, it has failed to separate from placebo in the one rigorous independent animal comparison, it frequently underperforms comparator drugs, and an independent systematic review/meta-analysis of animal-derived nootropics found only a single eligible cortexin trial (80 patients) — too few to pool — and judged the supporting evidence weak and the effects probably below clinical relevance.
Western regulators have NOT approved it; it is neither an FDA-approved medicine nor a lawful dietary supplement; long-term safety beyond short injection courses is not well characterized; and it should be used only under a clinician in jurisdictions where it is registered.
In-vitro binding assays show cortexin binds with high-to-moderate affinity to AMPA, kainate, mGluR1, mGluR5 and GABA-A receptors. Its neuroprotective effects in animal ischemia models are attributed to this glutamatergic/GABAergic action — though the precise downstream mechanism in humans is not established.
Radiolabeled cortexin crossed the blood-brain barrier in mice, reaching 6-8% of whole-blood concentration in brain tissue — supporting the plausibility of a central effect after injection, a meaningful hurdle many peptide claims fail.
In rodent acute/chronic ischemia models, cortexin reduced the size of necrotic brain tissue, improved antioxidant-system function, and limited neurodegenerative changes. The proposed route from receptor activity to tissue protection — demonstrated in animals.
How Cortexin works — from molecular targets to health outcomes. Click an edge to see supporting research.This visualization is in beta — pathways are being refined and expanded.
Tap node to isolate • Pinch to zoom • Tap edge for research
Cortexin is a registered prescription neuroprotective drug in Russia/CIS, NOT a dietary supplement — this library does not provide a self-administration protocol. Where registered, it is given by intramuscular injection (commonly 10 mg/day, or 20 mg/day for adults, as a 10-day course), but any use must be directed by a clinician in a jurisdiction where it is approved.
Can be taken without food
| Form | Type |
|---|---|
| 🧪Lyophilized powder for intramuscular injection (registered drug where approved) | Recommended |
Cortexin is administered by injection. There is no validated oral supplement form; oral peptide would be digested.
Minimum: 1 weeks
Optimal: 2 weeks
Cycling: Not required
Note: Injectable prescription drug — timing follows the clinical dosing course, not supplement-style 'with food' or time-of-day rules.
Dose-response data unavailable. The current published research for Cortexin does not provide sufficient dose-specific outcome data to generate reliable dose-response curves.
Refer to the Dosage & Timing section above for recommended dose ranges based on available evidence.
Cortexin is a registered, very widely prescribed neuroprotective drug in Russia/CIS, so it has real human studies — but they are dominated by small, unblinded, single-center, Russian-language trials, often using surrogate endpoints. Critically, in a rigorous independent double-blind animal study cortexin was no better than saline, and in human head-to-heads it has underperformed comparator drugs. It is not FDA-approved or a dietary supplement.
In small Russian trials, adding cortexin to standard ischemic-stroke care (or combining with mexidol) was associated with faster regression of neurological deficits, cognitive scores (MMSE/MoCA) and post-stroke aphasia. Promising but unblinded and surrogate-based.
In a prospective, randomized, double-blind, placebo-controlled rodent embolic-stroke study, cortexin's functional outcomes and lesion volumes were no different from saline — only cerebrolysin beat placebo. A crucial honest counterweight to the positive Russian reports.
In a head-to-head human trial, cortexin was LESS effective than Cellex on NIHSS and MMSE; another analysis noted cortexin (unlike cerebrolysin) did not significantly improve neurological outcome over placebo in a rat model. Efficacy is inconsistent.
Cortexin crosses the blood-brain barrier and engages AMPA/kainate/GABA receptors, reducing ischemic necrosis and supporting antioxidant defenses in rodents — a genuine mechanistic basis, but one that has not translated into rigorous human-outcome proof.
Cortexin is reported well tolerated in short injection courses, but rigorous long-term safety data outside Russia/CIS practice are lacking, and grey-market 'research peptide' material has no quality control.
Avoid — safety in pregnancy and lactation is not established.
Cortexin is widely used in pediatric neurology in Russia/CIS, but that use rests on weak evidence; any pediatric use must be specialist-directed, never self-administered.
Avoid unregulated sources — identity, purity and sterility are not guaranteed (and the source tissue is animal brain); a registered pharmaceutical product under clinical care is the only defensible route.
Cortexin is frequently combined with other neuroprotectives (e.g. mexidol) in Russian practice; net effects of such combinations are not rigorously studied and should be clinician-directed.
Cortexin binds AMPA/kainate/GABA receptors in vitro; theoretical additive effects with other glutamatergic/GABAergic drugs have not been studied and warrant clinical caution.
Tip: Administer per clinical protocol; cortexin is reported to be generally well tolerated in short courses.
Tip: Stop and seek care if an allergic reaction occurs.
Tip: Long-term safety outside studied short courses is poorly characterized; do not self-administer chronically.
The commonly studied dose of Cortexin is Cortexin is a registered prescription neuroprotective drug in Russia/CIS, NOT a dietary supplement — this library does not provide a self-administration protocol. Where registered, it is given by intramuscular injection (commonly 10 mg/day, or 20 mg/day for adults, as a 10-day course), but any use must be directed by a clinician in a jurisdiction where it is approved.. Individual needs vary — start at the lower end of the range and adjust based on how you respond.
Timing is flexible for Cortexin — consistent daily use matters more than the time of day. Cortexin is injected intramuscularly and dosed as a fixed daily course; timing follows the clinical protocol rather than food or circadian considerations.
Cortexin should be used with caution — talk to a healthcare provider before taking it. The most commonly reported side effects are injection-related reactions, hypersensitivity to brain-derived peptide material, unknown long-term effects. Use caution if any of these apply to you: Not an FDA-approved drug or a regulated dietary supplement — registered as a prescription neuroprotective drug only in Russia/CIS; use only under a clinician; Known hypersensitivity to cortexin or to bovine/porcine brain-derived peptide preparations; Pregnancy and breastfeeding (not established as safe).
Gonadorelin
Mostly mechanism / observationalA synthetic copy of gonadotropin-releasing hormone (GnRH), the hypothalamic decapeptide that drives the pituitary to release LH and FSH. Honest appraisal: it has genuine, trial-backed roles as a diagnostic agent (the GnRH/gonadorelin stimulation test) and — delivered in pulses by an infusion pump — for inducing ovulation in hypothalamic amenorrhea and spermatogenesis in men with congenital hypogonadotropic hypogonadism. Its now-trendy use in men's TRT clinics (compounded, to 'maintain testosterone/fertility' alongside testosterone, often replacing hCG) is largely off-label and has NOT been validated in controlled trials for that purpose.