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Cortexin

Brain & Focus

Calf cortex peptide complex

Cortexin is a polypeptide complex derived from the cerebral cortex tissue of young cattle or pigs, used primarily as a neuroprotective agent in Russia.

§Dosing at a glance

5 protocols · from the research
What it's forDoseHow oftenHowFor how long
Acute Ischemic Stroke (Adults)10 mgTwice dailyIntravenousInjected directly into a vein.10 days
Chronic Cerebral Ischemia (Adults)10 mgOnce dailyIntramuscularInjected into a muscle.6 mos
Diabetic Neurological Complications (Adults)10 mgOnce dailyIntramuscularInjected into a muscle.—
Depression (Adults, Add-on Therapy)10 mgOnce dailyIntramuscularInjected into a muscle.10 days
Animal Model Reference Doses (preclinical only)1–3 mg/kg/dayDailyIntramuscularInjected into a muscle.10 days

Approximate values pulled from the research — double-check before dosing.

§01Summary

Cortexin is a polypeptide complex derived from the cerebral cortex tissue of young cattle or pigs, used primarily as a neuroprotective agent in Russia and other post-Soviet countries. It contains a mixture of low-molecular-weight neuropeptides, amino acids, and neurotrophic factors that are thought to support brain cell survival, reduce neurological damage, and promote cognitive recovery. In clinical use, Cortexin has been studied most extensively in stroke recovery, where it may improve neurological function and cognitive outcomes1,4. It has also been investigated in chronic cerebral ischemia, where it has been reported to reduce symptom severity and fatigue in a dose-dependent manner3. Emerging research suggests it may benefit patients with diabetic neurological complications5 and children with neurodevelopmental conditions including ADHD and speech delay16. Preclinical studies demonstrate that Cortexin crosses the blood-brain barrier and interacts with multiple receptor systems involved in brain protection11. The drug is administered by injection rather than orally, and treatment typically involves short courses of daily injections. While Cortexin is widely prescribed in its home markets, the global evidence base is actively developing, with most published data originating from Russian-language literature and research groups.

This is the layperson summary. Mechanism, dosing, the evidence base, and the published literature are in the sections below — every claim links to its source.

§02In depth

Cortexin is a multicomponent polypeptide hydrolysate prepared from the cerebral cortex of young cattle or pigs through acid extraction and ultrafiltration. The final preparation contains a heterogeneous mixture of low-molecular-weight peptides (molecular weight typically below 10 kDa), free amino acids, and small quantities of neurotrophic factors. Because it is an extract rather than a defined molecular entity, its precise composition is not fully standardized, complicating mechanistic attribution.

Pharmacologically, Cortexin has been shown to cross the blood-brain barrier in vivo at approximately 6–8% of circulating blood concentrations11, establishing meaningful CNS exposure. In vitro receptor binding studies identified significant affinity for AMPA receptors (80.1% binding), kainate receptors (73.5%), metabotropic glutamate receptor 1 (mGluR1; 49.0%), GABA-A receptors (44.0%), and mGluR5 (39.7%)11. This receptor profile indicates that Cortexin peptides modulate both ionotropic and metabotropic glutamatergic neurotransmission as well as GABAergic inhibitory signaling — pathways directly implicated in excitotoxic neuronal death following ischemic injury.

At the molecular level, Cortexin peptides have been identified to interact with neuron-specific proteins including β5-tubulin, creatine kinase B, and 14-3-3 α/β20. These interactions are proposed to influence cytoskeletal organization, neuronal energy metabolism, and intracellular signal transduction respectively. In brain tissue specifically, Cortexin tissue-selectively inhibits caspase-820, suggesting a targeted anti-apoptotic mechanism distinct from non-specific protease inhibition. In accelerated aging animal models, Cortexin restores the pro/antioxidative balance and exerts anti-inflammatory effects both centrally and systemically20.

Biochemical studies in humans with chronic cerebral ischemia confirmed antioxidant activity through increased superoxide dismutase activity and SH-group content at both 10 mg and 20 mg doses3, suggesting this mechanism is operative at clinically used dosing levels. Cognitive and neuroprotective effects in rodent chronic ischemia models were not accompanied by significant changes in cerebral blood flow as measured by laser flowmetry18, indicating that the dominant mechanism is direct neuroprotection rather than hemodynamic modulation. Neuroendocrine studies in patients with asthenic disorders suggest that Cortexin may additionally modulate the hypothalamic-pituitary axis, with reported normalization of cortisol, DHEA-S, and thyroid hormone levels8, though the mechanistic basis for this systemic neuroendocrine influence requires further characterization in dedicated studies.

§04Evidence & efficacy

Evidence base
216Studies
103Human
35Animal

Cortexin's most studied indication is acute ischemic stroke. In a recent therapeutic equivalence RCT, both intravenous and intramuscular formulations produced favorable functional outcomes (mRS 0–2) in 93.64% and 86.50% of patients respectively at day 90, with NIHSS scores improving by approximately 3.9 points and MMSE scores by approximately 4 points1. An earlier placebo-controlled study reported improvements in NIHSS, modified Rankin Scale, and Barthel Index scores in patients treated with 20 mg daily for 10 days7. A multicenter RCT found that two 10-day courses of Cortexin produced superior outcomes compared to one course or placebo in acute stroke patients4.

In chronic cerebral ischemia, Cortexin has been reported to produce dose-dependent improvements in neurological symptom severity, fatigue, and sleep disturbance, with the 20 mg dose showing superior results3. Antioxidant effects, reflected in superoxide dismutase activity and SH-group content, were observed at both dose levels3.

In diabetic neurological complications, Cortexin addition to standard therapy has been reported to produce substantially greater improvements in cognitive function (MoCA), anxiety-depression symptoms (HADS), and peripheral neuropathy scores (NTSS-9) compared to active control treatment, with 83.3% of Cortexin patients demonstrating good or very good global clinical improvement5.

In children with neurodevelopmental conditions, Cortexin has been reported to improve attention, visual memory, and cognitive processing across diagnostic groups including ADHD and speech delay, with the strongest response observed in children aged 3–4 years16. In neonates and infants with hypoxic CNS injury, two Cortexin courses appeared to reduce myotonic and hypertensive-hydrocephalic syndrome frequency and normalize EEG bioelectric activity in approximately 71–73% of treated patients9.

For depression, preliminary evidence suggests that Cortexin added to antidepressant therapy may improve depression severity scores (MADRS) and social functioning (SASS) compared to antidepressant monotherapy alone13.

In preclinical rodent ischemia models, Cortexin at 1–3 mg/kg improved cognitive performance across multiple behavioral paradigms, reduced hippocampal pathomorphological changes, and showed durable benefit following a treatment break11,18. However, a separate blinded comparative animal study found no significant improvement in neurological outcome or infarct volume with Cortexin versus saline control at a dose adapted from label recommendations12.

A systematic review and meta-analysis identified only a single eligible Cortexin RCT (n=80) for cognitive disorders, limiting pooled analysis, though narrative findings suggested potential efficacy with no safety concerns6.

§05Safety

Cortexin has demonstrated an acceptable tolerability profile across the human studies published to date. In the largest and most rigorously reported RCT, the intravenous formulation was associated with 74 adverse events across 60 patients and the intramuscular formulation with 51 adverse events across 41 patients, with no statistically significant difference between routes (p>0.05)1. In the diabetic neurological complications trial, only 5 adverse events total were recorded across both treatment arms, with none attributed to the study drug5. In the depression add-on study, the Cortexin combination group reported fewer adverse events on the UKU Side Effect Rating Scale than antidepressant monotherapy at day 28 (p=0.001)13. Across pediatric studies, tolerability was reported as good with no specific adverse events described9,16.

A relevant safety signal for the broader drug class comes from a Cochrane systematic review that included Cortexin as a Cerebrolysin-like agent: moderate-certainty evidence identified a potential increase in non-fatal serious adverse events with Cerebrolysin use (RR 2.39, 95% CI 1.10–5.23), most pronounced at higher cumulative doses (RR 2.87, 95% CI 1.24–6.69)2. Whether this signal extends to Cortexin at its typical lower cumulative doses is an area of active investigation.

No drug interactions, specific contraindications, or organ toxicity findings were reported across the reviewed studies. No serious treatment-related adverse events attributable to Cortexin were identified in any individual trial.

§06History

The endogenous cortexin protein was first characterized in 1993 as a novel 82-amino acid integral membrane protein expressed specifically in neurons of the rodent cerebral cortex, with expression present in fetal brain and peaking postnatally15. This molecular characterization established the biological relevance of cortical peptide fractions to neurodevelopment and adult cortical function.

The pharmaceutical preparation Cortexin — a polypeptide extract derived from bovine or porcine cerebral cortex — was developed in Russia and has been manufactured commercially since the 1980s and 1990s. It was registered for clinical use in Russia and several post-Soviet states as a neuroprotective agent for neurological and psychiatric conditions. Early clinical application focused on ischemic stroke and chronic cerebrovascular insufficiency, with the drug incorporated into Russian neurological treatment guidelines.

Systematic clinical research began to accumulate in the 2000s, with early placebo-controlled studies in acute ischemic stroke demonstrating improvements in neurological deficit scales7. A multicenter RCT evaluating dosing regimens in acute stroke was published in 20144, followed by a multicenter dose-comparison study in chronic cerebral ischemia in 20183. Animal mechanistic studies through the 2010s and early 2020s characterized receptor binding profiles and molecular targets11,20. As of 2023–2025, research has expanded into diabetic neurological complications5 and psychiatric indications13, with the first direct comparison of intravenous versus intramuscular formulations published in 20251. Cortexin remains primarily used and studied in Russia and Eastern Europe, with its evidence base continuing to develop in the international literature.

§07References