What is the difference between Cortexin and Semax?

Cortexin: Polypeptide bioregulator from bovine cortex; modulates neurotransmitter activity; activates GABA and dopamine systems; reduces excitotoxicity; stimulates neuronal repair Semax: Semax is believed to upregulate brain-derived neurotrophic factor (BDNF) and other neuroprotective factors, enhancing neuronal survival and synaptic plasticity.

Is Cortexin FDA approved?

Cortexin is not evaluated or approved by the FDA. It is discussed for research and educational purposes only, not as medical guidance.

Is Semax FDA approved?

Semax is the subject of a favorable FDA advisory committee vote but not FDA approved, and its legal status for compounding is unchanged. It is discussed for research and educational purposes only, not as medical guidance.

How is Cortexin administered in research settings?

In research settings, Cortexin is typically administered via the intramuscular route. PeptideBase does not provide dosing or administration instructions.

How is Semax administered in research settings?

In research settings, Semax is typically administered via the intranasal or subcutaneous routes. PeptideBase does not provide dosing or administration instructions.

Home›Research›Compare›Cortexin vs Semax

Peptide Comparison

Cortexin vs Semax

Name: Cortexin vs Semax — Per-mg Price Comparison
Creator: PeptideBase
License: https://peptidebase.io/terms

Both are Neuro & Cognitive peptides.

Cortexin

Cortexin-10

CognitiveNot EvaluatedResearch Only

Half-life: Unknown

4 providers listed

Full Cortexin profile →

Semax

ACTH(4-10) analogue

CognitiveAdvisory Vote: FavorableResearch Only

Half-life: 20–30 minutes (intranasal)

168 providers listed

Full Semax profile →

Bottom line

Cortexin has published research citations on file; Semax does not yet — the main evidence gap between them.

Quick Verdict

Cortexin

Half-life

Unknown

Semax

Half-life

20–30 minutes (intranasal)

Which One Should You Choose?

Your goal	Better option
Has published research citations	Cortexin
More provider options (4 vs 168)	Semax

Research summary only — not medical advice. Consult a qualified provider before making any decisions.

Side-by-Side Comparison

Cortexin

Semax

Mechanism Family

Neuro & Cognitive

Half-life

Unknown

20–30 minutes (intranasal)

FDA Status

not evaluated

advisory committee recommended

Admin Routes

intramuscular

intranasal, subcutaneous

Availability

Research Only

Providers

4 listed

168 listed

FDA Update

—

Jul 2026

Avail. Notes

Russian polypeptide preparation from cattle cerebral cortex. Registered in Russia for neurological conditions. No FDA approval, no NDA or IND, not on any FDA list. Research chemical in US.

Russian ACTH 4-7 neuropeptide analog. Approved pharmaceutical nasal spray in Russia. Not FDA-approved. Not on FDA 503A bulks list. Unscheduled in US. Sold as research chemical.

Research Evidence

Cortexin

Review · 1 key study · dated evidence base — most recent 2013

Semax

No citations on file

Research Citations

Cortexin

Review2013 · Advances in gerontology

Neuroprotective effects of peptides bioregulators in people of various age

Semax

No citations on file.

About Cortexin

Polypeptide bioregulator from bovine cortex; modulates neurotransmitter activity; activates GABA and dopamine systems; reduces excitotoxicity; stimulates neuronal repair

Research Areas

neuroprotection and neuronal survival supportcognitive function improvement — documented in Russian clinical settingsantioxidant activity in CNS tissueEEG normalization and neurotrophic factor expression

About Semax

Semax is believed to upregulate brain-derived neurotrophic factor (BDNF) and other neuroprotective factors, enhancing neuronal survival and synaptic plasticity. It modulates the dopaminergic and serotonergic systems, contributing to its reported effects on mood and focus. Its mechanism of action differs from classical stimulants — it does not act on adrenergic receptors and does not produce typical stimulant tolerance or dependence patterns.

Research Areas

BDNF and VEGF upregulation supporting neuroplasticityneuroprotection and stroke recovery — Russian clinical approvalcognitive performance and focus enhancement via dopaminergic modulationnasal spray administration — CNS access via olfactory epithelium

Safety Profile

Information below reflects published research data only — not medical advice. Consult a qualified provider before use.

Cortexin

Reported (Unverified — Pending Clinical Review)

bovine protein allergy

No established clinical contraindications

Semax

No established clinical contraindications. This is an investigational compound with limited human data and has not been evaluated by the FDA for safety in this context. Consult a qualified clinician.

Used Together?

Semax

Selank
Research suggests Semax and Selank may produce complementary cognitive and stress-modulating effects when combined. Semax is studied for BDNF upregulation and cognitive enhancement, while Selank is studied for anxiolytic and immune-regulatory activity — distinct mechanisms with potential overlap in neuroprotective signaling.

Price (per mg)

Cortexin

Not enough vendor pricing yet.

Semax

$4.37/mg

$3.52 – $5.50 range

45 vendors

View price index →Find providers →

Find Providers

Where to source these peptides

Providers offering

Cortexin

4 listed

Browse directory →

Providers offering

Semax

168 listed

Browse directory →

PeptideBase lists providers for educational research purposes only. Always consult a qualified healthcare professional before obtaining or using any peptide.

More Neuro & Cognitive Comparisons

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Educational research tools — not medical advice.

Cite this page

Data last updated August 26, 2026

Free to reference and republish with attribution to PeptideBase. Choose a format:

PeptideBase. (2026). Cortexin vs Semax — Per-mg Price Comparison. Retrieved September 11, 2026, from https://peptidebase.io/peptides/compare/cortexin/semax

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