What is the difference between Cortexin and Met-Enkephalin?

Cortexin: Polypeptide bioregulator from bovine cortex; modulates neurotransmitter activity; activates GABA and dopamine systems; reduces excitotoxicity; stimulates neuronal repair Met-Enkephalin: Binds OGF receptors (zeta opioid receptors) on cell nuclei, regulating DNA synthesis and cell proliferation in a tonic inhibitory manner. Also binds delta opioid receptors.

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 Met-Enkephalin FDA approved?

Met-Enkephalin is not evaluated or approved by the FDA. 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 Met-Enkephalin administered in research settings?

In research settings, Met-Enkephalin is typically administered via the subcutaneous or intravenous routes. PeptideBase does not provide dosing or administration instructions.

Home›Research›Compare›Cortexin vs Met-Enkephalin

Peptide Comparison

Cortexin vs Met-Enkephalin

Both are Neuro & Cognitive peptides.

Cortexin

Cortexin-10

CognitiveNot EvaluatedResearch Only

Half-life: Unknown

4 providers listed

Full Cortexin profile →

Met-Enkephalin

Methionine enkephalin

RecoveryNot EvaluatedResearch Only

5 providers listed

Full Met-Enkephalin profile →

Bottom line

Cortexin carries stronger published evidence (RCT, 2 key studies) than Met-Enkephalin (Cohort study, 4); both are research compounds.

Quick Verdict

Cortexin

Evidence

Emerging Clinical

Met-Enkephalin

Evidence

Observational

Which One Should You Choose?

Your goal	Better option
Stronger clinical evidence	Cortexin
More provider options (4 vs 5)	Met-Enkephalin

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

Side-by-Side Comparison

Cortexin

Met-Enkephalin

Mechanism Family

Neuro & Cognitive

Half-life

Unknown

—

FDA Status

not evaluated

Admin Routes

intramuscular

subcutaneous, intravenous

Availability

Research Only

Providers

4 listed

5 listed

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.

—

Research Evidence

Cortexin

Emerging ClinicalRCT · 2 key studies · most recent 2019

Met-Enkephalin

ObservationalCohort study · 4 key studies · most recent 2026

Research Citations

Cortexin

RCT2019 · Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova

Evaluation of the efficacy and safety of cortexin in the complex rehabilitation of verticalization in patient…

Review2013 · Advances in gerontology

Neuroprotective effects of peptides bioregulators in people of various age

Met-Enkephalin

Cohort2026 · Psychoneuroendocrinology

Endogenous opioid peptides in trichotillomania: An exploratory analysis of focused and automatic hair-pulling…

Cohort2026 · J Photochem Photobiol B

Unraveling the role of iodide in photosensitized oxidation of Met-Enkephalin.

Review2015 · Biochemical Pharmacology

Duration of opioid receptor blockade determines biotherapeutic response

Review2012 · Biochemical Pharmacology

The opioid growth factor-opioid growth factor receptor axis: homeostatic regulator of cell proliferation and…

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 Met-Enkephalin

Binds OGF receptors (zeta opioid receptors) on cell nuclei, regulating DNA synthesis and cell proliferation in a tonic inhibitory manner. Also binds delta opioid receptors. Intermittent blockade by low-dose naltrexone upregulates receptor expression and endogenous MENK tone.

Research Areas

immune modulationcell proliferation regulationanti-inflammatoryautoimmune support

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

Met-Enkephalin

Absolute Contraindications

Under clinical review

Being verified by our medical team before we display contraindications for this peptide.

Find Providers

Where to source these peptides

Providers offering

Cortexin

4 listed

Browse directory →

Providers offering

Met-Enkephalin

5 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

Browse all peptides →

Educational research tools — not medical advice.