What Is Semax?
Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic heptapeptide developed during the 1980s at the Institute of Molecular Genetics of the Russian Academy of Sciences as a stabilized version of the ACTH 4-10 fragment. The Pro-Gly-Pro C-terminal extension confers resistance against enzymatic breakdown while preserving the parent sequence's neurotropic properties. Unlike native ACTH, Semax lacks the receptor-binding domains that trigger adrenal cortisol release — eliminating confounding endocrine effects in CNS research designs. Molecular weight is approximately 887 g/mol.
Research Applications
Neurotrophin Modulation: Studies document increased BDNF (brain-derived neurotrophic factor) and TrkB receptor expression in hippocampal tissue following intranasal administration in rodent models. BDNF is the primary growth factor supporting neuronal survival, synaptic plasticity, and adult neurogenesis; upregulation in hippocampal regions is of broad interest in memory and neuroprotection research.
Monoamine Signaling: Evidence from rodent studies indicates influence on dopamine and serotonin turnover in attention-related brain regions, particularly the prefrontal cortex and striatum. The ACTH 4-10 core sequence has a research history in attention and arousal modulation, and Semax's stabilized form extends this investigation profile.
Neuroprotection: Extensive research programs in Russian academic and clinical settings examined ischemia models, inflammatory marker responses, and neuronal survival pathways. Published studies used middle cerebral artery occlusion (MCAo) models in rats and mice, examining infarct volume, neurological deficit scoring, and biomarker changes. Behavioral models including Morris water maze and passive avoidance paradigms appear across the published literature.
Cognitive Neuroscience Models: Semax has been investigated in cognitive impairment models including age-related decline paradigms, hypoxic stress models, and chemical-induced amnesia (scopolamine) designs in rodents.
Administration Route
Intranasal delivery predominates in published protocols. Direct CNS access via olfactory and trigeminal nerve pathways allows Semax to bypass the blood-brain barrier and gastrointestinal degradation. This route is pharmacologically distinct from parenteral administration and is methodologically significant — intranasal delivery affects both local nasal tissue and CNS compartments, requiring careful experimental design to distinguish peripheral from central effects.
In vitro and preclinical injection-based research (intraperitoneal, subcutaneous) also appears in the literature, though the intranasal route is the most clinically translatable and most thoroughly studied for CNS endpoints.
Semax vs. Selank
Researchers occasionally compare Semax with Selank (another ACTH-derived peptide developed at the Institute of Molecular Genetics). Key distinctions:
| Property | Semax | Selank |
|---|---|---|
| Sequence | ACTH 4-10 + Pro-Gly-Pro | Tuftsin (Thr-Lys-Pro-Arg) + Gly-Pro-Pro |
| Primary research focus | BDNF upregulation, neuroprotection | Anxiolytic, immune modulation |
| Monoamine effects | Dopamine/serotonin | Primarily GABA/serotonin |
| Molecular weight | ~887 g/mol | ~863 g/mol |
Both peptides share research chemical status in Canada and the same intranasal delivery profile. Some researchers combine them in study designs examining overlapping neurological pathways.
Quality Standards for Research-Grade Semax
Semax is a relatively small heptapeptide with a straightforward synthesis profile, but quality still varies considerably across suppliers. Key verification criteria:
- HPLC purity: ≥98% minimum; ≥99% preferred for sensitive neurological research assays where trace impurities could affect receptor binding or cellular toxicity measurements
- Mass spectrometry: Confirm observed molecular weight at approximately 887 Da (±0.5 Da tolerance for standard instruments)
- Counterion specification: Semax is commonly supplied as acetate salt; the COA should specify the salt form, as this affects accurate mass calculation
- Sterility documentation: Particularly important for preparations intended for intranasal application in animal studies, where nasal mucosal contact occurs directly
Third-party independent laboratory verification is the gold standard. Avoid suppliers providing only manufacturer-internal testing documentation, as the absence of independent verification creates an inherent conflict of interest in quality reporting.
Formulation Considerations
Semax is available in two primary research forms:
Lyophilized powder: Requires reconstitution before use. Reconstitutes readily in sterile saline, BAC water, or sterile water for injection. For intranasal delivery in animal studies, isotonic saline is the standard vehicle (to match nasal mucosal tonicity and minimize tissue irritation). Stable for 28–30 days reconstituted at 2–8°C.
Pre-formulated nasal spray solution: Some suppliers provide Semax in aqueous nasal spray formulations at specified concentrations (commonly 0.1% or 1% = 1 mg/mL or 10 mg/mL). Pre-formulated solutions are convenient for studies requiring standardized delivery volumes but have shorter shelf lives than lyophilized powder; storage at 2–8°C in opaque containers is required.
Sourcing in Canada
Semax is available from select Canadian research chemical suppliers. It occupies a smaller commercial niche than BPC-157 or metabolic peptides, so domestic availability is more limited. When sourcing:
- Confirm the specific form available (lyophilized vs. pre-formulated)
- Verify the salt form (acetate is standard) in documentation
- Request batch-specific COA rather than generic product documentation
- For nasal spray formulations, confirm pH and tonicity specifications are documented
Pricing in the Canadian market ranges approximately CAD $60–$100 for 30 mg of lyophilized research-grade Semax with third-party COA documentation.
Canadian Research Status
Semax is unapproved by Health Canada and the FDA for human therapeutic use. It is available as a research-only chemical for qualified in vitro and preclinical laboratory investigation. It is not scheduled under the Controlled Drugs and Substances Act and does not require a special research license for procurement in Canada. Semax is clinically approved and commercially available as a nasal spray in Russia for neurological indications, but this approval has no legal standing in the Canadian context.
Frequently Asked Questions
What is Semax? Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic heptapeptide developed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a stabilized version of the ACTH 4-10 fragment. Its Pro-Gly-Pro extension resists enzymatic breakdown while preserving neurotropic properties. Molecular weight is approximately 887 g/mol.
How is Semax administered in research? Intranasal delivery predominates in published protocols, providing direct CNS access via olfactory and trigeminal nerve pathways that bypass the blood-brain barrier and gastrointestinal degradation. Injection-based routes (intraperitoneal, subcutaneous) also appear in the literature, but intranasal is the most thoroughly studied for CNS endpoints.
How does Semax differ from Selank? Both are peptides developed at the same institute and share intranasal delivery. Semax (ACTH 4-10 plus Pro-Gly-Pro, ~887 g/mol) is studied mainly for BDNF upregulation and neuroprotection with dopamine and serotonin effects, while Selank is focused on anxiolytic and immune-modulation research through GABA and serotonin pathways.
Is Semax legal as a research chemical in Canada? Semax is unapproved by Health Canada and the FDA for human therapeutic use but is available as a research-only chemical for qualified in vitro and preclinical investigation. It is not scheduled under the Controlled Drugs and Substances Act and requires no special research license to procure in Canada.
Research Disclaimer
Semax is not approved by Health Canada or any regulatory authority for human or veterinary therapeutic use in Canada. All research applications are exclusively in vitro or preclinical. This content is for informational purposes only and does not constitute medical advice.