Synthetic heptapeptide derived from ACTH(4-10), researched for neuroprotection, cognitive enhancement, and brain injury recovery. Approved in Russia as a nootropic.
Last Updated: May 2026
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) derived from a fragment of adrenocorticotropic hormone (ACTH 4-10), approved in Russia as a nootropic and neuroprotective agent and used clinically for stroke recovery, cognitive impairment, and ischemic brain injury. It is one of the longest-clinically-used peptides in the Russian medical system and has substantial post-market clinical experience but limited Western RCT replication. Important regulatory update: Semax was removed from the FDA's Category 2 bulk substances list on April 22, 2026 and is scheduled for Pharmacy Compounding Advisory Committee (PCAC) review in July 2026.
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) derived from the ACTH(4-10) fragment with N-terminal modifications for stability and intranasal bioavailability, proposed to act through multiple mechanisms: BDNF (brain-derived neurotrophic factor) upregulation, melanocortin receptor modulation, neurotransmitter system effects (dopaminergic, serotonergic), and direct neuroprotective effects against ischemic injury. The intranasal route allows direct nose-to-brain delivery, bypassing the blood-brain barrier and limiting systemic exposure. Evidence level: Approved in Russia (stroke, cognitive disorders); preclinical extensive (neuroprotection, BDNF); Western Phase 2/3 RCT limited.
Russian clinical practice has used Semax for ischemic stroke recovery, transient ischemic attack, cognitive impairment, and ADHD in pediatric populations, with substantial post-market clinical experience accumulated over 30+ years. Preclinical studies have shown BDNF upregulation, neuroprotection in stroke models, and effects on cognitive performance markers in rodents. Western-standard Phase 2/3 RCT data is limited; the strongest evidence base comes from Russian clinical use rather than blinded controlled trials. Evidence level: Russian clinical (approved use, decades of practice); preclinical extensive; Western RCT limited.
Semax sits in the Russian-developed cognitive peptide cluster alongside Selank (anxiolytic) and N-Acetyl Semax Amidate (extended-stability Semax analog), distinguished by its primary cognitive enhancement and neuroprotection positioning.
| Compound | Mechanism | Primary effect | Approved status |
|---|---|---|---|
| Semax | ACTH(4-10), BDNF upregulation | Cognitive, neuroprotection | Approved in Russia |
| N-Acetyl Semax Amidate | Acetylated/amidated Semax analog | Cognitive (longer half-life) | Not approved (research) |
| Selank | Tuftsin-derived, GABA/serotonin | Anxiolytic, cognitive | Approved in Russia |
| P21 | CNTF-derived, neurogenesis | Neurogenic | Preclinical only |
Side effects in Russian clinical use are generally mild — occasional mild irritation of nasal mucosa with intranasal administration, transient headache, and rare reports of mild stimulation effects. The favorable safety profile is consistent with the ACTH-fragment origin and intranasal delivery limiting systemic exposure. Long-term safety has been observed in Russian clinical practice over decades with the caveats that apply to non-blinded clinical use. Evidence level: Russian clinical safety record (decades); Western RCT safety data limited.
Semax is approved for medical use in Russia for ischemic stroke recovery, transient ischemic attack, and cognitive disorders, but is not approved by the FDA, EMA, or other major Western regulators. On April 22, 2026, Semax was removed from the FDA's Category 2 bulk substances list and is scheduled for Pharmacy Compounding Advisory Committee (PCAC) review in July 2026. Removal from Category 2 does not authorize compounding — formal Category 1 inclusion or 503A bulks list addition remains pending PCAC determination. Current status in FDA peptide regulation 2025–2026 timeline.
Semax synthesis is mature and widely available in the research-grade market, but the structural similarity between Semax (Met-Glu-His-Phe-Pro-Gly-Pro) and N-Acetyl Semax Amidate (Ac-Met-Glu-His-Phe-Pro-Gly-Pro-NH₂) creates mislabeling risk — vendors occasionally sell one as the other. Mass spectrometry identity confirmation distinguishes the two definitively. Intranasal formulations have additional stability and excipient considerations not addressed by basic peptide HPLC. Guidance in how-to-test-peptides hub.
Peptigrity purchases Semax vials anonymously at standard customer pricing, sends them to ISO-accredited third-party labs for HPLC and mass spectrometry analysis, and publishes the unedited certificate of analysis. The lab test table above this section shows the cross-shop dataset. Tests come from labs including Janoshik Analytical, Freedom Diagnostics, and Chromate. Methodology in how we calculate trust scores.
Semax is researched and clinically used in Russia for cognitive enhancement, ischemic stroke recovery, and neuroprotection, with proposed mechanisms including BDNF upregulation and effects on multiple neurotransmitter systems. Russian clinical evidence base is substantial; Western Phase 2/3 RCT evidence is more limited.
Semax is approved for medical use in Russia and is legal to purchase as a research chemical for laboratory use in most other jurisdictions, but it is not approved for human consumption in the US, EU, or most Western markets. The April 22, 2026 Category 2 removal opens a potential future compounding pathway pending PCAC review in July 2026. Country breakdown in peptide legal status guide.
Semax is scheduled for Pharmacy Compounding Advisory Committee (PCAC) review in July 2026. The PCAC will evaluate historical safety data and clinical utility to make a recommendation on whether Semax should be added to the 503A bulks list. Track developments in FDA peptide regulation 2025–2026 timeline.
N-Acetyl Semax Amidate is Semax with N-terminal acetylation and C-terminal amidation modifications that extend half-life and improve bioavailability. They are different molecules with related effects; the modified analog has longer activity per dose. Some research-grade vendors sell one mislabeled as the other.
Independent third-party HPLC certificate of analysis from a lab the vendor does not own or pay, with mass spectrometry identity confirmation. Mass spec is essential to distinguish Semax from N-Acetyl Semax Amidate and from related ACTH-fragment peptides. COA interpretation in red flags in peptide certificates of analysis.
No. Peptigrity is an independent review platform, not a medical authority. Russian clinical protocols for stroke recovery and cognitive indications vary; intranasal dosing is the primary clinical route. Anyone considering Semax use should consult a licensed physician.
This section is for educational and informational purposes only and does not constitute medical advice. Semax is approved for medical use in Russia but is not approved by the FDA or other major Western regulators. It was removed from Category 2 of the FDA 503A bulk substances list in April 2026 and is scheduled for PCAC review in July 2026. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.
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