Semax
ACTH 4-10 analog · cognitive research peptide
Overview
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) derived from the central fragment of adrenocorticotropic hormone (ACTH 4-10), with a C-terminal Pro-Gly-Pro extension that protects the molecule from peptidase cleavage and produces a substantially longer functional half-life than the parent ACTH fragment. Developed in the 1980s at the Institute of Molecular Genetics in Moscow, Semax is approved in Russia as a prescription medication for cerebrovascular and cognitive indications, though it is unapproved in the US and EU. The molecule is studied in research contexts for BDNF expression modulation, neuroprotection, working memory, and attention-related applications. Lyochem supplies Semax acetate as a lyophilized powder at ≥99.0% HPLC. The dominant administration route in the published research literature is intranasal, Semax is not blood-brain-barrier permeable when delivered systemically in any practical quantity, and the intranasal route allows direct olfactory and respiratory-epithelium absorption. Buyers preparing intranasal formulations should select isotonic carrier vehicles (saline or PBS rather than plain water) and avoid preservatives like benzalkonium chloride that interact with short peptides. Standard 2-15 mg fill sizes cover both research and compounding pharmacy dispensing scales.
Who buys this, and why
Cognitive and neuropeptide buyers are predominantly research labs running in vivo rodent studies. The dominant administration route in the published literature is intranasal — Semax, Selank, DSIP, Pinealon — because these peptides are not meaningfully blood-brain-barrier permeable when delivered systemically. For in vivo workflows, endotoxin and microbial-limit testing is recommended at the CoA stage so the bioassay readout is not confounded by contamination unrelated to the test article.
Primary buyer fit: academic and contract research laboratories and research laboratories that have validated this peptide into their workflow.
Specifications
- CAS
- 80714-61-0
- Sequence
- MEHFPGP
- Purity (HPLC)
- ≥ 99.0%
- Common vial sizes
- 2 mg, 5 mg, 10 mg, 15 mg
- MOQ
- On request
- Lead time
- 7–14 days
- Storage
- -20°C, protect from light
Documentation available on request
- Lot-specific Certificate of Analysis (CoA)
- RP-HPLC chromatogram with peak integration
- ESI-MS identity confirmation (±0.5 Da)
- Sequence verification by LC-MS/MS
- Water content by Karl Fischer
- SDS / MSDS
- Bacterial endotoxin (LAL) on request — in vivo workflows
- Intranasal-formulation reconstitution guidance
- Sequence ladder (full b/y-ion) on request
Regulatory note
Approved as a prescription medication in Russia for cerebrovascular and cognitive indications; unapproved in US and EU. Currently under FDA PCAC review (July 2026) for inclusion on the 503A bulks list with the proposed indications of cerebral ischemia, migraine, and trigeminal neuralgia. Sold for research and commercial use in compliance with the buyer's local regulations.
Frequently asked questions
Why is Semax almost always administered intranasally in research?▾
Semax is a hydrophilic heptapeptide that does not meaningfully cross the blood-brain barrier when administered systemically, systemic dosing produces detectable plasma levels but very little brain exposure. Intranasal administration bypasses the BBB through direct olfactory-nerve and trigeminal-nerve transport into the CNS, plus some absorption through the respiratory epithelium into systemic circulation. The published Russian and Western research literature is dominated by intranasal protocols for this reason. Buyers preparing intranasal formulations should use isotonic vehicles and avoid quaternary-ammonium preservatives.
What's the difference between Semax and N-Acetyl-Semax?▾
N-Acetyl-Semax is a variant with an N-terminal acetylation that confers additional resistance to aminopeptidase cleavage. The acetylation extends functional half-life beyond unmodified Semax and is sometimes preferred for research applications where extended duration of action matters. Lyochem's standard Semax SKU is the unmodified form; N-Acetyl-Semax and other Semax-family analogues are available on request through the OEM service.
Is Semax suitable for compounding pharmacy use in the US?▾
Semax is currently under FDA Pharmacy Compounding Advisory Committee (PCAC) review for inclusion on the 503A bulks list (July 2026 meeting agenda), with proposed indications of cerebral ischemia, migraine, and trigeminal neuralgia. Until the FDA acts on the PCAC recommendation, US compounding pharmacy use is constrained by the current regulatory posture. Buyers in the US should verify the current status at the time of dispense; buyers in jurisdictions with different regulatory frameworks (including Russia where Semax is an approved medication) should reference their local registry.