Pure North Peptides Journal · Compendium
Semax: ACTH-derived cognitive research peptide overview
Published 2024-06-30 · Pure North Peptides Editorial · Canada
Short answer. Semax is a 7-residue synthetic peptide derived from ACTH 4–10 (Met-Glu-His-Phe-Pro-Gly-Pro) with a C-terminal PGP extension that resists proteolysis. Investigated in published research as a CNS-active short peptide. Semax is not currently stocked by Pure North Peptides; see the current catalog for available reference standards.
Origin: ACTH 4–10
Adrenocorticotropic hormone residues 4–10 (Met-Glu-His-Phe-Arg-Trp-Gly) is the minimal melanocortin-receptor active fragment in published literature. Semax replaces the natural sequence with Met-Glu-His-Phe and appends Pro-Gly-Pro for stability — the resulting heptapeptide retains the N-terminal ACTH-derived core while the C-terminal cap blocks proteolysis.
Sequence and mass
Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP). Mass 813.94 Da. The methionine residue is air-sensitive; reference-grade material should be sealed under nitrogen and stored cold.
Quality criteria
- RP-HPLC purity ≥ 99%.
- ESI-MS at 813.94 Da ± 0.3 Da.
- Methionine sulfoxide content < 2% (oxidation marker).
- Net peptide content ≥ 80% by AAA.
Storage caveats
Methionine oxidation is the dominant degradation pathway. Lyophilized vials should be sealed under nitrogen and stored cold; opening protocols should minimize air exposure. After reconstitution, 2–8 °C for 14 days maximum, or −80 °C aliquots in single freeze-thaw protocol.
Mechanism hypotheses
Published research investigates Semax's effects on BDNF expression, neurotrophin signaling, and monoamine turnover in CNS-relevant cell lines. As with most short peptides in this class, no single canonical mechanism is established; mechanistic claims should be tied to the specific assay being run.
Semax is not currently stocked by Pure North Peptides. For available HPLC-verified reference standards, see the current catalog →, or review the guide to reading a peptide COA before evaluating any supplier's material.
Frequently asked questions
What is Semax derived from?
It is based on ACTH residues 4–10 with a Pro-Gly-Pro C-terminal extension for protease resistance.
Is Semax related to Selank?
Both are short synthetic peptides studied in CNS research with PGP extensions, but they derive from different parent proteins (ACTH vs tuftsin).
Why is methionine oxidation a concern?
The N-terminal methionine in Semax oxidizes to methionine sulfoxide on air exposure, shifting receptor pharmacology. Reference-grade material should show < 2% Met-O.
What is Semax's molecular weight?
813.94 Da. ESI-MS confirmation should fall within 0.3 Da on a competent COA.
Where to buy Semax reference standard in Canada?
Semax is not currently stocked by Pure North Peptides. See the current catalog for available HPLC-verified reference standards.
Disclaimer: All Pure North Peptides products are supplied for laboratory research use only. They are not approved by Health Canada as drugs. See our research-use declaration for full terms.