Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) developed in Russia as an analog of the ACTH(4-10) fragment, engineered with a C-terminal Pro-Gly-Pro extension that slows enzymatic degradation. It has been studied for decades in Russian preclinical and clinical research programs and remains widely cited in the neuropeptide literature.
Research background
The preclinical work around Semax concentrates on neurotrophin signaling — most prominently BDNF expression in rodent models — along with studies of attention, ischemia models, and stress responses in laboratory animals. Unlike its parent ACTH fragment, Semax shows minimal corticotropic (adrenal-stimulating) activity in the published models, which is precisely why the analog was engineered.
Structure and stability
At seven residues, Semax is a short, robust peptide. The Pro-Gly-Pro tail is the defining stability feature: it protects the active core from aminopeptidase and carboxypeptidase cleavage in experimental systems. The N-terminal methionine is the molecule’s oxidation-sensitive point — a degraded lot shows a methionine-sulfoxide satellite peak on HPLC, which is one reason a recent, lot-specific certificate matters more than a generic spec sheet.
Reading a Semax certificate of analysis
A proper certificate reports chromatographic purity (percent of total peak area), identity confirmation against a reference standard, and net peptide content per vial. Heartland Bio Labs publishes independent lab certificates for tested lots in the COA portal; search the product name to read the transcribed results with the original laboratory PDF attached.
Handling notes
Lyophilized Semax stores cold, dry, and dark. Because of the oxidizable methionine, avoiding repeated exposure of reconstituted solution to air is standard laboratory practice; solutions are prepared fresh.
Frequently asked research questions
How does Semax relate to Selank?
Selank is a different Russian-developed heptapeptide (a tuftsin analog) with its own literature centered on anxiety-related models; the two are frequently studied together but are structurally unrelated beyond both carrying the stabilizing Pro-Gly-Pro tail.
What strengths are typical?
Research vials are commonly offered at 5 mg and 10 mg of lyophilized peptide.
All compounds discussed are for laboratory research use only and are not for human consumption. Nothing here is medical advice or a statement of clinical effect.
Product page: Semax.