Semax: an ACTH(4-10) analogue research peptide

Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) derived from the ACTH(4-10) fragment and developed in the CIS as a neuroactive research compound. The notes below summarise its laboratory research context for qualified investigators, strictly for in-vitro and preclinical use.

Structure and Origin

Semax is a synthetic heptapeptide with the amino-acid sequence Met-Glu-His-Phe-Pro-Gly-Pro and the molecular formula C37H51N9O10S (CAS 80714-61-0). It is structurally derived from the 4-10 fragment of adrenocorticotropic hormone (ACTH), to which a Pro-Gly-Pro tripeptide tail has been appended at the C-terminus. This terminal extension is reported in the literature to markedly increase resistance to enzymatic degradation relative to the parent fragment, lengthening the molecule's stability in experimental systems. Semax was developed in the 1980s at the Institute of Molecular Genetics of the Russian Academy of Sciences by a group led by Nikolai Myasoedov and Isaak Ashmarin, which is why it is often described as a CIS-native research peptide. Because the ACTH(4-10) core lies outside the steroidogenic portion of the parent hormone, Semax is studied as a non-corticotropic melanocortin-related fragment in laboratory work rather than as a hormone analogue. In research lots the compound is supplied as a white lyophilised solid, and its short, fully synthetic sequence makes it convenient to characterise by mass spectrometry and to handle in standard peptide-chemistry workflows.

Neurotrophic Signalling in Research Models

A central theme in the Semax literature is its reported influence on neurotrophin expression. In cultured cells and rodent brain tissue, studies have described elevated transcription and protein levels of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), together with changes in their cognate receptor (TrkA/TrkB) signalling pathways. Transcriptomic analyses of hippocampal tissue in animal models have reported shifts in the expression of genes linked to neurotrophic support, vascular factors, and immune-modulatory mediators following Semax exposure. These observations position the peptide as a research tool for probing how a short ACTH-derived sequence may engage neurotrophic cascades. All such findings are descriptive of cellular and animal-model systems used to investigate molecular mechanisms; they are reported here only as literature context for laboratory study and carry no implication for use outside controlled research settings. Researchers frequently pair such expression read-outs with electrophysiological or behavioural assays in animal models to ask whether neurotrophic changes correlate with measurable shifts in synaptic plasticity markers.

Neuroprotection and Oxidative-Stress Pathways

Semax has been examined in preclinical models of cerebral ischaemia and oxidative challenge. In rodent global-ischaemia paradigms, published work has reported reductions in cortical nitric-oxide production and in markers of ischaemic neuronal injury when the peptide is present in the experimental system. Proposed mechanisms discussed in the literature include modulation of oxidative-stress responses, attenuation of inflammatory signalling, and support of neuronal survival pathways, potentially downstream of the neurotrophic changes noted above. Researchers also study Semax in the context of the melanocortin system and BDNF-linked signalling to dissect which receptor populations and second-messenger routes mediate these effects. These are mechanistic, hypothesis-generating studies conducted in cell cultures and laboratory animals. The summary is provided solely to frame the molecule for in-vitro and preclinical investigation and does not describe or endorse any application involving humans. Comparative work with the parent ACTH(4-10) fragment and with truncated analogues is also used to map which residues contribute to the reported activity in these experimental systems.

Handling and Research Use

Semax supplied by Peptiko is a lyophilised research peptide reagent intended exclusively for in-vitro and laboratory research by qualified researchers and institutions. As a hygroscopic peptide it is typically stored desiccated and protected from light, with reconstituted working solutions kept cold and used promptly to limit degradation; investigators should follow their own validated protocols and the accompanying Certificate of Analysis. Identity and purity for research lots are characterised by HPLC-MS, and a CAS reference (80714-61-0) supports traceability. As with all reagents in the catalogue, Semax is offered for laboratory research only and is not a drug, food, cosmetic, or medical product; no human or animal administration is described, supported, or intended. Peptiko does not supply GLP-1 receptor agonists such as Semaglutide, Tirzepatide, or Retatrutide. Questions on documentation, purity data, or compound characterisation can be directed to Peptiko for the relevant research records, and each research lot is intended to be matched to its batch-specific analytical report for full traceability in the laboratory.

Related guides

Khavinson peptide bioregulators What are peptides? HPLC purity testing explained