Semax is a synthetic heptapeptide derived from the N-terminal sequence of adrenocorticotropic hormone (ACTH). Developed in Russia in the 1980s, it has been the subject of substantial neurological research, particularly in the context of neuroprotection and cognitive function. This profile covers its mechanism, key research findings, and what researchers need to know when sourcing it.
What is Semax?
Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic analogue of the ACTH(4-7) fragment. Unlike ACTH itself, it has no adrenocortical activity — the modifications that create Semax remove the hormonal activity of the parent peptide while preserving its neurological interactions. This makes it useful for studying the neurological effects of ACTH-related sequences without confounding hormonal effects.
Mechanism of action
Semax has been studied for several neurological mechanisms. Its most researched effect is upregulation of brain-derived neurotrophic factor (BDNF) and its receptor TrkB in the hippocampus and frontal cortex. BDNF is a key regulator of neuronal survival, synaptic plasticity and long-term potentiation — making compounds that modulate it of significant interest in neuroscience research. Semax has also been studied for its interactions with the serotonergic and dopaminergic systems, and for neuroprotective effects in ischaemic models.
Research areas
The Semax research literature spans several areas. Neuroprotection studies have examined its effects in stroke and ischaemia models, where it has shown consistent protective effects in rodent research. Cognitive research has investigated its influence on memory consolidation and learning in animal models. Mood and anxiety research has studied its interactions with serotonin pathways. Its BDNF-upregulating properties have also made it relevant to research into neurodegenerative disease models.
Semax and Selank in combined protocols
Semax is frequently studied alongside Selank in neurological research. While Semax is primarily studied for its stimulatory and neurotrophic effects, Selank is studied for anxiolytic and GABAergic interactions — the two compounds have complementary rather than overlapping mechanisms, making combined protocols useful for researchers studying multiple aspects of neurological function.
Purity requirements
Neurological research is sensitive to peptide impurities, which can interact with the same receptors as the target compound and introduce noise into assays. Every Semax batch Pepreta supplies is characterised by RP-HPLC to ≥99% purity, ESI-MS identity confirmation and LAL endotoxin screening, with a batch Certificate of Analysis available.
Sourcing Semax for research
Pepreta supplies Semax as HPLC-verified lyophilised powder in 5mg and 10mg vials, dispatched from Sydney and Melbourne. For reconstitution guidance see our reconstitution guide. Supplied for laboratory and research use only — not for human or animal consumption.