Semax: A Synthetic ACTH Analog — Research Overview
Semax: A Synthetic ACTH Analog — Research Overview
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences by modifying the ACTH(4-7) fragment (Met-Glu-His-Phe) — the portion of adrenocorticotropic hormone believed to carry its nootropic activity — with a C-terminal Pro-Gly-Pro tripeptide that confers resistance to enzymatic degradation. Notably, Semax was designed to retain the neurotrophic properties of the ACTH fragment while eliminating the steroidogenic (adrenal cortex-stimulating) activity of full-length ACTH (Ashmarin et al., Doklady Biological Sciences, 1995).
Mechanism of Action
Semax operates through several interconnected neurotrophic and neuromodulatory pathways:
Neurotrophic factor upregulation: The most consistently reported mechanism in preclinical studies is Semax's ability to upregulate the expression of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the hippocampus, frontal cortex, and basal forebrain. BDNF and NGF are critical neurotrophins that support neuronal survival, synaptic plasticity, and memory formation (Dolotov et al., Neuroscience Letters, 2006; PMID: 16814445).
Melanocortin receptor interaction: As a derivative of the ACTH sequence, Semax interacts with melanocortin receptors (MC3R and MC4R), which are expressed throughout the central nervous system and implicated in learning, memory, motivation, and neuroprotection. Semax's binding profile at melanocortin receptors is thought to underlie some of its observed cognitive effects.
Monoamine modulation: In rodent brain tissue, Semax administration has been associated with alterations in dopaminergic and serotonergic metabolism in the striatum and hippocampus, including changes in the ratios of neurotransmitters to their metabolites (Eremin et al., Doklady Biological Sciences, 2005; PMID: 16250582).
Neuroprotective mechanisms: In models of oxidative stress, Semax has been observed to modulate the expression of antioxidant enzymes and inflammatory cytokines, suggesting possible neuroprotective mechanisms beyond direct neurotrophic support.
Published Research
BDNF and NGF expression: Dolotov et al. demonstrated that Semax administration in rodents was associated with significant upregulation of BDNF mRNA and protein levels in the hippocampus and basal forebrain, with effects observed within 30 minutes and persisting for several hours (Dolotov et al., Neuroscience Letters, 2006; PMID: 16814445).
Cognitive function: In passive avoidance, Morris water maze, and novel object recognition paradigms, Semax-treated rodents showed improved acquisition, consolidation, and retrieval of learned behaviors compared to saline-treated controls. These cognitive improvements correlated temporally with changes in neurotrophic factor expression.
Ischemic models: In rodent models of cerebral ischemia, Semax administered during the acute phase was associated with reduced infarct volume and improved behavioral outcomes. Gene expression profiling revealed that Semax modulated the expression of immune and inflammatory genes in the ischemic penumbra (Agapova et al., Molecular Biology, 2007).
Gene expression profiling: Transcriptomic studies using microarray analysis identified that Semax modulates the expression of genes involved in immune response, vascular regulation, and neuronal signaling in brain tissue, providing a molecular framework for its observed multifactorial effects.
Purity and Quality Considerations
Semax contains methionine at the N-terminus, which is susceptible to oxidation during storage and handling. Researchers should verify purity by HPLC and mass spectrometry, paying particular attention to the presence of methionine sulfoxide as an oxidation indicator. Proper storage under inert atmosphere and at recommended temperatures is important. Learn more about peptide purity testing and quality verification standards.
Available for Research
CALM Peptides offers research-grade Semax with third-party purity verification. Certificates of Analysis are available upon request. Browse all sleep & neurological peptides or explore our full catalog.
Frequently Asked Questions
What is Semax?
Semax is a synthetic heptapeptide derived from the ACTH(4-10) fragment with a stabilizing Pro-Gly-Pro C-terminal extension. It was developed at the Russian Academy of Sciences and has been studied in preclinical models for neurotrophic, nootropic, and neuroprotective properties.
Does Semax stimulate cortisol production like ACTH?
No. Semax was specifically engineered to retain the neurotrophic properties of the ACTH(4-7) fragment while eliminating the steroidogenic activity of full-length ACTH. It does not stimulate the adrenal cortex in preclinical models.
What neurotrophic factors has Semax been observed to influence?
In preclinical studies, Semax has been most consistently associated with upregulation of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in hippocampal and cortical brain regions.
How are Semax and Selank related?
Both were developed at the same Russian research institute as synthetic neuropeptides with stabilizing Pro-Gly-Pro tails, but they derive from different parent molecules. Semax derives from ACTH(4-10) and primarily targets neurotrophic pathways, while Selank derives from tuftsin and primarily targets GABAergic and immunomodulatory pathways.
The information presented in this article is for educational and informational purposes only and is not intended as medical advice. Semax is sold as a research chemical for laboratory use only. It is not intended for human consumption, and should not be used to diagnose, treat, cure, or prevent any disease. All references to published research are provided for informational context. Consult qualified professionals for guidance related to any health condition.
For research use only. Not for human consumption.
Related Reading: What Are Peptides? · Sleep & Neurological Peptides · Selank Research Overview · DSIP Research Overview · Quality & Purity Standards · Peptide Purity Testing
The information presented in this article is for educational and informational purposes only and is not intended as medical advice. All products referenced are sold as research chemicals for laboratory use only. They are not intended for human consumption and should not be used to diagnose, treat, cure, or prevent any disease. All references to published research are provided for informational context. Consult qualified professionals for guidance related to any health condition.