Semax
Semax | ACTH(4-7)-PGP | Heptapeptide Semax
Mechanism of Action
Semax is a synthetic heptapeptide based on ACTH(4-7) (the fragment Met-Glu-His-Phe from adrenocorticotropic hormone) with an added Pro-Gly-Pro C-terminal extension for metabolic stability. Developed at the Institute of Molecular Genetics of the Russian Academy of Sciences alongside selank, semax is approved in Russia as a nootropic and neuroprotective medication.
Semax does not activate the melanocortin receptors associated with full-length ACTH and does not affect cortisol or adrenal function. Instead, it influences brain function through modulation of neurotrophic factor expression. Research has shown semax significantly upregulates BDNF (brain-derived neurotrophic factor) and its receptor TrkB, as well as NGF (nerve growth factor) in the hippocampus and cortex. These neurotrophins are critical for neuronal survival, synaptic plasticity, and learning.
Semax also modulates monoaminergic neurotransmission. It influences dopaminergic and serotonergic systems in the brain, which may contribute to its cognitive-enhancing and antidepressant-like effects observed in behavioral studies. In stroke research, semax has shown neuroprotective effects when administered during the acute phase of cerebral ischemia, reducing infarct volume and improving functional outcomes in animal models.
Key Research Findings
- Levitskaya et al. (2004) demonstrated semax enhances BDNF and TrkB expression in the rat hippocampus and basal forebrain.
- Dolotov et al. (2006) showed semax increases NGF and BDNF mRNA levels in the rat brain cortex and hippocampus.
- Gusev et al. (2005) reported semax improved neurological outcomes when administered during acute ischemic stroke in a Russian clinical study.
- Ashmarin et al. (2005) reviewed the nootropic and neuroprotective activity of ACTH(4-10) analogues including semax.
References
Dosage in Research
Russian clinical protocols use intranasal doses of 250-500 mcg per day (typically 3 drops of 0.1% solution per nostril). Animal neuroprotection studies use 50-150 mcg/kg. Stroke studies used 12-18 mcg/kg/day intranasally.
Storage & Handling
Store lyophilized powder at -20C. Reconstituted solution at 2-8C, use within 14-21 days. The Pro-Gly-Pro extension provides improved stability over native ACTH fragments.
Frequently Asked Questions
What is Semax?
Semax is a synthetic heptapeptide nootropic based on the ACTH(4-7) fragment, developed and approved in Russia. It enhances BDNF and NGF expression in the brain without affecting cortisol or adrenal function.
How does Semax compare to Selank?
Both are Russian-developed heptapeptides with Pro-Gly-Pro extensions. Semax is based on ACTH(4-7) and is primarily nootropic/neuroprotective, enhancing BDNF expression. Selank is based on tuftsin and is primarily anxiolytic/immunomodulatory, enhancing GABA function. They are complementary.
Does Semax affect cortisol like ACTH?
No. Semax uses only the ACTH(4-7) fragment, which does not bind melanocortin receptors responsible for adrenal stimulation. It has no effect on cortisol levels or adrenal function.
Source Semax for your research
98%+ purity, third-party tested, COA included