An ACTH-derived nootropic peptide that dramatically upregulates BDNF and enhances cognitive performance.
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) derived from the 4–7 fragment of ACTH (adrenocorticotropic hormone), developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It has been approved in Russia for the treatment of ischemic stroke, traumatic brain injury (TBI), and cognitive disorders, and is widely used as a nootropic. Semax’s most notable property is its ability to dramatically upregulate BDNF (brain-derived neurotrophic factor) — by up to 400% in animal models — making it one of the most potent BDNF-enhancing agents known. BDNF is critical for neuroplasticity, memory consolidation, and neuroprotection. Semax also has neuroprotective effects in ischemia models, reduces oxidative stress in neural tissue, and has demonstrated anti-depressant and anxiolytic properties in addition to its cognitive-enhancing effects.
* Benefits based on preclinical/animal research unless otherwise noted.
Semax’s primary mechanism involves activation of the BDNF-TrkB signaling pathway. It upregulates BDNF gene expression in the hippocampus and prefrontal cortex through mechanisms involving CREB (cAMP response element-binding protein) activation and histone acetylation at the BDNF promoter. Elevated BDNF then activates TrkB receptors, triggering PI3K/Akt (cell survival), MAPK/ERK (synaptic plasticity), and PLCγ (calcium signaling) pathways that support long-term potentiation (LTP) and memory formation. Semax also activates dopaminergic and serotonergic systems in the prefrontal cortex and hippocampus, contributing to improved focus, mood, and working memory. Its neuroprotective effects in ischemia involve reduction of oxidative stress (upregulation of SOD and catalase), inhibition of apoptotic pathways, and promotion of angiogenesis in ischemic tissue. Intranasal administration provides rapid CNS delivery through olfactory nerve pathways, with peak CNS concentrations within 30 minutes.
Protocol Notes: Intranasal administration is preferred for CNS delivery. Morning dosing is recommended to avoid sleep disruption.
Available as nasal spray. Injectable: add 1 mL bacteriostatic water per mg.
When sourcing Semax for research purposes, the following quality benchmarks should be verified before use.
Refrigerate. Nasal spray: use within 30 days.
The statements made within this website have not been evaluated by the US Food and Drug Administration. The products and information provided are not intended to diagnose, treat, cure, or prevent any disease. This website is intended for educational and research purposes only. Many peptides described on this site are not approved by the FDA for human therapeutic use and are classified as research chemicals. Nothing on this site constitutes medical advice.
Moderate Evidence — Multiple animal studies and/or early human trials. Reasonable confidence in mechanism, but human data is limited.
Peptides commonly used alongside Semax for synergistic effects.
Dopaminergic Nootropic + Mitochondrial Support
A powerful dopaminergic nootropic combined with a mitochondria-targeting electron carrier for enhanced cognitive function.
Learn More: 9-ME-BC + Methylene Blue (Capsule)Angiotensin IV Analog / Nootropic
An angiotensin IV analog reported to be 10 million times more potent than BDNF at promoting synaptogenesis.
Learn More: Dihexa (Capsule)