ACTH-derived heptapeptide developed in Russia. Studied for nootropic effects, BDNF upregulation, stroke recovery, and neurological protection. Approved in Russia and Ukraine as a drug.
Semax is a synthetic peptide developed in Russia based on a fragment of ACTH (adrenocorticotropic hormone). Despite being derived from a stress hormone fragment, Semax does not produce significant cortisol stimulation. It has been studied extensively in Russia for neuroprotection, cognitive enhancement, and stroke recovery, and is approved for clinical use in Russia and Ukraine.
Neuroprotection and Stroke Research
Semax is approved in Russia for ischemic stroke treatment and brain injury recovery. Clinical studies report reductions in neurological deficit and accelerated functional recovery compared to standard care. Animal research shows protection against ischemic brain damage through BDNF upregulation and anti-inflammatory effects.
Cognitive Enhancement Research
Russian clinical studies have examined Semax for cognitive improvements in conditions including ADHD, age-related cognitive decline, and post-surgical cognitive decline — the temporary memory and concentration difficulties some people experience after general anesthesia or major surgery. Studies report improvements in attention, memory, and executive function measures.
BDNF and Neurotrophin Research
A key mechanistic finding is that Semax significantly increases BDNF (brain-derived neurotrophic factor) levels — a protein critical for neuron survival, synaptic plasticity, and learning. This BDNF-enhancing effect is a major focus of current research interest.
Approved in Russia for stroke and brain injury, with clinical trial evidence supporting this use.
Increases BDNF levels in the brain — one of the most robustly reproduced mechanistic findings.
Russian clinical data show cognitive improvements across several conditions.
Animal studies confirm neuroprotective effects in ischemia models.
Not evaluated in large Western randomized controlled trials.
Semax's evidence base is predominantly from Russian research programs and has not been replicated in large independent Western trials. It is not FDA-approved. The nasal delivery used in most studies has variable and individual-specific bioavailability. Long-term safety with regular use is not established. The cognitive enhancement findings in clinical populations may not generalize to cognitively healthy individuals.
Semax is derived from a segment of the stress hormone ACTH but was modified to remove the cortisol-stimulating effects. What remains is a peptide that interacts with melanocortin receptors and, more importantly, strongly upregulates the production of BDNF in the brain. BDNF is like fertilizer for neurons — it promotes the growth of new connections, protects existing neurons from dying under stress, and supports the plasticity that underlies learning and memory. Low BDNF is associated with depression, cognitive decline, and poor recovery from brain injury. By boosting BDNF, Semax may support the brain's natural repair and maintenance systems.
Semax has been used clinically in Russia for decades with a generally favorable safety profile in published literature. No significant adverse effects have been widely reported in clinical studies. It does not produce meaningful cortisol stimulation despite being derived from an ACTH fragment — the structural modifications removed the cortisol-triggering portion. It is not FDA-approved. Nasal delivery carries the usual considerations about mucosal health and dose consistency.
Moderate Evidence
This compound has been studied in Phase 1 or Phase 2 human trials. Evidence is encouraging but more large-scale trials are needed.
Published Research Ranges
100–600mcg/day intranasal in clinical studies
Research Context Only: These are ranges reported in published scientific studies for educational reference. They are not dosing recommendations. This is not medical advice. Always consult a qualified healthcare professional.
Sources listed here are from the platform research library. All links open the original publication. No citations are generated by AI.
Semax — A Synthetic ACTH(4-10) Analogue: Neuroprotective and Cognitive Effects
CNS Drug Reviews • 2002
• DOI: 10.1111/j.1527-3458.2002.tb00200.x
Insight into Glyproline Peptides' Activity through the Modulation of the Inflammatory and Neurosignaling Genetic Response Following Cerebral Ischemia-Reperfusion
Antistress Action of Melanocortin Derivatives Associated with Correction of Gene Expression Patterns in the Hippocampus of Male Rats Following Acute Stress
ACTH(6-9)PGP Peptide Protects SH-SY5Y Cells from H2O2, tert-Butyl Hydroperoxide, and Cyanide Cytotoxicity via Stimulation of Proliferation and Induction of Prosurvival-Related Genes
Novel Insights into the Protective Properties of ACTH(4-7)PGP (Semax) Peptide at the Transcriptome Level Following Cerebral Ischaemia-Reperfusion in Rats
Schisandra chinensis and Rhodiola rosea exert an anti-stress effect on the HPA axis and reduce hypothalamic c-Fos expression in rats subjected to repeated stress
Research Education Only: This profile is for educational purposes only. All information is sourced from published scientific literature. This is not medical advice. Not for human consumption. Consult qualified medical professionals for any health decisions.
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