Semax Research Overview (also known as ACTH 4-7 PGP, Semax nootropic, Met-Glu-His-Phe-Pro-Gly-Pro)

For broader research context on nootropic compounds, including comparative stacks, cycling considerations, and interaction notes, see the Complete Nootropic Cheat Sheet.

For the FDA advisory panel discussion of Semax, see FDA Advisory Panel Day 2 Results: Semax and Epitalon Recommended, Emideltide Rejected.

What Is Semax?

Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) derived from the N-terminal ACTH 4-10 fragment, stabilized with an added Pro-Gly-Pro sequence that confers CNS stability. Developed at the Institute of Molecular Genetics of the Russian Academy of Sciences and approved for clinical use in Russia and Ukraine, Semax is one of the most extensively studied and widely used nootropic/neuroprotective peptides from the Russian pharmacological tradition.

BDNF and Neurotrophic Signaling

Semax's most significant mechanistic property is its capacity to dramatically increase BDNF expression in the hippocampus and cortex — with studies showing increases of 7-fold or more in BDNF mRNA. This BDNF elevation is the central mechanism through which Semax exerts its neuroprotective and cognitive-enhancing effects, governing synaptic plasticity, neuron survival, neurogenesis, and cognitive function.

Stroke, Cognitive Enhancement, and ADHD Research

Semax's most established clinical application is neuroprotection and recovery enhancement in ischemic stroke — standard-of-care for ischemic stroke in Russia. Beyond neuroprotection, it has been studied for cognitive enhancement in healthy subjects (with documented improvements in attention, memory, and processing speed) and in ADHD, where its dopaminergic and noradrenergic modulating effects may address attention regulation deficits through a mechanistic pathway distinct from methylphenidate or amphetamine.

Quick Reference

Research Indications

Research Protocols

As reported in cited literature and research-community logs (see Research Citations below), not a personal dosing recommendation.

Peptide Interactions

Reported Research Time Points

Safety Notes

Included for harm-reduction awareness only, in the event this compound is encountered outside its labeled research use. Inclusion here does not imply RUO Codes endorses, recommends, or instructs human use.

Quality Indicators

Research Citations

• Stroke Recovery Clinical Trial (2018)
  Human | 110 patients | Semax + conventional therapy | Ischemic stroke recovery
• fMRI Default Mode Network Study (2018)
  Human | 24 participants | Single dose intranasal | Brain imaging analysis
• Neuroprotective Effects in Brain Ischemia (2014)
  Animal | Rat focal ischemia model | Gene expression analysis | 3-24 hours post-treatment
• Cognitive Enhancement in Fatigued Workers (1996)
  Human | 250-1000μg intranasal | Single dose | 24-hour observation
• Functional Connectomic Approach to Studying Selank and Semax Effects
  Panikratova YR, Lebedeva IS, Sokolov OY, 2020, Dokl Biol Sci
• The Potential of the Peptide Drug Semax and Its Derivative for Correcting Pathological Impairments in the Animal Model of Alzheimer's Disease
  Radchenko AI, Kuzubova EV, Apostol AA, 2025, Acta Naturae
• The peptide semax affects the expression of genes related to the immune and vascular systems in rat brain focal ischemia: genome-wide transcriptional analysis
  Medvedeva EV, Dmitrieva VG, Povarova OV, 2014, BMC Genomics
• Brain Protein Expression Profile Confirms the Protective Effect of the ACTH((4-7))PGP Peptide (Semax) in a Rat Model of Cerebral Ischemia-Reperfusion
  Sudarkina OY, Filippenkov IB, Stavchansky VV, 2021, Int J Mol Sci
• ACTH-like Peptides Compensate Rat Brain Gene Expression Profile Disrupted by Ischemia a Day After Experimental Stroke
  Filippenkov IB, Shpetko YY, Stavchansky VV, 2024, Biomedicines