Semax: The ACTH 4-10 Cognitive Heptapeptide

Semax is the cognitive side of the best-known Russian research-peptide pair. Where Selank grew from an immune peptide’s sequence, Semax grew from a hormone fragment — and it was deliberately modified to last longer than the natural molecule it came from.

The molecule

Semax is the heptapeptide Met-Glu-His-Phe-Pro-Gly-Pro (C₃₇H₅₁N₉O₁₀S, ≈ 814 g/mol), an analog of the ACTH 4-10 fragment. The natural fragment is short-lived; Semax was engineered for stability, which is what turned a transient hormone fragment into a research compound with a workable half-life.

What the research looks at

Semax appears in three main threads:

• Cognitive-enhancement and nootropic research — learning and memory behavioral models are the core of its literature
• BDNF signaling — brain-derived neurotrophic factor pathways are a recurring mechanistic focus, connecting peptide treatment to synaptic plasticity
• Neuroprotection — studied alongside its cognitive effects in models of CNS stress and damage

It is frequently paired with Selank in cognitive-panel research — the two share a design lineage but target different ends of the behavioral spectrum.

Handling notes

Lyophilized, reconstitute with bacteriostatic water; the reconstitution calculator does the liquid math. Store at −20°C lyophilized.

See Semax for CAS, purity and full specifications.

For laboratory research use only. Not medical advice.