Selank vs Semax: Comparing Two Russian Neuropeptide Research Compounds

For in-vitro and laboratory research only. Neither compound is approved for therapeutic use outside specific national contexts; published literature summarized below is preclinical or limited-clinical.

Selank and Semax are two synthetic heptapeptides developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. Both have been studied for decades in Russian research literature, with a smaller body of independent replication outside of that. They are often grouped together but address different biological systems. Available as Selank 5mg and Semax 5mg.

What each molecule is

Selank

Selank is a synthetic analog of the immunomodulatory tetrapeptide tuftsin (Thr-Lys-Pro-Arg), extended with a Pro-Gly-Pro stabilizing C-terminus — total length 7 amino acids. Research literature emphasizes anxiolytic and immunomodulatory mechanisms in rodent models.

Semax

Semax is a synthetic analog of ACTH(4-10) (Met-Glu-His-Phe-Pro-Gly-Pro), preserving the central neuropeptide-active region of ACTH but removing the corticotropin-stimulating activity. Research literature emphasizes cognitive, neuroprotective, and BDNF-related mechanisms.

Side-by-side comparison

Attribute	Selank	Semax
Parent peptide	Tuftsin	ACTH(4-10)
Length	7 amino acids	7 amino acids
Primary mechanism	GABA/BDNF modulation, immunomodulation	BDNF/NGF upregulation, neuroprotection
Primary research context	Anxiolytic and stress models	Cognitive and ischemic models

Mechanisms reported in published literature

Selank

• Modulation of GABAergic signaling in rodent anxiety models.
• Changes in expression of cytokines including IL-6 and IFN-γ in cell-culture immunomodulation assays.
• BDNF expression changes in rat hippocampal tissue.

Semax

• Upregulation of BDNF and NGF in rat-brain studies.
• Neuroprotective effects in middle-cerebral-artery-occlusion (MCAO) rodent ischemic models.
• Modulation of dopaminergic and serotonergic systems in behavioral models.

Common research-model applications

• Rodent anxiety paradigms (elevated plus maze, open field) for Selank.
• Rodent cognitive paradigms (Morris water maze, novel object recognition) for Semax.
• Both have been studied in models of stress-induced behavioral changes.

Handling and storage

Both peptides ship lyophilized. Standard storage applies — see our peptide storage guide. Both are typically reconstituted in bacteriostatic or sterile water; some research protocols use intranasal-formulation buffers for in-vivo work.

Related peptides

For other neuropeptide research compounds in the catalog, see DSIP 5mg (delta sleep-inducing peptide) and Pinealon 10mg.

What to verify on the COA

• Full sequence for Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) and Semax (Met-Glu-His-Phe-Pro-Gly-Pro). Easy to mix up — both are heptapeptides starting with non-canonical residues.
• Purity ≥98% by HPLC.
• Mass spec match.

See how to read a peptide COA.

Reminder: All content above is summarized from preclinical literature for laboratory and educational use. Products are not intended for human consumption.