Selank vs Semax
Selank and Semax are short synthetic peptides developed at the Institute of Molecular Genetics in Moscow and studied extensively in Russian neuropharmacology research. Selank is investigated primarily for anxiolytic properties, Semax for nootropic and neuroprotective effects.
Side-by-Side Comparison
| Property | Selank | Semax |
|---|---|---|
| Category | Synthetic tuftsin analog (heptapeptide) | Synthetic ACTH(4-7) analog with Pro-Gly-Pro extension (heptapeptide) |
| Mechanism of Action | Modulates GABAergic transmission, inhibits enkephalin-degrading enzymes, influences expression of inflammatory and neurotransmitter-related genes | Upregulates BDNF and its TrkB receptor, modulates dopaminergic and serotonergic systems without ACTH-like hormonal activity |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro (tuftsin + PGP stabilizer) | Met-Glu-His-Phe-Pro-Gly-Pro (ACTH 4-7 + PGP stabilizer) |
| Molecular Weight | ~751 Da | ~813 Da |
| Primary Research Focus | Anxiety models, stress response, immune modulation | Cognitive function, attention, neuroprotection in ischemia models |
| Half-Life | Minutes in circulation (rapid enzymatic degradation; PGP motif slows breakdown) | Minutes in circulation (PGP motif slows breakdown; effects outlast plasma presence) |
| Key Research Citations | Zozulya et al. (2008), Bull Exp Biol Med; Kolomin et al. (2013), Bull Exp Biol Med | Dolotov et al. (2006), J Neurochem; Ashmarin et al. (1997), Zh Vyssh Nerv Deiat |
Key Differences
- Selank derives from tuftsin, an immunomodulatory tetrapeptide; Semax derives from the ACTH(4-7) fragment of adrenocorticotropic hormone, engineered to remove hormonal activity.
- Selank research centers on anxiolytic endpoints and GABA system modulation; Semax research centers on cognition, attention, and BDNF-mediated neuroprotection.
- Semax has been studied in Russian clinical settings for ischemic stroke and cognitive impairment; Selank’s clinical research history is concentrated in generalized anxiety models.
- Both share the C-terminal Pro-Gly-Pro stabilizing motif and very short plasma half-lives, with biological effects that persist well beyond circulating levels.
Research Summary
Selank and Semax are structurally related heptapeptides that share a Pro-Gly-Pro stabilizing tail but diverge in origin and research focus. Selank, a tuftsin analog, is studied for anxiolytic and immunomodulatory effects through GABAergic and enkephalinergic mechanisms. Semax, an ACTH-fragment analog stripped of hormonal activity, is studied for nootropic and neuroprotective effects driven largely by BDNF upregulation. Both exemplify the regulatory-peptide approach of producing lasting neurochemical changes from transient plasma exposure.
What is the difference between Selank and Semax?
Selank is a tuftsin-derived heptapeptide studied for anxiolytic effects via GABAergic modulation and enkephalinase inhibition. Semax is an ACTH(4-7)-derived heptapeptide studied for nootropic and neuroprotective effects via BDNF upregulation. Both were developed in Russia, share a stabilizing Pro-Gly-Pro tail, and have very short plasma half-lives with effects that outlast circulating levels.
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Disclaimer: All compounds referenced on this page are sold for research and laboratory use only. The comparisons presented are based on published scientific literature and are intended for educational and informational purposes. This content does not constitute medical advice. Researchers should consult primary literature and applicable regulations before designing study protocols.