Compound Reviews
Selank and Semax: Shared Design, Different Parent Peptides
Two Russian-developed research peptides built on the same stabilising strategy — and why that shared tail is a synthesis decision, not a shared mechanism.
July 26, 2026 · 6 min read · Novanta Research
Two different parents
Semax derives from a fragment of adrenocorticotropic hormone; Selank derives from the immunomodulatory peptide tuftsin. They come from completely unrelated biology.
What they share is a short proline-containing tail appended to the active fragment. That addition is a stabilisation strategy: it slows enzymatic degradation of the parent fragment considerably.
What the studies examine
The Semax literature focuses on effects on brain-derived neurotrophic factor expression and on monoamine systems in rodent models. The Selank literature centres on anxiolytic-type behavioural endpoints in animals and on effects on GABAergic and serotonergic markers.
Both compounds have a substantial body of Russian-language clinical work that is difficult to evaluate against Western trial standards due to differences in reporting and registration practice.
Reading the evidence carefully
The shared tail is a formulation trick, not a mechanism. Findings for one compound should never be extrapolated to the other simply because their sequences look similar at the C-terminus.
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For laboratory and research use only. Not for human or veterinary consumption. Novanta Research is not a compounding pharmacy and nothing in this article is medical advice or a claim that any compound diagnoses, treats, cures or prevents any condition.