Selank vs Semax: Nootropic Peptide Comparison | Regena

Selank is a synthetic heptapeptide derived from the immunomodulatory tetrapeptide tuftsin, with additional Pro-Gly-Pro C-terminal stabilisation. Its proposed research mechanism centres on GABAergic-axis modulation, BDNF-axis effects and downstream anxiolytic-profile signalling in preclinical models.

Semax is a synthetic heptapeptide derived from the 4–10 fragment of adrenocorticotropic hormone (ACTH), with Pro-Gly-Pro C-terminal stabilisation. Its proposed research mechanism centres on BDNF- and NGF-axis modulation and downstream cognitive- and neuroprotective-axis signalling in preclinical models.

Selank does not act through a single canonical receptor. Published research suggests indirect GABAergic-axis modulation and BDNF-axis effects, with a research profile centred on anxiolytic and immunomodulatory endpoints.

Semax likewise does not act through a single canonical receptor. Published research emphasises BDNF- and NGF-axis modulation, with a research profile centred on cognitive-axis and neuroprotective endpoints.

Both compounds are short heptapeptides with Pro-Gly-Pro stabilisation, and both are researched via intranasal administration as the primary route — a distinctive feature versus most other research peptides. Research cadences are typically daily.

The intranasal route is the reason both compounds are studied in CNS-axis research models — direct nose-to-brain delivery bypasses the substantial first-pass metabolism that would limit oral or subcutaneous administration of these short peptides.

Selank is used in anxiolytic-axis, immunomodulatory and GABAergic-axis research models. The tuftsin-derived structure gives it a research profile distinct from classical benzodiazepine-axis anxiolytic comparators.

Semax is used in cognitive-axis, neuroprotective and BDNF/NGF-axis research models. The ACTH-derived structure gives it a research profile distinct from classical nootropic small molecules.

Both Selank and Semax ship from Regena only after independent third-party verification — Janoshik Analytical is the default verifier, with orthogonal independent laboratories used when batch chemistry calls for confirmation by a second method. Minimum release specification is ≥99.0% HPLC main-peak purity with matching mass-spectrometry molecular weight and water content within the published specification for the compound.

Batch COAs for both compounds are published on the Regena lab reports page so a research-peptide buyer can audit the analytical detail before purchase. The /trust/how-to-read-a-coa reference walks through every field on a modern Regena COA.

Both compounds ship as lyophilised research peptides. Hold at 2–8 °C; freeze at −20 °C for long-term storage. Reconstitution for intranasal-administration research is typically with sterile saline; bacteriostatic-water reconstitution is used for subcutaneous research protocols. Both compounds are sensitive to repeat freeze-thaw cycling — aliquot before any freeze.

Aliquot before any freeze. The single most common cause of measurable potency loss in research peptides is repeat freeze-thaw cycling — both Selank and Semax benefit from single-thaw aliquot workflows. Vortex gently, never shake aggressively, and keep reconstituted vials away from direct light. The /research/compound-storage-guide reference covers the per-compound stability windows in detail.

Researchers choose Selank when the protocol targets anxiolytic-axis or immunomodulatory endpoints, particularly where GABAergic-axis modulation is central to the experimental design. Researchers choose Semax when the protocol targets cognitive-axis or neuroprotective endpoints, particularly where BDNF- and NGF-axis signalling is the experimental focus. Matched panels sometimes include both compounds where a complete Russian-origin nootropic-peptide comparator is required.

For multi-compound comparator studies, the Regena consultations team will reserve matched-batch inventory of both Selank and Semax against a project timeline so the experimental panel is sourced under a single analytical specification window.

Both Selank and Semax are supplied strictly for in-vitro and preclinical research use. They are not medicines, are not approved for human consumption in Spain, the United Kingdom, the European Union or the United States, and are not dispensed against a prescription. The research-use declaration ships with every package alongside the independent third-party COA.

Comparison pages on the Regena site exist for laboratory-research reference. Nothing on this page constitutes a recommendation for human use of either compound.