Semax vs Selank
Two synthetic heptapeptides from the same research lineage, compared by mechanism, molecular profile, and the reasons they are often compared.
Overview
Semax and Selank are both synthetic heptapeptides developed at the Institute of Molecular Genetics of the Russian Academy of Sciences, and both share the same C-terminal stabilising motif, Pro-Gly-Pro, appended to a biologically active parent sequence. That shared design is why they are frequently discussed together in the research-peptide literature.
Beyond the structural similarity they diverge: Semax is built on the ACTH(4-7) fragment and is studied chiefly in neurotrophic gene-expression models (BDNF/NGF) and ischaemia models in animals, while Selank is built on the immunopeptide tuftsin and is studied chiefly in GABAergic and immune gene-expression models.
At a Glance
| Semax | Selank | |
|---|---|---|
| Parent / origin | ACTH(4-7) core + Pro-Gly-Pro | Tuftsin (Thr-Lys-Pro-Arg) + Pro-Gly-Pro |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Molecular weight | ~813.9 g/mol | ~751.9 g/mol |
| CAS number | 80714-61-0 | 129954-34-3 |
| Primary mechanism studied | BDNF/NGF & TrkB neurotrophic signalling | GABAergic gene-expression models |
| Common research focus | Neurotrophic gene-expression and ischaemia models | GABAergic and immune gene-expression models |
Semax in Brief
Semax is a synthetic ACTH(4-7)-derived heptapeptide reported to lack hormonal (corticotropic) activity. In published animal and in-vitro studies it is most associated with measured changes in BDNF and NGF expression, the TrkB neurotrophic axis, and gene-expression changes in rodent ischaemia models. It is the more neurotrophin-focused of the two in the research literature.
See the full Semax research guide.
Selank in Brief
Selank is a synthetic tuftsin-derived heptapeptide studied primarily in GABAergic gene-expression models, with additional published measurements of hippocampal BDNF, serotonin metabolites, and immune-related gene expression in animal and cell models. It is the more GABAergic and immune-focused of the two in the research literature.
See the full Selank research guide.
Key Mechanistic Differences
- Different parent molecules, different systems: Semax originates from an ACTH fragment and is studied around the neurotrophin/TrkB system; Selank originates from tuftsin and is studied around the GABAergic system and immune signalling.
- Neurotrophic vs GABAergic emphasis: Semax's most-cited endpoints are BDNF/NGF expression and gene expression in ischaemia models (e.g. Dolotov 2006; Agapova 2007); Selank's are GABAergic gene expression and rodent behavioural measures (e.g. Volkova 2016).
- Immunomodulation is largely a Selank feature: Through its tuftsin lineage, Selank has been studied for changes in cytokine and inflammation-related gene expression (e.g. Kolomin 2011), a dimension not characteristic of Semax.
- Shared neurotrophin touch-point: Both peptides have been studied for hippocampal BDNF expression in rodent models, one reason they are often compared.
Why the Two Are Often Compared
Semax and Selank are often compared because their primary research focuses differ: Semax is examined in neurotrophic gene-expression models (BDNF/NGF, TrkB), while Selank is examined in GABAergic models. Both share the same Pro-Gly-Pro stabilising design and a common developmental origin, which makes them a natural comparison pair in the literature.
Frequently Asked Questions
What is the main difference between Semax and Selank?
They derive from different parent peptides and are studied for different mechanisms. Semax (from an ACTH fragment) is studied in neurotrophic gene-expression models (BDNF/NGF); Selank (from tuftsin) is studied in GABAergic and immune gene-expression models.
Why are Semax and Selank often compared?
They are frequently discussed as a pair because their primary research focuses differ, neurotrophic gene-expression models (Semax) and GABAergic models (Selank), and they share the same Pro-Gly-Pro structural motif and developmental origin.
Which one is associated with which research focus?
In the published literature, Semax is associated with neurotrophic gene-expression and ischaemia models (BDNF/NGF, TrkB), while Selank is associated with GABAergic and immune gene-expression models (GABA-related and cytokine gene expression). Both are supplied as lyophilised powder, ≥98% HPLC, for in-vitro laboratory research only.
Disclaimer: This information is compiled from published peer-reviewed literature and is provided for educational and research reference purposes only. It does not constitute medical advice. The peptides referenced here, sold by Enhanced Research Compounds, are intended exclusively for in-vitro research and laboratory use. They are not therapeutic goods, are not listed on the ARTG, and are not approved for human or animal consumption.