At a Glance
Semax and Selank are often discussed together: both are short synthetic regulatory peptides developed within Russian research programs, both are studied in neuro contexts, and both are commonly grouped under nootropic peptide research. But they come from entirely different parent molecules — and that origin is what separates their research focus.
| Attribute | Semax | Selank |
|---|---|---|
| Compound class | Synthetic regulatory peptide | Synthetic regulatory peptide |
| Derived from | ACTH fragment (ACTH 4-10 region) | Tuftsin (immunomodulatory peptide) |
| CAS number | 80714-61-0 | 129954-34-3 |
| Peptide length | Short peptide | Short peptide |
| Primary research focus | Cognition & neuroprotection models | Anxiety-related & neuro-signaling models |
| Research category | Nootropic peptide research | Nootropic peptide research |
| Common research format | Lyophilized powder / nasal solution | Lyophilized powder / nasal solution |
| Intended use | Laboratory research only | Laboratory research only |
Origin & Structure
Semax is a synthetic peptide based on a fragment of ACTH (adrenocorticotropic hormone) — specifically the ACTH(4-10) region — with stabilizing modifications. Its research lineage ties it to cognition and neuroprotection studies.
Selank is a synthetic peptide based on tuftsin, a naturally occurring immunomodulatory peptide, again with stabilizing modifications. Its research lineage ties it to anxiety-related and neuro-signaling studies.
Both are short enough that they are studied intranasally as well as in standard in-vitro formats — see the Nasal vs Lyophilized comparison for the format distinction.
Research Context
The reason researchers compare Semax and Selank is that they occupy the same broad research neighborhood — short regulatory peptides studied against neuro pathways — while approaching it from different molecular origins. A study examining ACTH-fragment-derived effects would reach for Semax; a study examining tuftsin-derived effects would reach for Selank. Neither is a substitute for the other.
Which Should a Study Use?
Selection is driven entirely by the research question and the parent-peptide lineage a study is built around. Both belong to the nootropic peptide research area described in the Research Hub. They are reference compounds, not interchangeable tools.
Semax and Selank are sold strictly for laboratory and in-vitro research. They are not for human consumption, veterinary use, or any diagnostic or therapeutic application. This comparison is research reference material, not medical or dosing advice.