Short answer
Semax and Selank are both short synthetic peptides from Russian neuropeptide research. Semax is derived from a fragment of adrenocorticotropic hormone and is studied mainly in neurotrophic and cerebral ischaemia models. Selank is derived from the immunomodulatory peptide tuftsin and is studied mainly in anxiety related and immune signalling models. They share a delivery format, not a mechanism.
Semax and Selank are often listed next to each other because both came out of the same Russian research programme and both are studied in neuroscience models. They are different molecules with different parent peptides and different literature. This is the comparison as the published record supports it.
Where does each peptide come from?
Semax is a synthetic heptapeptide built from the ACTH 4 to 7 fragment with an added proline glycine proline sequence, which was introduced to slow enzymatic breakdown. It carries no corticotropic activity of its own in the published models.
Selank is a synthetic heptapeptide built from tuftsin, a short immune signalling peptide, with the same stabilising tail approach. Different parent, different research question, similar design logic.
| Property | Semax | Selank |
|---|---|---|
| Parent molecule | ACTH 4 to 7 fragment | Tuftsin |
| Length | Heptapeptide | Heptapeptide |
| Main research pathway | Neurotrophic signalling, cerebral ischaemia models | Anxiety related behaviour, cytokine measures |
| Formats supplied | 5mg and 10mg vial, nasal spray | 5mg and 10mg vial, nasal spray |
| Marketing authorisation in the EU | None | None |
Which research pathways are studied?
Semax literature is concentrated on neurotrophic factor expression, in particular brain derived neurotrophic factor, and on rodent models of cerebral ischaemia and cognitive load.
Selank literature is concentrated on anxiety related behaviour in rodent models and on cytokine and interleukin measurements, reflecting the immune origin of tuftsin.
Both bodies of work are largely preclinical, mostly published in Russian language journals, and neither compound holds a marketing authorisation in the European Union.
How do the formats compare?
- Semax 5mg and 10mg lyophilised vials, plus a prepared nasal spray at 10mg.
- Selank 5mg and 10mg lyophilised vials, plus a prepared nasal spray at 10mg.
- Vials let the researcher set concentration with the reconstitution calculator; sprays arrive already in solution.
- Vial mass differs between products, so recalculate rather than reusing a figure from another compound.
What do the two have in common?
Design lineage and handling. Both are short synthetic peptides with a stabilising tail, both were developed in the same institutional programme, and both are supplied as research compounds with the same storage and documentation requirements.
That shared background is the reason they are confused. It is not evidence that they act through the same pathway.
Research use only
Semax and Selank are supplied by Vitality Peps for in vitro laboratory research only. Not for human or veterinary consumption. Nothing above is dosing guidance.
Frequently asked questions
What is the difference between Semax and Selank?
Their parent molecules. Semax is based on a fragment of adrenocorticotropic hormone with a proline glycine proline tail, and the literature around it concerns neurotrophic signalling and models of cerebral ischaemia. Selank is based on tuftsin, an immune signalling peptide, and its literature concerns anxiety related behaviour models and cytokine measures.
Are Semax and Selank studied together?
Both appear in the same research programme and are sometimes examined in parallel in the same publications, but controlled evidence for a combined protocol is thin. Nothing in the published record establishes an interaction profile between them.
Do they come in the same formats?
Vitality Peps supplies both as lyophilised vials and as nasal sprays. The vial is the format used when a study needs the researcher to set the concentration; the spray is a fixed prepared solution. Format choice does not change what the literature says about either compound.
How are they handled in the lab?
Identically. Store the lyophilised vial cold and dark, reconstitute with bacteriostatic water, keep the reconstituted solution refrigerated and calculate concentration per vial mass rather than copying a figure from another compound.
For research purposes only. Not for human consumption. This article is educational and references published laboratory research; it is not medical advice and does not describe an approved use of any compound.