Research comparison
Selank vs Semax
Selank and Semax are routinely mentioned in the same breath: both are synthetic heptapeptides, both were developed in Russian research programmes, and both extend a natural parent sequence with a stabilising tripeptide. The symmetry of construction hides different parents and different research questions.
This page compares the two research profiles. The profiles carry the citations; nothing here is a claim about effects in people.
| Selank | Semax | |
|---|---|---|
| Category | Peptide | Peptide |
| Highest evidence | Early human — evidence level 3 of 4: Early human evidence Findings come from small, early-phase or observational human studies. These are typically short, sparsely replicated, and designed to examine tolerability or signal rather than to establish effect. | Early human — evidence level 3 of 4: Early human evidence Findings come from small, early-phase or observational human studies. These are typically short, sparsely replicated, and designed to examine tolerability or signal rather than to establish effect. |
| UK regulatory status | Experimental — UK regulatory status: Experimental — not authorised for human use in the UK A compound appearing in research literature that holds no UK authorisation for human use in any indication. | Experimental — UK regulatory status: Experimental — not authorised for human use in the UK A compound appearing in research literature that holds no UK authorisation for human use in any indication. |
| Research areas | Anxiety models; GABAergic signalling | Neuroprotection models; Neurotrophin signalling |
| Verified citations | 5 | 5 |
Selank
A synthetic heptapeptide derived from the immunomodulatory tetrapeptide tuftsin, studied chiefly in Russian anxiety research.
Selank is a synthetic heptapeptide built from the immunomodulatory tetrapeptide tuftsin extended with a tripeptide to improve metabolic stability. Proposed mechanisms include inhibition of enkephalin-degrading enzymes, modulation of GABAergic and monoaminergic gene expression, and effects on neurotrophin concentrations in rodent brain regions. No single pathway has been established as the basis of its reported clinical effects.
Semax
A synthetic heptapeptide derived from a fragment of adrenocorticotropic hormone, studied chiefly in Russian stroke research.
Semax is a synthetic heptapeptide combining the ACTH(4–7) fragment with a C-terminal tripeptide that confers resistance to enzymatic degradation. It is a melanocortin derivative lacking the corticotropic activity of the parent sequence. Proposed mechanisms centre on modulation of neurotrophin signalling and broad transcriptional effects on inflammatory and neurotransmitter gene clusters. These pathway assignments derive chiefly from rodent transcriptomic work and remain proposed rather than established in humans.
How the research differs
Different parent sequences
Selank is built from tuftsin, an immunomodulatory tetrapeptide. Semax is built from the ACTH(4–7) fragment of adrenocorticotropic hormone, engineered to lack the corticotropic activity of the parent. Same construction principle — natural fragment plus stabilising tail — applied to unrelated starting points.
Different mechanisms under investigation
The Selank literature investigates inhibition of enkephalin-degrading enzymes and modulation of GABAergic and monoaminergic signalling, chiefly in anxiety models. The Semax literature centres on neurotrophin signalling, chiefly in neuroprotection and stroke models. The overlap in origin does not carry into the mechanisms studied.
A shared limitation worth knowing
Both evidence bases are predominantly Russian-language and Russian-run, with limited independent replication elsewhere — a point both profiles make explicitly in their study-limitations sections. Neither compound is an authorised medicine in the UK, and both profiles record that status with a cited source.