Tuftsin, extended for stability
Tuftsin is a four-residue fragment of an antibody, known since the 1970s for its role in immune signalling. Selank takes that fragment and adds three residues to it, a modification intended to slow how quickly enzymes break it down.
That design tells you something about the research question. The point was never the immune role of tuftsin on its own; it was whether a stabilised version would persist long enough to study effects on the central nervous system.
Readers who search what is selank usually want to know whether the anxiolytic reputation holds up, and the useful first move is to separate the design of the molecule from the strength of the evidence behind it. The design is clever; the evidence is thinner than the reputation suggests.
What the studies actually measured
The published work looks at anxiety-related behaviour in animal models and, in a smaller set of studies, in people. Proposed mechanisms involve GABAergic signalling and expression of brain-derived neurotrophic factor, both measured indirectly.
Sample sizes in the human work are small and the studies come from a limited number of groups. That is the honest summary, and it is why we describe it as a compound studied in anxiety research rather than an anxiolytic.
Both proposed mechanisms are inferred from downstream markers rather than observed directly, which is usual for neuropeptides and still worth naming. A shift in a marker is consistent with a mechanism; it is not the same as having demonstrated one, and the human studies are too small to close that gap.
| Base sequence | Tuftsin fragment, extended |
| Length | 7 amino acids |
| Origin | Synthetic, Russian research |
| Proposed targets | GABAergic signalling, BDNF expression |
| Formats | Peptide pen and nasal spray |
| Purity | ≥ 99% (HPLC) |
| Evidence base | Animal models and small human studies |
| Category | Research use only |
These are handling and identity facts. They carry no claim about results.
Why it appears as a nasal spray
Seven residues is short enough for the nasal route to be worth investigating, which is why selank shows up in that format alongside the pen. The mucosal route appears far more often in this research area than anywhere else in the catalogue, and chain length is the reason.
Which format suits your work depends on what you are comparing. Neither is presented here as better than the other.
The wider study record sits behind the results indexed on PubMed, and reading it shows how much of the format question is settled by chemistry rather than by preference: a sequence has to be short before the mucosal route is worth testing at all. Where that ceiling falls, and why it rules out most of this catalogue, is set out on the nasal spray format page.
Selank beside the other Russian neuropeptides
Selank rarely appears alone in the literature. It is usually discussed alongside a small family of synthetic neuropeptides from the same research tradition, and reading them together makes the shared assumptions easier to see. The file on DSIP is a useful comparison for how a confident name can outrun a thin evidence base.
One practical point applies to any peptide you open more than once: repeated warming and cooling is harder on a solution than steady cold storage. The freeze-thaw page explains the mechanism, and it weighs more for a spray in regular use than for a vial that stays sealed.
Selank in the catalogue
Purity is confirmed at 99% minimum before release; ask for the certificate matching your batch.
Where Selank fits in
Three related pages, for the context this article assumes.
About Selank
The questions that come up in almost every enquiry.