Intranasal Delivery in Neuropeptide Research

The short version

nasalpeptides is a literature desk, not a clinic or a store. It reads the published research on three neuropeptides — short chains of amino acids that act as signaling molecules in the brain — that share an unusual property: each has been studied, at least in part, using intranasal administration, meaning the compound is delivered through the nose rather than by injection or in pill form.

The nose sits close to the brain, and researchers have long asked whether a compound sprayed into the nasal cavity can reach neural tissue more directly than one absorbed elsewhere in the body — a route sometimes called nose-to-brain delivery. Semax, Selank, and DSIP were each tested this way in at least one study cited below, though none has an approved human indication in the United States, and this site describes none of them as something to use.

This page and the three peptide pages report what was studied — in which species, at what dose, and with what result — never what a person should do. Every factual claim on this site carries a numbered citation, gathered on the references page.

Why the nose-to-brain route

The organizing idea for this desk is delivery route, not drug class. Semax, Selank, and DSIP have almost nothing in common pharmacologically — one is an ACTH fragment, one is a tuftsin analog, one is an unclassified nonapeptide with no identified receptor — but researchers studying each of them have repeatedly reached for the same experimental choice: intranasal administration.

In a rat study, a single 50 microg/kg intranasal dose of Semax produced rapid, region-specific shifts in neurotrophin gene expression within hours ^[3]. Intranasal Selank, given to rats, was separately shown to regulate BDNF expression in the hippocampus ^[9]. And in a rodent stroke model, intranasal DSIP significantly improved motor-function recovery by day seven while infarct volume was not significantly different from vehicle — a pattern the study's authors read as neuroprotective rather than lesion-limiting ^[17].

Three pharmacologically unrelated peptides, one shared experimental route. That is the thread this desk follows, and it is strictly a research thread: none of the intranasal dosing figures above describes a routine for a person, and this site names no human nasal-spray protocol for any of the three.

What are research peptides?

Peptides are short chains of amino acids — smaller than proteins, but built from the same building blocks. The three compounds covered here are neuropeptides: signaling molecules that act in or on the nervous system, distinct from the metabolic and hormonal peptides other research desks cover.

None of the three is an FDA-approved drug in the United States. Semax and Selank are registered pharmaceuticals in Russia for specific neurological and anxiety-related indications; DSIP has never been approved anywhere, despite carrying an International Nonproprietary Name, Emideltide. In the US, all three circulate as unscheduled research chemicals — sold for laboratory use, with no requirement that a given supplier's material actually contain what the label claims, at the purity claimed. This site reports what peer-reviewed literature has found in animal and small human studies; it does not endorse, sell, source, or recommend obtaining any of them.

How these three compare

• Semax is a stabilized ACTH(4-7) fragment researched mainly for neuroprotection, cognitive performance, and mood, with the deepest evidence base of the three coming from Russian cerebral-ischemia and spinal-cord-injury models ^[1][2][5].
• Selank is a tuftsin-derived heptapeptide researched as a non-benzodiazepine anxiolytic, with mechanistic work pointing toward GABA-receptor modulation and enkephalinase inhibition rather than classical sedation ^[6][7].
• DSIP is the lead compound on this desk — an endogenous nonapeptide discovered in 1977 whose sleep-promoting reputation is, by a 2006 review's own account, "extremely poorly documented and still weak" outside a handful of small studies ^[12][16].

Despite their different mechanisms, the three share the intranasal-delivery thread this desk is built around, and each carries its own uncertainty: a single-region evidence base, thin human data, and — for DSIP most acutely — no identified receptor after nearly fifty years of study. Compare the three side by side, or read a peptide page in full.