What Is Selank?

Selank is a synthetic peptide made of seven amino acids, built by extending a smaller natural peptide called tuftsin with a short, stability-boosting tail. Researchers in Russia have published most of the work on it, and Russian health authorities have registered it as a nonprescription drug there; no other major regulator has approved it for any use in people.

What Selank is built from

Selank's sequence is threonine-lysine-proline-arginine-proline-glycine-proline (Thr-Lys-Pro-Arg-Pro-Gly-Pro), with a molecular weight of roughly 752 daltons. The first four amino acids, Thr-Lys-Pro-Arg, are tuftsin itself, a naturally occurring peptide fragment that the body can clip from an antibody's heavy chain and that has been studied for decades as an immune signaling molecule. The last three, Pro-Gly-Pro, are an addition designed to slow the enzymes that would otherwise break the peptide down quickly once it reaches the bloodstream.

The research program behind Selank traces to the Institute of Molecular Genetics in Moscow; biochemist N.F. Myasoedov's name appears as a co-author on nearly every published Selank study, from the earliest clinical reports through more recent animal work, which is the clearest evidence of where the compound originated.

What has actually been tested, and in whom

The human data is small and almost entirely Russian. In a 2008 randomized comparison published in the Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, researchers led by A.A. Zozulia enrolled 62 patients with generalized anxiety disorder and neurasthenia, giving 30 of them Selank and 32 a comparison anxiolytic, medazepam, and scoring them on standard psychiatric rating scales (Hamilton, Zung, and the Clinical Global Impression scale). Both drugs produced similar reductions in anxiety ratings over the course of the trial, and the researchers also reported a blood marker tied to enkephalin breakdown that shifted more in Selank-treated patients with generalized anxiety disorder specifically.

A separate 2008 report from the same journal, led by O.N. Uchakina, looked at Selank's effect on the immune system in patients with anxiety-asthenic disorders. After 14 days of treatment, the researchers measured changes in the balance of two cytokine signaling pathways in blood serum, and in laboratory cell cultures found that Selank suppressed a specific interleukin in blood cells taken from patients with depression but not from healthy volunteers. The authors framed this as evidence that Selank has effects on immune signaling beyond its anxiolytic activity.

The animal literature is more recent and more mechanistic. A 2017 study in Behavioral Neurology, led by A. Kasian's group (with Myasoedov again a co-author), tested Selank in male rats under two weeks of unpredictable stress — a mix of food and water restriction, tilted cages, cold-water swimming and disrupted light cycles meant to model chronic stress. The researchers split 48 rats into stressed and non-stressed groups of six, each further divided into animals receiving saline, Selank alone, diazepam alone, or both together, and measured anxiety with the elevated plus maze, a standard rodent test that tracks how long a rat spends in the maze's open, unprotected arms versus its enclosed arms.

Under chronic stress, saline-treated rats showed the steepest drop in open-arm time by the end of the study. Selank alone and diazepam alone each softened that drop, with diazepam producing the larger effect on its own; the combination of Selank and diazepam kept open-arm time closest to each animal's pre-stress baseline and was the only group whose change from baseline was not statistically significant, meaning those rats behaved most like they had before the stress protocol began. In rats that were not stressed, Selank alone was the only treatment that did not produce a significant change in behavior across the study period, while diazepam alone and the combination did. The paper's own discussion is careful to note that Selank and diazepam were given by different routes (Selank into the nose, diazepam by mouth), that each group held only six animals, and that the result was never directly tested against diazepam alone under stress, so its suggestion that combining the two could allow a lower benzodiazepine dose is a discussion point rather than something the data directly measured.

Approved in Russia, not elsewhere

Russia's drug reference registry lists an active registration for Selank nasal drops (0.15% solution), filed under a 2025 renewal of an older registration number, held by the Moscow manufacturer Peptogen. The listing records it as a nonprescription drug, with an indication covering anxiety states, panic attacks, asthenia and stress-related sleep disruption in adults, and classifies it under the anxiolytic group of Russia's drug classification system.

In the United States, Selank acetate has a narrower, specific regulatory history. Legal trade coverage of FDA compounding policy reports that the agency had placed Selank acetate, listed under the code TP-7, in "Category 2" of substances nominated for pharmacy compounding under Section 503A of the Food, Drug and Cosmetic Act — a category reserved for substances with safety concerns, where the agency does not extend the no-enforcement policy it applies to Category 1 — and removed it from that category in September 2024. What's directly confirmed on FDA's own bulk drug substances page, current as of May 14, 2026: Selank does not appear in Category 1, 2 or 3 at all, so it currently sits outside the 503A compounding framework entirely rather than inside any approved or provisionally tolerated tier of it. The FDA, EMA and other major drug regulators have not approved Selank for any human use.

What's known versus what isn't

What's reasonably well established: Selank's chemical structure, its origin as a tuftsin derivative from a specific Russian research group, its current nonprescription registration in Russia, and the fact that a small number of Russian human trials and a larger body of rodent work have been published on it.

What's thin or missing: independent replication outside Russia is sparse, the published human trials are decades-old, small by modern standards, and compared Selank only against other drugs rather than placebo in some cases, and no randomized trial appears in a major international psychiatry or immunology journal. No dose-ranging study, no FDA-regulated Phase 1 safety trial and no large multi-site trial of Selank has been published anywhere, in Russia or elsewhere, as far as the public literature shows. The mechanistic claims that circulate about Selank online — effects on brain-derived neurotrophic factor, serotonin turnover, or broad immune modulation — mostly trace back to laboratory and animal studies, not confirmed human pharmacology, and the handful of human trials that do exist measured psychiatric rating scales and blood markers, not any of those specific mechanisms directly. Selank's own stability and distribution in the body once it leaves the nose is also not settled in the public literature, with published estimates varying widely.

What this means for researchers

Selank is a case study in how regulatory status and research maturity can diverge. It has a national drug registration and a multi-decade publication history, which gives it more documentation than many peptides sold as research chemicals, yet that history is concentrated almost entirely within one country's research and regulatory system. Readers evaluating Selank studies should weight the country of origin, the age and size of the human trials, and whether a given claim comes from the 2008 clinical literature or from later animal and cell-culture work addressing a different question.

For anyone checking regulatory claims directly, the FDA's own list of bulk substances nominated for compounding is a more reliable primary source than secondary summaries, and the same caution applies to any peptide moving in and out of that list's categories — removal from one category is not equivalent to approval. The Torrey Labs learning library and the journal's explainer on how peptide legality actually works cover that distinction in more detail for researchers tracking similar compounds.