Research digest · Anxiolytic heptapeptide
Selank is a seven-amino-acid peptide studied as a calm, non-sedating anxiolytic.
A measured summary of the published research — what the GABAergic and enkephalinase studies actually measured, and where the evidence is still thin. Organized, sourced, and free of hype.
The short version
Selank is a small lab-made peptide — a chain of seven amino acids — first developed in Russia and studied as a way to calm anxiety without the heavy, drugged feeling of older sedatives. In research, it appears to work mainly two ways: it nudges the brain's main "calm-down" chemical system (GABA), and it slows down enzymes that break apart the body's own feel-better molecules (enkephalins). Animal studies and a small number of Russian clinical studies report a steadier, less anxious state, with no sign of the sedation or dependence that benzodiazepine drugs can cause. Most of the data is from rats and from one region's research groups, so it is interesting but far from settled. Selank is not approved by the FDA. People also report calmer, sharper days — and a real share who feel nothing at all — and what they report, including the downsides, is on the effects page.
What the Selank literature has established
Selank (sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, also designated TP-7) is a synthetic analogue of tuftsin — a short natural peptide (a fragment cut from an antibody molecule) that the body uses in immune signaling. Researchers extended tuftsin's sequence with three extra residues (Pro-Gly-Pro) so it survives longer in the body before enzymes break it down [13].
Its anxiolytic activity centers on the GABA system, the brain's primary inhibitory (calming) network. A review of the binding data describes Selank as a positive allosteric modulator of GABA receptor binding — meaning it enhances the receptor's response from a secondary site rather than switching it on directly — with a subtype-selective, concentration-dependent profile that differs from benzodiazepines [1]. In rat frontal cortex, a single 300 µg/kg dose shifted the expression of 45 genes at one hour and 22 at three hours, and those shifts correlated positively with the changes GABA itself produces [4].
A second mechanism runs through the body's natural opioid system. In human plasma in vitro, Selank dose-dependently inhibited enkephalin-degrading enzymes with an IC50 of roughly 15 µM, which would slow the breakdown of endogenous enkephalins (the body's own anti-stress peptides) [2]. When researchers blocked opioid receptors with naloxone in rats, Selank's behavioral effect disappeared — direct evidence the opioid system is involved [9].
Calm without the sedation trade-off
The finding that draws the most attention is the absence of a familiar trade-off. Benzodiazepines reduce anxiety but bring sedation, cognitive dulling, and dependence. In Russian clinical studies of generalized anxiety disorder, intranasal Selank produced an anxiolytic effect comparable to a benzodiazepine comparator — but without the sedation, cognitive impairment, or withdrawal signal [5].
This is not a claim that Selank treats any anxiety disorder. It is a description of what specific studies reported, in selected patients, under medical supervision, in a single research tradition. The honest framing matters: the human evidence base is far thinner than for approved anxiolytics, and independent replication outside Russia is limited.
More than an anxiolytic: neurotrophic and immune signals
The research record extends past anxiety. After intranasal dosing, Selank increased BDNF (brain-derived neurotrophic factor, a protein that supports neuron survival and learning) in the rat hippocampus — a result that ties the peptide to neuroplasticity and helps explain its nootropic-like effects in animal tasks [3].
Because Selank descends from tuftsin, it also carries immune activity. In patients with anxiety-asthenic disorders it shifted the Th1/Th2 cytokine balance and modulated IL-6, leading researchers to describe it as an immunomodulator as well as an anxiolytic [6]. This breadth — calming, neurotrophic, and immune-modulating from one small molecule — is itself a recurring theme in the literature, and a reason the compound remains a research subject.
How to read this site
Each page summarizes a slice of the published record in plain language and cites it. Selank research covers the mechanism and key studies in depth. Selank effects is the honest account of what people report — the upsides, the downsides, and the common non-response — clearly separated from the cited science. The dosage page describes what was administered in studies, never a human recommendation. The Selank vs Semax page keeps two often-confused peptides distinct, and the Selank half life page covers its rapid metabolism. Every figure on every page maps to a numbered source on Selank references.