Selank Complete Guide: What the Anxiety Research Shows

What Is Selank, and What Does Selank Do?

Selank is a lab-made peptide studied in Russia as a treatment for anxiety. In one Russian trial, its calming effect was similar to that of medazepam, a benzodiazepine. Benzodiazepines are a class of calming drugs. No English abstract we found gives a dose of Selank for people. The doses on this page come from animal and cell studies.

Selank is a heptapeptide. That means a chain of seven amino acids. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro (Zozulya). It is built on tuftsin, a natural four-amino-acid peptide with the sequence Thr-Lys-Pro-Arg (Semenova). Tuftsin is a natural immunomodulator, a signal that tunes the immune system (Siebert). A rat study calls Selank a synthetic derivative of tuftsin that is stable against tissue peptidases (Semenova). Peptidases are enzymes that cut peptides apart.

Much of the selank peptide research comes from Moscow. The authors include groups at the Institute of Molecular Genetics of the Russian Academy of Sciences (Volkova). Others work at Moscow's Mental Health Research Center (Medvedev). A US review takes a cooler view. It calls phenibut and Selank poorly studied Russian drugs with GABAergic mechanisms (Doyno and White). GABAergic means acting on GABA, the brain's main calming signal.

This content is for educational purposes only and is not medical advice. Nothing here is a guide to research use or to treatment. A qualified clinician can advise on any health decision.

What Is Selank Peptide Used For in Studies?

Three of the human studies we found test it in anxiety disorders. A fourth scanned the brains of healthy volunteers. Each one below is from Russia, and each English abstract is short.

Generalized anxiety disorder. Generalized anxiety disorder (GAD) means lasting, hard-to-control worry. One Russian trial set selank against medazepam in 62 patients with GAD or neurasthenia. Neurasthenia is an older diagnosis of lasting fatigue and nervous exhaustion. Thirty patients took selank and 32 took medazepam. The anxiolytic effects of both drugs were similar. Anxiolytic means anxiety-reducing. Selank also had antiasthenic and psychostimulant effects. Antiasthenic means it eased weakness and fatigue. Psychostimulant means it raised mental energy.

Phobic, anxiety and somatoform disorders. Somatoform disorders are physical symptoms with no clear physical cause. One study compared selank with phenazepam, a benzodiazepine, in 60 patients (Medvedev). The authors report a pronounced anxiolytic effect and a mild nootropic effect. Nootropic means it helped thinking. The anxiolytic effect lasted for a week after the last dose.

As an add-on to a benzodiazepine. A second study gave 30 patients phenazepam alone and 40 patients phenazepam with selank (Medvedev). The add-on group reached the phenazepam effect sooner on the HDRS, a symptom rating scale. It also had fewer of phenazepam's unwanted effects.

Brain scans in healthy people. A brain-scan study tested 52 healthy people before and after Selank, Semax or a placebo, a dummy treatment (Panikratova). It used resting-state fMRI, a scan of brain activity at rest. The authors found changes in links between the right amygdala and the right temporal cortex. The amygdala is a brain region that helps regulate anxiety.

How Does Selank Work in the Brain?

No single mechanism is proven in people. Lab and animal studies point to five areas. Each is labelled below with the species it was tested in.

1. GABA, the brain's calming signal

GABA is your brain's main quieting neurotransmitter, a chemical messenger between nerve cells. Mohler 2012 reviewed the GABA system in anxiety and depression. That review is not about Selank. It reports that drugs acting on certain GABA-A receptor subtypes can beat classical benzodiazepines on side effects. They lack sedation and have much reduced or absent dependence liability.

For Selank itself, the GABA work is in rats. A study in Frontiers in Pharmacology measured gene activity in the frontal cortex of rats. The rats got Selank or GABA at 300 mcg per kg of body weight. The team tracked 84 nerve-signalling genes and could measure 77 of them. Of those 77, 29 changed 1 hour after Selank (45 counting Selank or GABA). After 3 hours, 17 changed after Selank (22 counting either). The authors say one possible mechanism is allosteric modulation of the GABAergic system. Allosteric means nudging a receptor from a side site, not switching it on directly. A study on rat brain membranes reported that Selank acts as a positive allosteric modulator of GABA binding (Vyunova).

2. Serotonin

Serotonin is a messenger chemical tied to mood. In rats, one Selank injection of 300 mcg per kg raised serotonin turnover in the hypothalamus and brain stem. The hypothalamus is a brain region that steers hormones. That lasted from 30 minutes to 2 hours (Semenova). Another rat study first lowered serotonin with a drug called PCPA. In those rats, Selank raised serotonin turnover in the brain stem 30 minutes after injection, while tuftsin did not (Semenova).

3. BDNF and the hippocampus

Brain-derived neurotrophic factor, or BDNF, is a protein that helps nerve cells grow and connect. Selank given in the nose regulates BDNF expression in the rat hippocampus. That is the finding the study's title reports. Expression here means how much BDNF the cells make. The hippocampus handles learning and memory. In a later rat study, Selank at 0.3 mg per kg a day for 7 days was injected into the belly cavity. It prevented an alcohol-driven rise in BDNF and the memory problems seen in alcohol withdrawal (Kolik). Our Semax complete guide covers Semax, a related Russian peptide.

4. Enkephalin-degrading enzymes

Enkephalins are your body's own opioid peptides. They help handle pain and stress. In human plasma, Selank slowed the enzymes that break them down. A tritium-labelled assay in human plasma found it is more specific for carboxypeptidases and dicarboxypeptidases. The assay tracked enkephalin tagged with tritium, a radioactive form of hydrogen. Plasma is the liquid part of blood. Those are two kinds of enzymes that chew up enkephalins. That was a test-tube study on blood plasma, not a study in patients.

An early study found that patients with generalized anxiety had a shorter enkephalin half-life in their blood. Half-life is how long half of a substance lasts. In plasma, Selank blocked this breakdown, with an IC50 of 15 micromolar, a measure of strength in solution (Zozulya). IC50 is the strength needed to block half the activity. In mice, 100 mcg per kg eased anxiety in one strain but not another (Sokolov). Both teams suggest this enzyme effect may explain part of Selank's anti-anxiety action.

5. Immune signals and the tuftsin link

Because it is built on tuftsin, Selank has been tested on immune signals. One study of patients with anxiety-asthenic disorders found two things. In vitro, meaning in a dish, the drug shut down IL-6 gene activity in blood cells from patients with depression. It did not do so in healthy controls. In the same cultures, the amount of IL-6 protein rose. IL-6 is an inflammation signal. In vivo means in the body. In that test, the Th1/Th2 cytokine balance shifted in the serum of patients with GAD and neurasthenia who took it for 14 days. T-helper cells, or Th cells, steer the immune response. Cytokines are the signal proteins they use. In a mouse flu study, Selank raised interferon-alpha gene activity, an antiviral signal. It did not change TNF-alpha, another inflammation signal (Ershov).

What Selank Dosage Chart Do Published Studies Report?

The chart below lists every Selank dose we found in a PubMed abstract. All of them are from animals or from cells. The doses are per kilogram (kg) of body weight. None of these studies set a dose for people.

Is there a selank peptide dosage for people?

Not in any English abstract we read. The Russian trials above gave Selank to patients. Their English abstracts do not state the dose, the route or how often it was given. PubMed tags the medazepam trial with both nasal and oral use. The abstract itself does not say which route was used for which drug.

Where do online selank dosing figures come from?

Doses in micrograms per spray, with on and off cycles, circulate on vendor and forum pages. We found no primary source for any of them. The chart above is the full list of doses we could trace to a published study.

Is There a Selank Nasal Spray Dose for People?

No published human dose for a selank nasal spray appears in the abstracts we read. Giving it in the nose is a route several animal studies used. The rat BDNF study gave it in the nose (Inozemtseva). So did two rat gene studies. One used 300 mcg per kg (Volkova). The other used 200 mcg per kg (Kolomin). Another study gave it in the nose to rhesus monkeys whose behaviour was disturbed during neurosis (monkey study). It reported that fear and aggression went away.

Route changed the result in one mouse study (Vasil'eva). Both routes eased anxiety, but only in the more anxious mouse strain. Given into the belly cavity, Selank raised GABA receptor binding in the frontal cortex by 38%. Given in the nose, it raised NMDA receptor binding in the hippocampus by 23% instead. NMDA receptors are linked to learning.

What Are the Main Selank Benefits in the Research?

The selank benefits reported so far fall into three groups. Each rests on a different kind of evidence.

In patients. Russian trials report less anxiety, with a similar effect to medazepam (Zozulia). The medazepam trial also reports antiasthenic (anti-fatigue) and psychostimulant effects. The phenazepam trial reports a mild nootropic effect and better quality of life (Medvedev). As an add-on, it lowered phenazepam's side effects (Medvedev).

In animals. In rats, one injection given during training increased how stable the learned memory was, tested up to 30 days later (Semenova). In rats with a damaged dopamine system, Selank lowered anxiety on a maze test (Slominsky). In mice with flu, it had an antiviral effect (Ershov).

In the lab. The enzyme work was done in human plasma, not in patients. The gene work was done in rat and mouse tissue.

What are the selank peptide benefits the research actually supports?

Keep the groups apart. The anti-anxiety effect in Russian patients is the best-supported claim. Even that rests on a few trials with short English abstracts. The BDNF, gene and serotonin work sits in animals. We found no published week-by-week timeline of effects in people. One timing fact does come from a trial: the anti-anxiety effect lasted a week after the last dose, in the first phenazepam trial above.

What Do Studies Say About Selank Peptides With Other Drugs?

Only a few pairings have been studied. The table lists them.

Selank with Semax

Semax is a related Russian peptide. The two studies above tested each one on its own, not the two taken together. We found no study of the two given at the same time. We break the head-to-head down in our Semax vs Selank comparison. For Semax doses, see our Semax dosage guide for nasal spray and injection.

Selank with BPC-157 or TB-500

No study we found gave Selank with BPC-157 or TB-500. A recent orthopaedic review lists all three among therapeutic peptides (Rahman). It notes a current lack of clinical trials. The FDA found insufficient clinical safety information to characterize the safety profile of BPC-157 (FDA briefing). For TB-500, the FDA found no clinical studies or human exposure data by any route (FDA briefing). See our BPC-157 dosage guide and TB-500 dosage guide.

What Are the Selank Side Effects?

The English abstracts give little side-effect detail. An early paper by the Selank research group says it does not cause side effects typical of most anxiolytics (Zozulya). That is the developers' own summary. The first phenazepam study measured tolerability but its abstract lists no Selank side effects (Medvedev).

The add-on study is more specific (Medvedev). Adding selank lowered these phenazepam side effects:

• Attention and memory impairment.
• Asthenia, meaning weakness and lack of energy.
• Sedation and longer sleep.
• Sexual disturbances and emotional indifference.
• Orthostatism, meaning dizziness on standing.

What is not known. We found no long-term human safety study in PubMed. We found no human study in pregnancy or breastfeeding. A study on mouse embryonic stem cells concluded the peptides tested caused no toxic effect. Even so, Selank at 100 micromolar cut the share of cells becoming GABA neurons by 61% (Kobylyanskii). That is a cell test, not a pregnancy study. The US review calls Selank poorly studied (Doyno and White).

How it is sold. The same review says phenibut and Selank are sold to US consumers as dietary supplements. SSRIs are a common class of antidepressants. No study we found tested Selank with them. A qualified clinician can advise on drug interactions.

Is There Selank Withdrawal When You Stop?

No abstract we read reports withdrawal symptoms after Selank was stopped. In the first phenazepam trial, the anti-anxiety effect lasted for a week after the last dose.

Two studies look at withdrawal from other drugs. One Russian trial added selank to phenazepam, a benzodiazepine, in patients with anxiety-phobic, hypochondriac and somatoform disorders. The pairing cut the unwanted effects phenazepam causes, attention and memory impairment, asthenia and sedation among them. That held during the course of treatment and after the tranquilliser was withdrawn.

In rats dependent on morphine, one Selank injection of 0.3 mg per kg cut the morphine withdrawal score by 39.6% (Konstantinopolsky). Diazepam at 2 mg per kg cut it by 49.3%. That is a rat study of opioid withdrawal, not of stopping Selank.

How Does Selank Compare With Benzodiazepines and SSRIs?

Benzodiazepines are the only comparison tested in patients. The table sets out those trials.

Against benzodiazepines. One Russian trial found a calming effect similar to medazepam. None of the three abstracts reports on dependence.

Against SSRIs and L-theanine. We found no study comparing Selank with SSRIs or with L-theanine, an amino acid sold as a supplement. Any head-to-head claim about them has no trial behind it.

Against Semax. Semax is a related peptide. The brain-scan study tested both (Panikratova). It found some shared and some separate effects of the two.

Where Should You Buy Selank Peptides?

The supplier matters. We only list sources that publish an independent, per-batch certificate of analysis. See the ones that clear it. Our supplier vetting guide shows you how to run the same checks yourself.

Selank has a small body of Russian clinical research and a larger body of animal work. The anti-anxiety findings in patients are its strongest evidence. The rest is still early.

This article is for educational purposes only. A qualified clinician can advise on any health decision.