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Peptide Guide · Brain, mood and sleep

Selank

Thr-Lys-Pro-Arg-Pro-Gly-Pro, a tuftsin analogue (TP-7)

Most anxiety medicines work by turning down the brain’s alarm. Selank comes from an unexpected place, an immune peptide, and Russian researchers have studied it alongside benzodiazepines as well as in their place.

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Studied for
Anxiety, stress and cognition
Evidence
Human trials
Taken as
As prescribed by a clinician
Studied for
Anxiety, stress and cognition
Evidence
Human trials
Taken as
As prescribed by a clinician
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Selank, in short

Selank is a seven-amino-acid peptide built on tuftsin, a short immune peptide, and developed in Russia as an anxiety medicine. Receptor-binding work suggests it modulates GABA receptors, and it slowed the breakdown of enkephalins, the body’s own calming peptides, in blood samples. Small Russian trials found anxiety relief comparable to benzodiazepines, with less fatigue, but independent human data are scarce.

Medically reviewed by Robert Lufkin, MD (opens in a new tab)

Chief Medical Officer, Vitals Vault · Updated October 29, 2026 · 18 sources

At a glance

Human trials
Type
Synthetic heptapeptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro3
Based on
Tuftsin, a short immune-modulating peptide59
Studied for
Generalized anxiety, neurasthenia, stress and memory1115
Main targets
GABA signalling, enkephalin breakdown, BDNF, immune cytokines32510
Origin
Developed in Russia; human studies are mainly Russian18
FDA status
Not approved. Listed on FDA’s compounding safety page17

Before you consider Selank

  • Safety

    Small Russian trials checked tolerability, but they do not show long-term safety. FDA says it lacks human safety information on selank acetate.1217

    Side effects and safety
  • Legal status

    Not FDA approved. It is not one of the six peptides covered by FDA’s October 2026 policy, so there is no standard US prescription form.1718

    FDA status
  • How it’s taken

    In the studies, Selank was given by injection or into the nose. There is no standard US prescription form.6817

    Forms and dosage

How does Selank work?

Selank seems to work in several ways. The best evidence is for the brain’s calming system.

  • Helps the brain’s brake

    In lab tests, Selank helped the brain’s main calming signal land more easily. Benzodiazepines act on the same system.34

  • Protects calming peptides

    Selank slowed the enzymes that break down enkephalins, the body’s own calming peptides. They broke down faster in people with anxiety.21

  • Shifts brain and immune signals

    In rats, it changed a brain growth signal in memory and mood areas. In people with anxiety, it shifted immune signals in the blood.5610

Selank benefits: what it is studied for

The human evidence is small, mostly Russian and mostly from the groups that developed Selank. Animal data fill in the mechanism.

  1. Human study01

    Anxiety

    In a Russian trial of 62 people with generalized anxiety or neurasthenia, Selank and the benzodiazepine medazepam had similar anxiety relief. Selank also reduced fatigue.1

  2. Human study02

    Fewer benzodiazepine side effects

    In a 2015 study of 70 people, adding Selank to the benzodiazepine phenazepam brought relief sooner and reduced sedation, memory problems and other side effects.12

  3. Animal study03

    Memory under stress

    In rats, Selank prevented the memory and attention problems that develop during alcohol withdrawal.5

What the research shows

Human trials
  1. 1 · Cells in a lab Studied

    Boosted calming-signal binding in receptor tests and slowed enkephalin-breaking enzymes in blood samples.32

    Shows a mechanism

  2. 2 · Animals Studied

    In rats, it changed the activity of 45 brain genes and prevented memory problems during alcohol withdrawal.45

    Shows an effect in a body

  3. 3 · People Studied

    Small Russian trials found anxiety relief similar to benzodiazepines. None was a large placebo-controlled trial.111

    Shows it works in people

The evidence level is human trials of limited quality. The clinical work is small, run in Russia and published mostly by developer-affiliated groups. The mechanism data are from rats and cells. None of the studies cited here is a large placebo-controlled trial or an independent replication outside Russia.1124

The full guide to Selank

9 min read · Medically reviewed by Robert Lufkin, MD

In this guide

  1. 1How an immune peptide became an anxiety medicine
  2. 2How Selank works: GABA, enkephalins and gene switches
  3. 3Still an immune peptide at heart
  4. 4Selank for anxiety: what the trials found
  5. 5Selank and benzodiazepines: the side-effect finding
  6. 6Selank, memory and the anxious brain
  7. 7What we actually know in people
  8. 8Selank side effects and safety
  9. 9Labs that find what is feeding the alarm
  10. 10Is Selank FDA approved? Where it stands in 2026
  11. 11What this means for you
  12. 12What to expect
  13. 13Key studies
  14. 14Myths and evidence

01 / 11

How an immune peptide became an anxiety medicine

Why would anyone look for an anxiety medicine inside the immune system? The story starts with tuftsin, a tiny four-amino-acid peptide discovered by the biochemist Victor Najjar that acts on phagocytes, the immune cells that swallow bacteria and debris. In 1999, a review marking 30 years of tuftsin research listed effects well beyond immunity, including antimicrobial, antiviral and antitumor activity, and effects on the brain.

A team in Moscow took tuftsin’s sequence, Thr-Lys-Pro-Arg, and added Pro-Gly-Pro to the end, a tail usually described as slowing breakdown in the body. The result was a seven-amino-acid peptide they called Selank, framed from the start as an anxiolytic. The same tail ends Semax, a sibling peptide from the Institute of Molecular Genetics in Moscow.

Their goal was a calmer kind of anxiety medicine. Benzodiazepines, the class that includes diazepam, work quickly but bring sedation, memory problems and dependence. The Moscow researchers framed Selank as a mild agent, part of a growing interest in neuropeptides that might ease anxiety with fewer of those costs.

Over the next two decades they tested it in cells, rats and small groups of patients. The resulting picture is unusual. Selank appears to touch the GABA system, the enkephalin system, BDNF and the immune system all at once, and one of its most interesting human findings involves working alongside a benzodiazepine.159314

02 / 11

How Selank works: GABA, enkephalins and gene switches

GABA is the brain’s main braking signal. Benzodiazepines work by making GABA receptors respond more strongly when GABA arrives. In 2018, receptor-binding experiments from Selank’s home institute found that Selank also boosts GABA binding as a positive allosteric modulator, meaning it changes the receptor’s shape so the natural signal lands more easily. The authors suggested this effect depends on receptor subtype and concentration.

Gene studies point the same way. In a 2016 rat study comparing Selank with GABA, 45 of 84 neurotransmission genes in the frontal cortex changed activity an hour after dosing, and 22 three hours after. At one hour, the changes after Selank correlated with the changes after GABA itself, which the authors read as further evidence of a GABA-linked mechanism.

The second thread runs through enkephalins, small peptides the body makes to dampen pain and stress. In a 2001 study, people with generalized anxiety disorder broke down enkephalins unusually fast, while people with panic disorder and agoraphobia did not. Selank inhibited the enzymes responsible in a dose-dependent way, and it did so more strongly than two standard enzyme blockers used in the lab.

That finding came back in a 2008 trial. Patients with generalized anxiety and neurasthenia started with a shortened enkephalin half-life, and the shortening tracked how long and how severely they had been ill. During treatment with Selank, enkephalin half-life rose. It is a rare case in this field where a proposed mechanism was measured in the same patients as the clinical result.3421

In a 2016 rat study comparing Selank with GABA, 45 of 84 neurotransmission genes in the frontal cortex changed activity an hour after dosing, and 22 three hours after.

03 / 11

Still an immune peptide at heart

Selank never lost its tuftsin roots. In a 2008 study, researchers exposed blood cells to Selank in a dish. In cells from people with depression, it completely suppressed the gene for IL-6, an inflammatory messenger. In cells from healthy people, it did not. Yet the amount of IL-6 protein in the patients’ cell cultures rose with Selank, so the picture is mixed rather than simply anti-inflammatory.

The same team measured cytokines in the blood of people with generalized anxiety and neurasthenia who received Selank. The balance between Th1 and Th2 signals, two arms of the immune response, shifted during treatment. The authors proposed that Selank could act as an immunomodulator in anxiety with fatigue, and suggested a role in preventing infections, which the study did not test.

This matters because the line between immunity and mood is thinner than it looks. Inflammation can raise anxiety and fatigue, and anxiety can change immune signalling. A peptide that touches both systems is plausible biology. Separately, FDA flagged immunogenicity, the risk that an injected peptide provokes an immune reaction, linked to peptide aggregation and impurities.1017

04 / 11

Selank for anxiety: what the trials found

The best-known trial was published in 2008. Sixty-two people with generalized anxiety disorder or neurasthenia, a diagnosis of chronic fatigue and irritability used in Russian psychiatry, received either Selank or medazepam, a benzodiazepine. Anxiety scores fell similarly in both groups, measured on the Hamilton, Zung and clinical global impression scales.

Selank did something extra. It also had antiasthenic and psychostimulant effects, meaning patients felt less worn out and more alert. Benzodiazepines tend to push the other way, so a calming medicine that leaves people more awake is the kind of profile the developers were hoping for.

A 2014 study compared Selank with phenazepam, a benzodiazepine widely used in Russia, in 60 people with phobic, anxiety and somatoform disorders. The researchers reported a pronounced anxiolytic effect, a mild nootropic effect, better quality of life, and an anxiolytic effect that lasted about a week after the last dose.

These are encouraging results with clear limits. The trials were small, published in a Russian journal, and run by teams that include Selank’s developers. The abstracts describe comparisons with active drugs rather than placebo, which makes it harder to separate a real effect from expectation and the natural ups and downs of anxiety.111

05 / 11

Selank and benzodiazepines: the side-effect finding

Selank is usually pitched as a replacement for benzodiazepines. Its most interesting study tested something else. In 2015, the Moscow group gave 30 people with anxiety disorders phenazepam alone and 40 people phenazepam plus Selank, then tracked both relief and side effects.

The combination group improved sooner on the HDRS rating scale. The bigger finding was on the cost side. With Selank added, people had fewer of phenazepam’s typical side effects, including trouble with attention and memory, fatigue, sedation, oversleeping, sexual problems, emotional flatness and dizziness on standing. The benefit held during treatment and after the tranquilizer was stopped, and quality of life rose.

Animal and lab work hint at why this might happen. In stressed rats, diazepam plus Selank brought anxiety measures back to their pre-stress level, the best result under stress. Yet in receptor assays, the joint action of Selank and some benzodiazepines was not simply additive, and Selank could even block diazepam’s modulating effect. The two seem to share a neighborhood on the receptor without stacking on top of each other.

One hypothesis is that Selank fine-tunes the GABA receptor rather than pushing it harder, which would fit a calmer, clearer combination. That is unproven, and it cuts both ways. A peptide that changes how a benzodiazepine behaves is, by definition, a drug interaction. The finding is a reason to involve a prescriber, never a reason to combine them on your own.1273

In 2015, the Moscow group gave 30 people with anxiety disorders phenazepam alone and 40 people phenazepam plus Selank, then tracked both relief and side effects.

06 / 11

Selank, memory and the anxious brain

Anxiety and memory share hardware. The amygdala flags threats, and the hippocampus and prefrontal cortex decide what to remember and how to respond. Selank research has looked at both ends. In rats, a nasal dose changed BDNF expression in the hippocampus, the growth factor at the center of Semax research too.

A 2019 rat study tested Selank in a harsher setting. Rats drank alcohol as their only fluid for 30 weeks. During withdrawal, untreated animals developed memory and attention problems, while Selank prevented them. It also prevented the alcohol-driven rise in BDNF in the hippocampus and frontal cortex, a reminder that what Selank does to BDNF depends on the setting, and that no study here sets a BDNF target for people.

In people, the best look comes from a 2020 imaging study of 52 healthy volunteers. After Selank, Semax or placebo, scans showed changes in the connection between the right amygdala and the right temporal cortex, with effects specific to each peptide. That shows measurable changes in an anxiety-related circuit soon after a dose, without directly tracking the peptide itself. It does not yet show a change in how anyone feels or thinks.658

Know your baseline before any peptide

120+ lab tests at Quest Diagnostics, every result reviewed by a licensed clinician. Most results in 3–5 business days. A baseline today gives your clinician something to compare against if you start Selank later.

Start with 120+ lab tests · $99Get early access to peptide care

Full refund before your blood draw · No membership

07 / 11

What we actually know in people

The human record fits in a short list. A 62-person trial against medazepam, a 60-person trial against phenazepam, a 70-person trial of phenazepam with and without Selank, a study of immune cytokines in anxious patients, and an imaging study in 52 healthy volunteers. That is more than most peptides in this guide.

All of it comes from Russian research centers, and most of it from teams that include the peptide’s developers. Outside Russia, a 2021 review in the Journal of Clinical Pharmacology grouped Selank with phenibut as poorly studied Russian drugs with GABA-related mechanisms that are sold to US consumers as supplements, and urged proper evaluation of abuse potential before public access.

Put plainly, the clinical signal is consistent but local. None of the studies cited here is a large placebo-controlled efficacy trial or an independent replication outside Russia. The fair summary is a promising Russian anxiety peptide that the rest of the world has not yet tested.1111210813

08 / 11

Selank side effects and safety

The developers’ reports describe Selank as free of the side effects typical of most anxiolytics, and the 2015 study suggests it may even soften a benzodiazepine’s side effects. The 2014 and 2015 trials did assess tolerability, the 2015 one with a standard side-effect scale, but trials of 60 to 70 people cannot rule out uncommon problems, and the studies cited here do not establish long-term safety.

FDA’s April 2026 compounding safety page lists selank acetate. It states that FDA lacks important information on safety in humans and notes a risk of immunogenicity from peptide aggregation and impurities. That concern fits a peptide built from an immune signal and sold in products of unknown purity.

The 2021 pharmacology review adds a broader warning. Drugs that act on GABA receptors can cause dependence and withdrawal, and combining them with other sedatives has caused serious harm. The review does not show that Selank does this. It does urge proper evaluation of abuse potential before public access, which is exactly the point.

In practice, the people who should talk to a clinician first are anyone taking a benzodiazepine, sleep medicine or other sedative, anyone on psychiatric medicine, people with autoimmune conditions, and anyone pregnant or breastfeeding.2121713

The developers’ reports describe Selank as free of the side effects typical of most anxiolytics, and the 2015 study suggests it may even soften a benzodiazepine’s side effects.

09 / 11

Labs that find what is feeding the alarm

Anxiety has common physical drivers that a blood test can catch. TSH screens the thyroid, because an overactive gland produces a racing heart, restlessness and poor sleep that feel exactly like anxiety. Cortisol is worth checking when a clinician suspects an adrenal problem, though a single reading is not a measure of anxiety.

Red-cell magnesium and vitamin B12 round out the picture. Low magnesium is linked with tension and poor sleep, and low B12 can show up as fog, low mood and nervousness. None of these is a Selank marker, and none is a required gate before standard anxiety care. They are targeted checks a clinician may order when symptoms or history suggest a physical contributor.

This is how Vitals Vault approaches peptide care. A blood panel at Quest Diagnostics comes first, and a licensed clinician reviews your results and history before discussing any option. Selank is not currently a compounding option in the US, which makes finding the treatable cause even more useful.1718

10 / 11

Is Selank FDA approved? Where it stands in 2026

Selank is not FDA-approved for any use. FDA’s compounding safety page lists selank acetate among bulk substances that may present significant safety risks, and it was not among the six peptides covered by FDA’s October 29, 2026 enforcement discretion for 503A pharmacies.

That leaves no standard US prescription route. Products sold online as research chemicals are not intended for people, and a supplement label does not establish identity, purity or safety, which matters more than usual for a peptide FDA has flagged for immunogenicity.171813

11 / 11

What this means for you

Selank is an immune peptide turned anxiety medicine, with a coherent lab story around GABA and enkephalins and a handful of small Russian trials that look encouraging. Its most original finding is that it may make a benzodiazepine easier to live with, and that same finding marks it as a drug interaction to respect.

If anxiety is what brings you here, the better first question is what is feeding the alarm. Sleep, thyroid, blood sugar and a few nutrients are testable today. Once those are answered, the next question for a clinician is whether you need a brake at all, or a quieter engine.1123

Know your baseline before any peptide

120+ lab tests at Quest Diagnostics, every result reviewed by a licensed clinician. Most results in 3–5 business days. A baseline today gives your clinician something to compare against if you start Selank later.

Start with 120+ lab tests · $99Get early access to peptide care

Full refund before your blood draw · No membership

What to expect with Selank

The first step is a clinician’s assessment of what drives your anxiety, with a history and, where they fit, labs such as thyroid or B12. Because Selank is not FDA-approved or covered by the October 2026 policy, the conversation with a US clinician centers on those drivers and on approved options.

On timing, the Russian trials describe calm building over a course of treatment, and one reported that the effect lasted about a week after the last dose. In the 2015 study, relief came sooner when Selank was added to a benzodiazepine. These are small studies, so treat any timeline as a rough guide.111217

Key Selank studies

  • Zozulya et al., 20012

    Lab and patient blood study · People with anxiety and phobic disorders

    Enkephalins broke down faster in generalized anxiety; Selank inhibited the enzymes responsible

    Limits: Mechanism study, not a treatment trial

  • Zozulia et al., 20081

    Comparative clinical trial · 62 people with generalized anxiety or neurasthenia (30 Selank, 32 medazepam)

    Similar anxiety relief to medazepam, plus less fatigue and more alertness

    Limits: No placebo group; developer-linked

  • Uchakina et al., 200810

    Lab and clinical immune study · People with depression, anxiety and neurasthenia; healthy controls

    Suppressed IL-6 gene expression in patient cells only; shifted blood cytokine balance

    Limits: Immune markers, not symptoms

  • Medvedev et al., 201411

    Comparative clinical trial · 60 people with anxiety, phobic and somatoform disorders

    Clear anxiety relief and mild nootropic effect; the anxiety relief lasted about a week after stopping

    Limits: Small; abstract gives few comparison details

  • Medvedev et al., 201512

    Comparative clinical trial · 70 people with anxiety disorders (30 phenazepam alone, 40 phenazepam plus Selank)

    Faster relief and fewer benzodiazepine side effects with Selank added

    Limits: No placebo; developer-linked; small

  • Panikratova et al., 20208

    Placebo-controlled imaging study · 52 healthy volunteers

    Changed amygdala-temporal cortex connectivity after a single dose

    Limits: Brain activity, not symptoms

Key studies on Selank
StudyDesignWhoWhat it foundLimits
Zozulya et al., 20012Lab and patient blood studyPeople with anxiety and phobic disordersEnkephalins broke down faster in generalized anxiety; Selank inhibited the enzymes responsibleMechanism study, not a treatment trial
Zozulia et al., 20081Comparative clinical trial62 people with generalized anxiety or neurasthenia (30 Selank, 32 medazepam)Similar anxiety relief to medazepam, plus less fatigue and more alertnessNo placebo group; developer-linked
Uchakina et al., 200810Lab and clinical immune studyPeople with depression, anxiety and neurasthenia; healthy controlsSuppressed IL-6 gene expression in patient cells only; shifted blood cytokine balanceImmune markers, not symptoms
Medvedev et al., 201411Comparative clinical trial60 people with anxiety, phobic and somatoform disordersClear anxiety relief and mild nootropic effect; the anxiety relief lasted about a week after stoppingSmall; abstract gives few comparison details
Medvedev et al., 201512Comparative clinical trial70 people with anxiety disorders (30 phenazepam alone, 40 phenazepam plus Selank)Faster relief and fewer benzodiazepine side effects with Selank addedNo placebo; developer-linked; small
Panikratova et al., 20208Placebo-controlled imaging study52 healthy volunteersChanged amygdala-temporal cortex connectivity after a single doseBrain activity, not symptoms

Selank myths and evidence

  • Selank is a natural supplement, so it is safe to try

    Selank is a synthetic peptide with GABA-related effects. A 2021 pharmacology review called it poorly studied and criticized its sale as a supplement, and FDA notes a lack of human safety information.1317

  • Selank works exactly like a benzodiazepine

    It acts on the same GABA receptor family, but lab work shows its effect is not simply additive with benzodiazepines, and it also acts on enkephalins, BDNF and immune signals. Patients in a 2008 trial reported less fatigue, which benzodiazepines rarely produce.312

  • Selank has been proven in large trials

    The human trials enrolled 60 to 70 people each, were run in Russia and mostly compared Selank with active drugs. None of the studies cited here is a large placebo-controlled or independent trial.11112

On this page

  1. How an immune peptide became an anxiety medicine
  2. How Selank works: GABA, enkephalins and gene switches
  3. Still an immune peptide at heart
  4. Selank for anxiety: what the trials found
  5. Selank and benzodiazepines: the side-effect finding
  6. Selank, memory and the anxious brain
  7. What we actually know in people
  8. Selank side effects and safety
  9. Labs that find what is feeding the alarm
  10. Is Selank FDA approved? Where it stands in 2026
  11. What this means for you
  12. What to expect
  13. Key studies
  14. Myths and evidence

Know your baseline first

120+ lab tests at Quest, every result reviewed by a licensed clinician. Most results in 3–5 business days.

Start with 120+ lab tests · $99

How is Selank taken?

In the studies reviewed here, Selank was given by injection or into the nose. Because it is not FDA-approved and not covered by the October 2026 policy, there is no standard US prescription form.6817

Selank dosage

There is no FDA-approved dose of Selank for any use. It is registered as a nasal medicine in Russia, and the one human study we found that reports a dose gave it into the nose every day for about two weeks in adults with generalized anxiety disorder; that dose is listed in the table on this page. Most Russian trial abstracts do not state a dose. Your clinician decides whether any use is appropriate and sets the dose.16

Typical Selank dosage

Selank is given into the nose. The only human dose we could confirm comes from a small Russian study in adults with generalized anxiety disorder, reported as a conference abstract; the larger Russian trials do not state a dose in their abstracts. There is no FDA-approved dose, and your clinician decides whether any use is appropriate and sets the dose.

These are reference doses from FDA labels, studies in people and clinical practice reports, shown for education. They are not a recommendation or a prescription. Your dose, form and schedule should be set by a licensed clinician who knows your history and lab results.

Already have a prescribed dose? The peptide dosage calculator turns it into the units to draw on an insulin syringe.

  • Human trial · Into the nose

    2,700 µg a day (900 µg single dose)

    Daily; number of doses a day not stated16

    20 adults aged 24 to 52 with generalized anxiety disorder, followed to day 14; congress abstract

Typical Selank doses in people, by source
SourceFormAmountHow oftenNotes
Human trial16Into the nose2,700 µg a day (900 µg single dose)Daily; number of doses a day not stated20 adults aged 24 to 52 with generalized anxiety disorder, followed to day 14; congress abstract

Is Selank right for you?

A clinician makes the call. These are the questions they will ask first.

It may suit

  • Adults who want a clinician to check for physical contributors to anxiety, with labs where they fit
  • People curious about non-sedating options who accept that the evidence is early

Talk to a clinician first if you are

  • Taking a benzodiazepine, sleep medicine or other sedative (Selank changed how diazepam worked in rat and lab studies)
  • Taking antidepressants or other psychiatric medicine
  • Living with an autoimmune condition (tuftsin is an immune peptide)
  • Pregnant or breastfeeding
  • Living with kidney or liver disease

Vitals Vault peptide care starts with a blood panel and a licensed clinician, and ends with a retest.

Get early access to peptide care

Anxiety lives in the same network as sleep, blood sugar and thyroid

Anxiety can have physical drivers that a blood test can catch, such as an overactive thyroid, low magnesium or low B12. A peptide that acts on the brain’s calming system is unlikely to fix a problem that starts elsewhere.

So the sensible first step is to find out what is feeding the alarm, then decide whether anything more is needed.35

What else moves the same system

  1. 01Sleep firstRegular sleep is one of the most reliable non-drug anxiety levers.
  2. 02Rule out the mimicsAn overactive thyroid, low B12 and iron problems can all look like anxiety and are simple to test.
  3. 03Steady mealsLong gaps between meals can bring energy crashes that feel like anxiety.
  4. 04Move dailyRegular aerobic exercise is one of the better-supported ways to lower baseline anxiety.

Labs to check with Selank

A blood test before you start and a retest after shows what actually changed for you. It is how Vitals Vault approaches every treatment.

  1. TestA baseline panel at Quest Diagnostics.
  2. DecideA licensed clinician reviews your history and results.
  3. RetestThe same markers again, side by side.
Start with 120+ lab tests · $99
  • TSH (thyroid)An overactive thyroid causes anxiety, a racing heart and poor sleep, and is easy to rule out.
  • CortisolYour main stress hormone. A clinician may check it when an adrenal problem is suspected; one reading is not a measure of anxiety.
  • Magnesium (RBC)Low magnesium is linked to tension and poor sleep.
  • Vitamin B12Low B12 can look like anxiety and brain fog.

Is Selank FDA approved?

No. Selank is not FDA-approved for any use. FDA’s compounding safety page lists selank acetate among bulk substances that may present significant safety risks, noting immunogenicity concerns for some routes and a lack of human safety information. It is not one of the six peptides covered by FDA’s October 2026 enforcement discretion.1718

Selank timeline

  1. 1999

    A review marks 30 years since Victor Najjar discovered tuftsin, the immune peptide Selank is built on.15

  2. 2001

    Russian team reports that Selank inhibits the enzymes that break down enkephalins, a proposed route for its anxiolytic effect.2

  3. 2008

    Trial in 62 people with generalized anxiety or neurasthenia compares Selank with medazepam; a separate study reports immune cytokine changes.110

  4. 2014

    Trial in 60 people with anxiety disorders compares Selank with phenazepam.11

  5. 2015

    Adding Selank to phenazepam reduces the benzodiazepine’s side effects in 70 people.12

  6. 2018

    Binding studies show Selank acts as a positive allosteric modulator at GABA receptors.3

  7. 2020

    Brain-imaging study in 52 healthy volunteers compares Selank, Semax and placebo.8

  8. April 2026

    FDA’s compounding safety page lists selank acetate and notes the lack of human safety information.17

  9. October 29, 2026

    FDA grants enforcement discretion for six peptides. Selank is not one of them.18

A mixed Pacific Islander and white woman, 56, strong build, wavy grey-blonde hair, blue eyes pauses on a cliff path

Selank questions

What is Selank used for?

Selank was developed in Russia and is studied for anxiety, neurasthenia, stress and memory. It is not FDA-approved to treat any condition, and nearly all human studies come from Russian groups.

What are the benefits of Selank?

In a Russian trial of 62 people, Selank had anxiolytic effects similar to the benzodiazepine medazepam, with less fatigue. In another study, adding it to phenazepam reduced that drug’s side effects. In rats, it protected memory and changed BDNF levels.

How does Selank work?

Receptor-binding work suggests Selank modulates GABA receptors. It also slowed the breakdown of enkephalins in blood samples and changed BDNF and immune signals in rat and cell studies. The exact route in people is not settled.

What is the difference between Selank and Semax?

Both are Russian peptides with a Pro-Gly-Pro tail. Selank comes from tuftsin and is studied for anxiety. Semax comes from ACTH and is studied for stroke, memory and focus. FDA’s October 2026 policy covers Semax but not Selank.

Can Selank be taken with benzodiazepines?

Only under a clinician’s care. A 2015 Russian study found adding Selank to phenazepam reduced side effects, but lab work shows Selank changes how benzodiazepines act at their receptor, so the combination is an interaction to manage, never a DIY experiment.

What are the side effects of Selank?

Russian researchers report it lacks the side effects typical of most anxiolytics, and two trials assessed tolerability, but the studies were small and short. The studies cited here do not establish long-term safety, and FDA notes a lack of human safety information.

What is the Selank dosage?

There is no FDA-approved dose. In a small Russian study of adults with generalized anxiety disorder, Selank was given into the nose every day for about two weeks, and that dose is listed in the dosage table on this page. Most Russian trials do not report a dose in their abstracts. Your clinician decides whether any use is appropriate and sets the dose.

Is Selank FDA approved?

No. Selank is not FDA-approved for any use and is not one of the six peptides covered by FDA’s October 2026 compounding policy. FDA’s compounding page lists it among substances that may present significant safety risks.

Is Selank legal in the US?

It is not an approved drug, and it is not covered by FDA’s October 2026 enforcement discretion. Vials sold online as "research use only" are not made for people and are not regulated as medicine.

Can I get Selank through Vitals Vault?

Vitals Vault is opening clinician-led peptide care that starts with a blood test. Join the peptides waitlist to hear first. A licensed clinician reviews your history and labs and decides whether Selank is right for you.

Peptides, prescribed and measured

Vitals Vault is opening peptide care that starts with your blood work, is prescribed by licensed US clinicians and ends with a retest. Join the waitlist to hear first.

  • Prescription only
  • Licensed US clinicians
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Keep reading

Full Peptide Guide
  • SemaxA seven-amino-acid nasal peptide used in Russia for stroke, studied for memory, focus and BDNF.
  • EpitalonA four-amino-acid pineal peptide studied for telomeres, melatonin and healthy aging.
  • DSIPA nine-amino-acid peptide first isolated in 1977 and named for sleep, with thin human evidence.
  • FDA peptide update 2026What FDA’s October 2026 decision on six peptides means for you.
  • CerebrolysinA mixture of peptides and amino acids from pig brain, used in some countries for stroke and dementia, with weak evidence in Cochrane reviews.

Sources

  1. 1. Zozulia AA, et al. Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia. Zh Nevrol Psikhiatr Im S S Korsakova. 2008 (opens in a new tab)
  2. 2. Zozulya AA, et al. The inhibitory effect of Selank on enkephalin-degrading enzymes as a possible mechanism of its anxiolytic activity. Bull Exp Biol Med. 2001 (opens in a new tab)
  3. 3. Vyunova TV, et al. Peptide-based anxiolytics: the molecular aspects of heptapeptide Selank biological activity. Protein Pept Lett. 2018 (opens in a new tab)
  4. 4. Volkova A, et al. Selank administration affects the expression of some genes involved in GABAergic neurotransmission. Front Pharmacol. 2016 (opens in a new tab)
  5. 5. Kolik LG, et al. Selank, peptide analogue of tuftsin, protects against ethanol-induced memory impairment by regulating of BDNF content in the hippocampus and prefrontal cortex in rats. Bull Exp Biol Med. 2019 (opens in a new tab)
  6. 6. Inozemtseva LS, et al. Intranasal administration of the peptide Selank regulates BDNF expression in the rat hippocampus in vivo. Dokl Biol Sci. 2008 (opens in a new tab)
  7. 7. Kasian A, et al. Peptide Selank enhances the effect of diazepam in reducing anxiety in unpredictable chronic mild stress conditions in rats. Behav Neurol. 2017 (opens in a new tab)
  8. 8. Panikratova YR, et al. Functional connectomic approach to studying Selank and Semax effects. Dokl Biol Sci. 2020 (opens in a new tab)
  9. 9. Siebert A, et al. Tuftsin: properties and analogs. Curr Med Chem. 2017 (opens in a new tab)
  10. 10. Uchakina ON, et al. Immunomodulatory effects of selank in patients with anxiety-asthenic disorders. Zh Nevrol Psikhiatr Im S S Korsakova. 2008 (opens in a new tab)
  11. 11. Medvedev VE, et al. A comparison of the anxiolytic effect and tolerability of selank and phenazepam in the treatment of anxiety disorders. Zh Nevrol Psikhiatr Im S S Korsakova. 2014 (opens in a new tab)
  12. 12. Medvedev VE, et al. Optimization of the treatment of anxiety disorders with selank. Zh Nevrol Psikhiatr Im S S Korsakova. 2015 (opens in a new tab)
  13. 13. Doyno CR, et al. Sedative-hypnotic agents that impact gamma-aminobutyric acid receptors: focus on flunitrazepam, gamma-hydroxybutyric acid, phenibut, and selank. J Clin Pharmacol. 2021 (opens in a new tab)
  14. 14. Dolotov OV, et al. Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus. Brain Res. 2006 (opens in a new tab)
  15. 15. Siemion IZ, et al. Tuftsin: on the 30-year anniversary of Victor Najjar’s discovery. Peptides. 1999 (opens in a new tab)
  16. 16. Syunyakov T, et al. Rapid and slow response during treatment of generalized anxiety disorder with peptide anxiolytic Selank (congress abstract P-1114). Eur Psychiatry. 2012 (opens in a new tab)
  17. 17. FDA. Certain bulk drug substances for use in compounding that may present significant safety risks (current as of April 22, 2026) (opens in a new tab)
  18. 18. NCPA. FDA grants enforcement discretion for compounding six peptides. October 29, 2026 (opens in a new tab)

Written by the Vitals Vault editorial team, medically reviewed by Robert Lufkin, MD, and updated October 29, 2026. This is general education, not medical advice. None of these peptides is FDA-approved to diagnose, treat, cure or prevent any disease, and compounded medicines are not FDA-reviewed for safety, effectiveness or quality. Talk to a licensed clinician before starting any treatment.

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