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Selank Treats Anxiety by Protecting the Body's Natural Anxiety-Relieving Enkephalins

RPEP-007082001Zozulya, A A; Kost, N V; Yu Sokolov, O; Gabaeva, M V; Grivennikov, I A; Andreeva, L N; Zolotarev, Y A; Ivanov, S V; Andryushchenko, A V; Myasoedov, N F; Smulevich, A B
Clinical TrialModerate evidence
The takeaway

Anxiety disorder patients had faster enkephalin degradation in blood, and the peptide drug Selank worked as an anxiolytic partly by inhibiting enkephalin-degrading enzymes, preserving the body's natural anxiety relief.

Natural defense protected

Selank's anxiolytic effect correlates with protecting enkephalins from premature degradation — preserving the body's own anti-anxiety system

What the researchers found

Anxiety patients showed accelerated enkephalin degradation, and Selank's anxiolytic effect correlated with inhibition of enkephalin-degrading enzymes, preserving endogenous opioid-mediated anxiety relief.

Why it matters

Most anxiolytics work through GABA (benzodiazepines) or serotonin (SSRIs). Selank's opioid-preserving mechanism represents a fundamentally different approach — boosting natural anxiety control rather than artificially suppressing anxiety circuits.

How the study worked

Clinical study examining enkephalin half-life and enkephalinase activity in blood from patients with various anxiety and phobic disorders (DSM-4 criteria). Selank treatment effects on both anxiety symptoms and enkephalin metabolism measured.

What this study cannot tell us

Clinical study with limited methodological details in abstract. The correlation between enzyme inhibition and symptom improvement doesn't prove causation. Blood enkephalin dynamics may not reflect brain levels.

How to read the evidence

Moderate evidence from a clinical study with biochemical correlation between enzyme inhibition and symptom improvement in diagnosed anxiety patients.

When this study was published

Published in 2001. Selank has been approved for clinical use in Russia as an anxiolytic peptide drug.

The bigger picture

Anxiety may involve not just excessive fear circuits but also deficient natural calming systems. Protecting the body's own anti-anxiety opioid peptides is a paradigm-shifting treatment concept.

Questions still open

  • Could dedicated enkephalinase inhibitors treat anxiety?
  • Is enkephalin deficiency a biomarker for anxiety disorders?
  • Does Selank's mechanism avoid benzodiazepine-type dependence?

Common questions

What is Selank?
Selank is a synthetic peptide based on tuftsin (an immune peptide) that has been developed and approved in Russia as an anxiolytic and nootropic drug. It works differently from Xanax or SSRIs by protecting the body's own anti-anxiety opioid peptides.
Is this better than benzodiazepines?
The mechanism is different: instead of directly sedating anxiety circuits (like benzodiazepines), Selank strengthens the body's natural calming system. This may avoid the dependence and withdrawal problems of benzodiazepines, though head-to-head comparisons are limited.

Read the original research

The inhibitory effect of Selank on enkephalin-degrading enzymes as a possible mechanism of its anxiolytic activity.

Bulletin of experimental biology and medicine, 131(4), 315-7

View on PubMed ↗

Citation

Zozulya, A A; Kost, N V; Yu Sokolov, O; Gabaeva, M V; Grivennikov, I A; Andreeva, L N; Zolotarev, Y A; Ivanov, S V; Andryushchenko, A V; Myasoedov, N F; Smulevich, A B. (2001). The inhibitory effect of Selank on enkephalin-degrading enzymes as a possible mechanism of its anxiolytic activity.. Bulletin of experimental biology and medicine, 131(4), 315-7.