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3 min readLast reviewed 16 May 2026
Anxiolytic / Mood

Selank

Also known as: TP-7 · Thr-Lys-Pro-Arg-Pro-Gly-Pro

A synthetic heptapeptide analogue of tuftsin developed for anxiolytic and immunomodulatory research, with measurable effects on attention and mood.

Anxiolytic / MoodUK: Research onlyNot for human use
Category
Anxiolytic / Mood
Half-life
Intranasal: minutes; pharmacodynamic effects 24h+
Formula
C₃₃H₅₇N₁₁O₉
Weight
751.87 g/mol
Sequence
Thr-Lys-Pro-Arg-Pro-Gly-Pro

Section 1

Overview

Selank is a synthetic seven-amino-acid peptide built around the tetrapeptide tuftsin (Thr-Lys-Pro-Arg), an endogenous immunomodulator. Tuftsin itself has a vanishingly short half-life; Selank extends the molecule with a proline-glycine-proline tail that confers stability and produces a peptide with measurable anxiolytic and pro-cognitive activity in research models.

Selank was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences as part of the same research programme that produced Semax. The two are commonly studied as complementary tools: Selank is broadly positioned as anxiolytic, while Semax leans cognitive/attentional.

In animal anxiety paradigms, Selank produces effects comparable to classical benzodiazepines without the sedation, motor impairment, dependence liability, or amnestic side effects associated with that drug class — a profile attributed to its action on enkephalin metabolism rather than direct GABA-A binding.

Section 2

Discovery & History

  • Synthesised in the 1990s at the Russian Academy of Sciences as an extended, plasma-stable analogue of tuftsin.
  • Granted clinical approval in the Russian Federation as an anxiolytic; used in human research for generalised anxiety, adjustment disorder, and stress-related symptomatology.
  • Studied internationally as a tool peptide for probing the relationship between enkephalin tone, anxiety, and attention.
  • An N-acetylated analogue (N-Acetyl Selank Amidate) was later developed for extended duration of action.

Section 3

Mechanism of Action

  • 1Inhibition of enkephalinase enzymes, prolonging the half-life of endogenous enkephalins and producing anxiolytic effects without direct opioid receptor agonism.
  • 2Modulation of GABAergic tone indirectly via the enkephalin system; no direct GABA-A binding has been demonstrated.
  • 3Upregulation of BDNF expression in the hippocampus, similar to Semax but generally lower magnitude.
  • 4Influence on monoamine turnover — increased serotonergic and dopaminergic metabolite levels in regions associated with mood and motivation.
  • 5Immunomodulatory effects via the tuftsin pharmacophore — measurable changes in cytokine balance, particularly interleukin profiles, in stressed animals.

Section 4

Researched Benefits

Findings reported in the published preclinical and clinical literature. Effects in research contexts do not constitute claims of therapeutic benefit in humans.

  1. 1Reduction of anxiety-like behaviour in animal models (open-field, elevated plus-maze paradigms).
  2. 2Improved attention and cognitive performance under stress in early human studies.
  3. 3Anti-asthenic effect — reduction of mental fatigue and improvement in subjective wellbeing in published trials.
  4. 4No sedative, amnestic, or motor-impairing effects at studied doses, in contrast to benzodiazepines.
  5. 5Immunomodulation — observed normalisation of cytokine profiles in subjects with stress-related immune dysregulation.
  6. 6Synergistic profile with cognitive peptides such as Semax in stack research.

Section 5

Theoretical Dosing & Protocols

The protocols below summarise dose ranges reported in published research only. They are not recommendations and not a guide for human use.
RouteDosageFrequencyDuration
Intranasal (research)Typically 75–300 μg per session in published protocols2–3 times daily in study protocolsStudies generally run 10–21 days

Note: Cyclical use is more common than continuous administration in published research.

Section 6

Administration Routes

  • Intranasal — the established research route, with the same nose-to-brain rationale as Semax.
  • Parenteral routes used in animal research; oral administration is not viable due to proteolytic degradation.

Section 7

Safety Profile

Commonly reported

  • · Mild nasal irritation
  • · Occasional transient headache or lightheadedness
  • · Subtle changes in arousal level (typically reduced anxiety, not sedation)

Rare / theoretical

  • · Hypersensitivity reactions
  • · Long-term Western safety data is limited
  • · Possible interaction with opioid-modulating medications (theoretical, via enkephalin pathway)

Contraindications

  • · Not authorised for human use outside Russia
  • · Pregnancy and lactation — insufficient data
  • · Concomitant opioid antagonist therapy — theoretical interference with mechanism

Section 8

UK & EU Regulatory Context

United Kingdom

Not licensed as a medicine in the United Kingdom. Available strictly as a research chemical for laboratory use.

European Union

Not approved by the European Medicines Agency. Clinically approved in the Russian Federation.

Section 9

Clinical Studies Summary

Russian psychopharmacology literature2008

Selank in generalised anxiety disorder — controlled trial

Russian clinical trial reporting significant reduction in anxiety scores comparable to a benzodiazepine comparator, without sedation or cognitive impairment.

Peer-reviewed immunology journal2013

Selank effects on cytokine profile in stressed subjects

Normalisation of pro-/anti-inflammatory cytokine balance following a course of intranasal Selank.

Peer-reviewed biochemistry literature2010

Enkephalinase inhibition by Selank — mechanistic study

Demonstration of dose-dependent inhibition of plasma and brain enkephalin-degrading activity, providing a molecular basis for the observed anxiolytic effect.

Section 10

Frequently Asked Questions

Selank achieves anxiolysis indirectly — by raising endogenous enkephalin tone — rather than by directly binding GABA-A receptors. Consequently it does not appear to produce sedation, motor impairment, dependence, or rebound anxiety in the studies published to date. It is not, however, a replacement for licensed treatment.

Section 11

Sourcing for Laboratory Research

Sourcing Selank for laboratory research

Researchers in the United Kingdom and elsewhere typically obtain Selank from specialist research-chemical suppliers. Purity, third-party testing, and supplier transparency are the principal differentiators worth evaluating before placing an order. The two suppliers below are commonly referenced in UK research contexts.

Reminder: research peptides are sold strictly for in vitro and preclinical laboratory purposes. Importation or supply for human consumption is not permitted under UK medicines legislation.

Further reading

Related research summaries

Peptide-based anxiolytics — Selank and the enkephalin system

Why endogenous opioid peptide modulation offers a route to anxiolysis without the sedation, dependence, or cognitive impairment of GABA-A approaches.

Read research summary

Intranasal peptide delivery — why the nose-to-brain route matters

The published case for intranasal administration as the dominant route in nootropic peptide research, and the limits of the nose-to-brain pathway.

Read research summary

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