The molecule, in three dimensions
- Heavy atoms
- 53
- Bonds
- 55
- Composition
- C33 N11 O9
- Rings
- 3
- Metal centre
- None
- Chain length
- 7 residues
Every heavy atom is placed from the sequence with ideal bond lengths and angles, so the connectivity is exact. The pose is idealised, an extended chain, and is not a measured conformation. Identity for the lot in stock is confirmed by LC-MS on its certificate.
Molecular data
| Molecular formula | C33H57N11O9 |
|---|---|
| Molecular weight | 751.88 Da |
| Sequence | H-Thr-Lys-Pro-Arg-Pro-Gly-Pro-OH |
| Sequence length | 7 residues |
| CAS / identifier | 129954-34-3 |
| Physical form | Lyophilized powder |
| Available sizes | 10mg, 60mg |
The sequence
Selank is published as a 7-residue sequence. It is set below in reading order, ten residues to a row, numbered from the N-terminus. Every position is a standard L-amino acid.
- T Thr
- K Lys
- P Pro
- R Arg
- P Pro
- G Gly
- P Pro
One-letterTKPRPGP
- Residues
- 7
- Published as
- Three-letter code
- N-terminus
- Free amine (H)
- C-terminus
- Free acid (OH)
How it works
-
GABAergic
GABA-A Receptor Modulation
Research indicates Selank modulates GABAergic neurotransmission, including GABA-A receptor activity and expression of GABAergic system components. This mechanism is associated with the anxiolytic effects observed in preclinical animal models and early clinical studies, without the sedative or dependency concerns seen with classical benzodiazepines.
- Modulates GABA-A receptor subunit expression
- Anxiolytic effects without benzodiazepine-type sedation
- No reported physical dependence in preclinical models
-
Neurotrophin
BDNF & Enkephalin Upregulation
Raised brain-derived neurotrophic factor (BDNF) expression and altered enkephalin metabolism have been measured. BDNF is central to neuroplasticity and synaptic maintenance. Enkephalin stabilisation is one proposed mechanism behind the mood and cognitive endpoints recorded in preclinical studies.
- BDNF expression measured in hippocampal regions
- Stabilizes enkephalin via enkephalinase inhibition
- Modulates serotonin and dopamine turnover
-
Immunomodulatory
Tuftsin-Derived Immune Regulation
Selank is derived from the immunomodulatory tetrapeptide tuftsin (Thr-Lys-Pro-Arg) with a proline-glycine-proline extension that raises stability. Changes in cytokine production including IL-6, IL-1β and TNF-α expression have been measured, which is why it is investigated for both neurological and immunological activity.
- Derived from tuftsin (natural immunomodulator)
- Modulates pro-inflammatory cytokine expression
- Influences interferon alpha/gamma signaling pathways
What the research shows
-
Neuropharmacology
Anxiolytic Mechanisms
Preclinical studies demonstrate anxiolytic effects in elevated plus maze and open field tests, attributed to GABAergic modulation. Selank shows anxiolytic activity comparable to diazepam without sedative side effects in rodent models.
-
Cognitive Research
Memory & Learning
Learning and memory consolidation measures are recorded in animal models of stress-induced cognitive impairment. Raised BDNF and enkephalin stabilisation are proposed as the underlying mechanisms.
-
Immunology
Cytokine & Immune Modulation
Studies report Selank modulates expression of interleukin-6, TNF-α, and interferon signaling pathways, consistent with its tuftsin-derived immunomodulatory origin. Investigated as a model for peptide-based neuroimmunomodulation research.
-
Gene Expression
Transcriptomic Studies
Gene expression studies identify Selank-induced changes in transcription of genes related to serotonin, dopamine metabolism and synaptic plasticity - a molecular pharmacology framework for studying peptide anxiolytics.
Specification
| Chemical Name | Thr-Lys-Pro-Arg-Pro-Gly-Pro (Selank) |
|---|---|
| Sequence | H-Thr-Lys-Pro-Arg-Pro-Gly-Pro-OH |
| Molecular Weight | 751.88 Da |
| Molecular Formula | C33H57N11O9 |
| Form | Lyophilized powder |
| Purity | ≥99% (HPLC verified) |
| Testing | Third-party HPLC, Mass Spec, Endotoxin |
| Storage | -20°C for long-term stability |
| Solubility | Water-soluble |
| COA | Included with every order |
How it's tested
Every lot of Selank released to the catalog carries a third-party certificate of analysis. 4 documented lots are on file for this compound, with reported HPLC purity from 99.09% to 99.75% (mean 99.55%), issued by Accurate Test Labs and Freedom Diagnostics. 3 of 4 certificates record identity as confirmed.
- Documented lots
- 4
- Reported purity
- 99.09% to 99.75%
- Mean purity
- 99.55%
- Issuing labs
- Accurate Test Labs, Freedom Diagnostics
- 2026-10-06 Lot SEL-100226-60Accurate Test Labs 99.09% View certificate
- 2026-09-08 Lot SEL-090226-10Accurate Test Labs 99.75% View certificate
- 2026-07-24 Lot S91YKXAccurate Test Labs 99.607% View certificate
Frequently asked questions
What is Selank and where does it originate?
Selank is a synthetic heptapeptide (7 amino acids) developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It is derived from the immunomodulatory tetrapeptide tuftsin (Thr-Lys-Pro-Arg), which is a natural fragment of IgG immunoglobulin. A Pro-Gly-Pro extension was added to increase the peptide's stability and half-life. Selank is approved in Russia as an anxiolytic drug for generalized anxiety disorder and neurasthenia.
How does Selank work as an anxiolytic?
Selank's anxiolytic endpoints are attributed to several mechanisms. Changes in GABA-A receptor expression and GABAergic neurotransmission have been measured, similar to but distinct from benzodiazepines. Raised BDNF, enkephalin stabilisation via enkephalinase inhibition, and altered serotonin and dopamine metabolism have also been recorded - a multi-target profile.
Is Selank approved by the FDA?
No. Selank is not approved by the FDA or the European Medicines Agency (EMA). A pharmaceutical form is approved in Russia for anxiety and neurasthenic conditions; the research-grade material sold on eonpeptides.com is not that product. Characterisation outside Russia is very limited, and most research originates from Russian institutions. It is sold here for in vitro research use only.
What makes Selank different from benzodiazepines?
Selank acts on GABAergic activity through a different mechanism from benzodiazepines. In preclinical studies, anxiolytic endpoints were recorded without the sedation, motor impairment or physical dependence seen with classical benzodiazepines. In rodent models it behaves as an anxioselective agent, with anxiety-related behaviour scored separately from sedation.
What is the relationship between Selank and the immune system?
Selank is derived from tuftsin, a natural tetrapeptide with well-characterised immunostimulatory activity. Changes in cytokine production (IL-6, TNF-α, interferon signalling) have been measured, and a neuroimmune bridging role is one proposed interpretation. That dual activity is why it appears in neuroimmunomodulation research on links between anxiety, stress and immune function.
How should research-grade Selank be stored?
Lyophilized Selank should be stored at -20°C away from moisture and light. The Pro-Gly-Pro C-terminal extension raises Selank's resistance to proteolytic degradation compared to tuftsin, giving greater stability in biological research conditions.
Cross-references
Other entries in this volume that bear on Selank, with the reason each one is listed.
- Semax cognitive and neuropeptide research Cognitive Function Studies
- DSIP cognitive and neuropeptide research Studied in sleep-architecture, stress-response, and endocrine research
- Pinealon cognitive and neuropeptide research Tripeptide studied in neuronal oxidative-stress models
- Selank / Semax blend carrying this compound Two-peptide blend · lyophilized
For laboratory research use only. Not a drug, supplement, or medical product; not for human or animal use. All findings referenced are from published preclinical/laboratory research.