Description
Selank at a glance
Selank is a synthetic seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, described in the literature as an analogue of tuftsin. It is studied mainly in anxiety research: a small clinical comparison with a benzodiazepine, rat gene-expression and behavior work, and enzyme assays. Ellepeptides lists Selank in 5 mg and 10 mg freeze-dried vials only, not as a nasal spray.
- Molecule type: synthetic heptapeptide, TKPRPGP
- Vial sizes: 5 mg and 10 mg
- Listed price: from $30.00 USD
- Form: freeze-dried (lyophilized) powder in a sealed vial; no nasal spray or drops
- Shipping: ships within the US, with free shipping on merchandise over $200 after coupons
- Scope: for laboratory research only
Selank vial sizes and price per mg
| Vial size | Listed price (USD) | Price per mg |
|---|---|---|
| 5 mg | $30.00 | $6.00 |
| 10 mg | $65.00 | $6.50 |
Per milligram, the 5 mg vial is the lower-cost option. Prices are listed in U.S. dollars at the time of writing; choose a size above to see the current price. Bulk or combination savings through the cart or coupons are not promised.
Selank compound profile
| Catalog name | Selank |
|---|---|
| Nominal amount per vial | 5 mg, 10 mg |
| Research reference identity | Synthetic seven-residue peptide |
| Reference sequence | H-Thr-Lys-Pro-Arg-Pro-Gly-Pro-OH (TKPRPGP) |
| Reference molecular formula | C33H57N11O9 |
| Reference molar mass | 751.9 g/mol |
| CAS reference | 129954-34-3 |
| Molecular reference source | PubChem CID 11765600 |
| Intended scope | Laboratory research |
The rows above come from the reference structure in PubChem. They identify the molecule a study would name; they do not characterize a specific lot, its counterions or its water content. Selank is a distinct peptide from Semax even though both end in the same Pro-Gly-Pro sequence.
How Selank works in research
Selank’s mechanism is still described in terms of hypotheses. Three lines of evidence recur. The first is GABA-related signaling: in male rats, Volkova and colleagues measured frontal-cortex genes involved in neurotransmission and found that the changes after Selank partly resembled those after GABA, the brain’s main inhibitory messenger (Volkova et al., 2016). An association between gene-expression patterns is not proof that Selank acts on GABA receptors directly.
The second is the enkephalin system. Enkephalins are natural opioid peptides that serum enzymes break down. In human serum tested in vitro, Selank inhibited these enkephalin-degrading enzymes, with an IC50 of about 20 µM compared with about 10 µM for Semax (Kost et al., 2001). In Zozulia’s clinical comparison, patients started with a shorter serum half-life of leu-enkephalin, which correlated with anxiety and asthenia severity, and this measure rose during Selank treatment (Zozulia et al., 2008).
The third is interaction with benzodiazepine pathways. Building on reports that Selank’s anxiety-reducing effect resembles that of classical benzodiazepines, Kasian’s group tested Selank with diazepam in stressed rats (Kasian et al., 2017).
Key Selank studies
| Year | Study & model | What was measured | Main finding | Source |
|---|---|---|---|---|
| 2001 | Kost et al.; human serum, in vitro | Inhibition of enkephalin-degrading enzymes | Selank inhibited the enzymes (IC50 ≈ 20 µM; Semax ≈ 10 µM) | Bioorg Khim |
| 2008 | Zozulia et al.; randomized comparison, 62 patients with generalized anxiety disorder or neurasthenia | Hamilton, Zung and CGI scales; serum leu-enkephalin half-life | Similar anxiety-scale effects to medazepam; enkephalin measure rose with Selank | PubMed |
| 2016 | Volkova et al.; male rats, frontal cortex | Expression of neurotransmission genes | Changes partly resembled those after GABA | PMC |
| 2017 | Kasian et al.; rats, unpredictable chronic mild stress | Elevated plus maze anxiety indicators | Selank plus diazepam was most effective under chronic stress | Behav Neurol |
| 2020 | Panikratova et al.; 52 healthy adults, Selank, Semax or placebo | Amygdala and prefrontal connectivity (fMRI) | Group differences in right amygdala–temporal cortex connectivity | Dokl Biol Sci |
Zozulia’s trial is the main clinical evidence. Thirty patients received Selank and 32 received medazepam, a benzodiazepine comparator. Both groups showed similar anxiety-reducing effects on psychometric scales, and the authors also described anti-fatigue and mildly stimulating effects with Selank. The study is small, published in Russian and, in the accessible abstract, gives no adverse-event detail (source).
Kasian’s rat study used the elevated plus maze. Without chronic stress, the course of treatment itself increased anxiety indicators, but less so after Selank; under chronic stress, the Selank–diazepam combination returned indicators to pre-stress values (source). Panikratova’s imaging work is the only study here in healthy people, and it measured connectivity rather than anxiety.
Selank research involving women
This is a clear evidence gap. Zozulia’s abstract indexes both male and female participants but gives no counts and no separate results by sex (source). Panikratova’s abstract does not report a sex breakdown either. The gene-expression study used male rats only, and the Kasian abstract does not state animal sex. No Selank study reviewed here analyzed outcomes in women or considered hormonal-cycle timing. Until such data exist, women-specific claims about Selank cannot be made.
Selank vs Semax and other focus peptides
| Compound | Type | Main research focus | Sizes on Ellepeptides |
|---|---|---|---|
| Selank | Heptapeptide; tuftsin analogue (TKPRPGP) | Anxiety-scale comparison, GABA-related gene expression | 5 mg, 10 mg |
| Semax | Heptapeptide; ACTH(4–7) + Pro-Gly-Pro (MEHFPGP) | BDNF signaling, ischemia models, brain-network imaging | 5 mg, 10 mg |
| Selank + Semax Blend | Two peptides in one vial, 10 mg + 10 mg | No study of the combined vial; evidence is per component | 20 mg total |
| DSIP | Nine-residue peptide (WAGGDASGE) | Sleep physiology; weak effects in a small insomnia trial | 15 mg |
Selank and Semax are the classic pair: same length, same Pro-Gly-Pro ending, different parents. Selank research leans toward anxiety measures, while Semax research leans toward BDNF and recovery after ischemia (Dolotov et al., 2006). The Selank + Semax Blend combines 10 mg of each in one vial, but no study of that mixture was identified. DSIP belongs to sleep research, where a 1992 double-blind study in chronic insomnia found only weak objective effects (Bes et al., 1992).
Handling, storage and reconstitution math
Each Selank vial holds a freeze-dried cake or powder. The label sets storage conditions for the sealed vial and for any solution made from it, and it takes priority over general guidance. Basic laboratory care applies: keep vials closed and dry until needed, use clean technique, and mark prepared vials with the solvent and date.
Concentration is mass divided by volume. A 10 mg vial taken up in 4.0 mL gives 2.5 mg/mL; a 5 mg vial in 1.0 mL gives 5 mg/mL. Our peptide calculator does this for any combination, and bacteriostatic water (30 mL) is available for laboratories that use a preserved diluent. Nasal formulations are not supplied.
Ordering Selank in the US
Ellepeptides ships Selank to addresses within the United States. Shipping is free when the merchandise subtotal exceeds $200 after coupon discounts (before taxes and shipping); below that, standard shipping is $15.99 per order. Available payment methods and delivery options are shown at checkout. Current details are in the shipping policy.
Selank FAQ
What is Selank?
Selank is a synthetic peptide of seven amino acids, Thr-Lys-Pro-Arg-Pro-Gly-Pro, described as an analogue of tuftsin. It is studied in anxiety research, including a clinical comparison with medazepam and rat studies of gene expression and behavior. Ellepeptides lists it as freeze-dried powder in 5 mg and 10 mg vials.
Can I buy Selank nasal spray in the US from Ellepeptides?
No. Ellepeptides sells Selank only as freeze-dried powder in sealed 5 mg and 10 mg vials. It does not sell nasal sprays, drops or spray bottles. Clinical studies used their own formulated preparations, which are different materials from a laboratory research vial.
How much does Selank cost?
At the time of writing, Selank is listed at $30.00 USD for 5 mg and $65.00 USD for 10 mg, roughly $6.00 and $6.50 per mg. The size selector shows the current price, and free shipping applies when the merchandise subtotal exceeds $200 after coupons.
Where can I buy Selank in the US?
Selank can be ordered from Ellepeptides on this page and ships to US addresses, with free shipping over $200 after coupons. Related compounds appear in the Focus, Mood & Sleep category and the full research peptides catalog.
What does research show about Selank and anxiety?
In a randomized comparison of 62 patients with generalized anxiety disorder or neurasthenia, Selank and medazepam produced similar effects on anxiety scales. In rats, Selank changed GABA-related gene expression and, combined with diazepam, reduced anxiety indicators under chronic stress. In the sources reviewed, the human evidence comes from one small trial.
Selank vs Semax: which is which?
Selank is a tuftsin analogue studied mainly for anxiety measures; Semax is an ACTH(4–7) analogue studied mainly for BDNF and ischemia models. Both are seven residues and end in Pro-Gly-Pro. In one enzyme assay, Semax was about twice as potent. The Semax page has its own sources.
Has the Selank and Semax stack been studied?
Not as a combination. Panikratova’s imaging study gave Selank, Semax or placebo to separate groups of healthy adults, so it compared the peptides rather than combining them. No study of a combined vial was identified. The Selank + Semax Blend page explains what that means.
What side effects of Selank have been reported in studies?
The accessible abstract of the main clinical trial does not give adverse-event detail, and the other studies reviewed here are animal or in vitro work. That means no reliable side-effect profile can be summarised on this page. Researchers needing safety data should consult the full clinical publications.
Is Selank a benzodiazepine?
No. Selank is a seven-residue peptide, while benzodiazepines such as medazepam and diazepam are small synthetic molecules. Selank has been compared with medazepam in patients and studied alongside diazepam in rats, and some authors suggest overlapping mechanisms, but they are different classes of compound.
What is the half-life of Selank?
A plasma half-life for Selank itself is not established in the sources reviewed for this page. The half-life measured in Zozulia’s trial was for leu-enkephalin in patients’ serum, an indirect marker of enzyme activity, not for Selank. Be cautious with uncited half-life figures.
Selank references
- PubChem (NCBI). Selank, CID 11765600. PubChem
- Kost NV, et al. (2001). Semax and Selank inhibit serum enkephalin-degrading enzymes. Bioorg Khim. PubMed 11443939
- Zozulia AA, et al. (2008). Selank in generalized anxiety disorder and neurasthenia, compared with medazepam. PubMed 18454096
- Volkova A, et al. (2016). Selank and GABA-related gene expression in rat frontal cortex. PMC4757669
- Kasian A, et al. (2017). Selank enhances diazepam in chronic mild stress in rats. Behav Neurol. PMC5322660
- Panikratova YR, et al. (2020). Functional connectomics of Selank and Semax. Dokl Biol Sci. PubMed 32342318
- Dolotov OV, et al. (2006). Semax binding and BDNF in rat basal forebrain. PubMed 16635254
- Bes F, et al. (1992). DSIP in chronic insomnia. PubMed 1299794
Related research materials: Focus, Mood & Sleep peptides, Semax, Selank + Semax Blend, DSIP, Pinealon and our research and sourcing notes. For laboratory research only. Not for human or veterinary use.
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