Selank

Description

Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. Its design starts from tuftsin, an endogenous immunomodulatory tetrapeptide (Thr-Lys-Pro-Arg) produced by enzymatic cleavage of immunoglobulin G, and adds a C-terminal Pro-Gly-Pro extension that protects the molecule from rapid enzymatic degradation. This lineage gives Selank an unusual dual research profile: a behavioral, anxiety-related axis inherited from central tuftsin activity, and an immunological axis inherited from tuftsin's role in phagocyte regulation.

The most extensively investigated mechanism in Selank research is its interaction with GABAergic neurotransmission. In electrophysiological and binding studies, Selank has been reported to modulate the sensitivity of GABA-A receptors and to potentiate GABA-mediated inhibitory currents, without acting as a direct receptor agonist. In rodent behavioral batteries — elevated plus maze, open field, and stress-induced paradigms — Selank administration has been associated with reduced anxiety-like behavior, and Russian comparative studies frequently benchmarked it against reference anxiolytics while noting the absence of sedative or muscle-relaxant effects at the studied doses.

A second research axis concerns neurotrophins and neuromodulation. Selank administration in rodents has been associated with increased BDNF expression in the hippocampus, and with inhibition of enkephalin-degrading enzymes, which raises circulating enkephalin levels. Both mechanisms are studied as possible contributors to the peptide's behavioral profile, situating Selank in the same neurotrophic research space as its sibling peptide Semax, with which it shares the stabilizing Pro-Gly-Pro extension.

The third axis is neuro-immune crosstalk. Owing to its tuftsin backbone, Selank has been studied for effects on cytokine balance — including IL-6 and the Th1/Th2 ratio — and on the expression of genes involved in immune signaling. This combination of behavioral and immunological endpoints makes Selank a frequently chosen tool compound for research into how stress and immune function interact at the molecular level.

Selank is supplied as a white lyophilized powder at 10mg per vial, exceeding 98% purity by HPLC analysis. The compact heptapeptide structure is comparatively robust for storage and handling, making it a practical reference material for laboratory work.

EU Shipping: Ships from Spain to all 27 EU countries. Free shipping on orders over €50. No customs delays — intra-EU shipment. Tracked courier.

Reconstitution Protocol

Selank 10mg is supplied as a sterile lyophilized powder for reconstitution with bacteriostatic water. Standard laboratory protocols are summarized below — researchers should validate against their own internal SOPs.

• Recommended diluent: Bacteriostatic Water (BAC water) with 0.9% benzyl alcohol preservative.
• Standard dilution: Add 2 ml of BAC water to the 10mg vial → final concentration 5 mg/ml (5,000 mcg/ml).
• Alternative dilution: Add 5 ml of BAC water → final concentration 2 mg/ml (2,000 mcg/ml) — preferred for protocols requiring smaller working volumes.
• Technique: Dispense the diluent slowly along the inner wall of the vial. Do not aim directly at the powder bed. Swirl the vial gently for 30-60 seconds until fully dissolved. Never shake vigorously. The heptapeptide dissolves readily — full dissolution typically occurs within 1-2 minutes.
• Expected appearance: Clear, colorless, particulate-free solution.
• Typical draw volumes: At 5 mg/ml, researchers typically draw 5-20 μl per experimental aliquot.
• Post-reconstitution stability: Store at 2-8°C protected from light. Use within 30 days.

Stability & Half-Life Data

• Plasma half-life: Very short — on the order of minutes in rodent pharmacokinetic studies. The Pro-Gly-Pro extension slows but does not eliminate enzymatic cleavage.
• Biological activity duration: Despite the short plasma half-life, downstream effects on GABAergic sensitivity, BDNF expression, and cytokine balance persist substantially longer (hours to days) — consistent with Selank acting as a signaling trigger for longer-lived transcriptional changes.
• Lyophilized stability: Up to 24 months at -20°C in a sealed vial protected from light and moisture. Up to 4 weeks at 2-8°C without measurable purity loss.
• Reconstituted stability: 30 days at 2-8°C when reconstituted with bacteriostatic water.
• Thermal stability: The lyophilized form tolerates short transport excursions up to 40°C. The reconstituted peptide should remain refrigerated.
• Freeze-thaw: Avoid repeated freeze-thaw cycles of reconstituted solution. Aliquot before freezing if long-term storage is required.
• Light sensitivity: Moderate. Store reconstituted solution in amber vials or wrapped in foil. Avoid sustained direct UV light.

Composition

• Peptide: Selank
• Sequence: Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP)
• Molecular Formula: C33H57N11O9
• Molecular Weight: 751.87 g/mol
• Purity: >98% (HPLC)
• Appearance: White lyophilized powder
• Quantity: 10mg per vial

Storage

• Store lyophilized peptide at -20C for long-term storage (up to 24 months).
• For short-term storage (up to 4 weeks), refrigerate at 2-8C.
• After reconstitution, store at 2-8C and use within 30 days.
• Avoid repeated freeze-thaw cycles.
• Protect from light and moisture at all times.

Certificate of Analysis

Every batch of Selank sold by Pepspan undergoes rigorous third-party testing. Our Certificate of Analysis (COA) includes HPLC purity analysis, mass spectrometry confirmation, amino acid analysis, endotoxin testing, and sterility verification. COA documentation is available upon request for any batch number. All testing is performed by independent European laboratories to ensure the highest standards of accuracy and reliability.

Current Batch: Pending first shipment

Every batch of Selank sold by Pepspan is independently tested by Janoshik Analytical (Prague, Czech Republic). HPLC purity analysis, mass spectrometry, and amino acid sequencing are performed for each shipment. Reports are batch-specific — not generic.

View All Purity Reports →

Research Disclaimer

This product is intended for laboratory research use only. It is not a drug, food, cosmetic, or dietary supplement. Selank is not approved for human or veterinary use by any regulatory agency in the EU or US. It must not be administered to humans or animals outside of approved clinical trials. By purchasing this product, you confirm that you are a qualified researcher and that this product will be used exclusively for legitimate scientific research purposes. Pepspan assumes no liability for any misuse of this product. All handling must comply with local regulations and institutional safety protocols.

Frequently Asked Questions

What is Selank?

Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It combines the endogenous immune tetrapeptide tuftsin (Thr-Lys-Pro-Arg) with a C-terminal Pro-Gly-Pro extension that increases enzymatic stability. Selank is investigated primarily for anxiolytic mechanisms, GABAergic modulation, and neuro-immune crosstalk research.

How is Selank reconstituted?

Selank 10mg is typically reconstituted with 2 ml of bacteriostatic water, yielding a 5 mg/ml (5,000 mcg/ml) working solution. Dispense the diluent slowly along the inner wall of the vial — never directly onto the powder. Swirl gently for 30-60 seconds until fully dissolved. Do not shake. The solution should be clear and colorless.

What research areas cite Selank in the literature?

Published research on Selank spans anxiolytic endpoints in rodent behavioral models (elevated plus maze, open field), modulation of GABA-A receptor sensitivity, BDNF expression in the hippocampus, inhibition of enkephalin-degrading enzymes, and immune markers such as IL-6 and Th1/Th2 cytokine balance — a legacy of its tuftsin backbone. Researchers should consult the primary literature for the concentrations and models reported in each study.

How long does Selank last after reconstitution?

Reconstituted Selank stored at 2-8°C should be used within 30 days. The small heptapeptide is relatively robust, but protecting from light and avoiding freeze-thaw cycles of the working solution are recommended.

Can I buy Selank in Europe?

Yes. Pepspan ships Selank 10mg lyophilized vials across all 27 EU countries from Spain. Each batch is independently tested by Janoshik Analytical (Prague) for HPLC purity, mass spectrometry, and amino acid analysis. COA included. Research Use Only. Orders ship from Europe — no customs delays, intra-EU shipment.

Do I need a prescription for Selank?

No. Selank is sold strictly as a research reference material for laboratory and in vitro use. It is not approved as a pharmaceutical or supplement in the EU/US.

How does Selank compare to Semax?

Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro, ~752 Da) is derived from the immune tetrapeptide tuftsin and is studied mainly for anxiolytic endpoints via GABAergic modulation. Semax (Met-Glu-His-Phe-Pro-Gly-Pro, ~814 Da) is derived from ACTH(4-7) and is studied mainly for neuroprotective and cognitive endpoints via BDNF/NGF expression. They share the stabilizing Pro-Gly-Pro extension and are often studied as complementary tools in neuropeptide research.

Is Selank tested by Janoshik?

Yes. Every batch of Pepspan Selank is independently tested by Janoshik Analytical (Prague). The Certificate of Analysis covers HPLC purity (>98%), mass spectrometry confirmation, amino acid analysis, endotoxin testing, and sterility. COA is batch-specific and available on request.

Further Research Resources

Additional research articles, comparison guides, and laboratory protocols related to this peptide:

• How to reconstitute research peptides
• How to store research peptides
• How to verify a Certificate of Analysis