What Is Selank and Why Reconstitution Technique Matters
Selank is a heptapeptide research compound derived from the immunomodulatory tetrapeptide tuftsin, presented in lyophilised (freeze-dried) powder form that must be reconstituted with bacteriostatic water before subcutaneous use. Unlike pre-mixed liquid peptides, lyophilised Selank retains significantly greater shelf-life stability — studies on lyophilised peptide formulations consistently show degradation rates well below 2 % per year at −20 °C compared to aqueous solutions, which can lose measurable potency within weeks at the same temperature. Proper reconstitution directly determines the concentration and, therefore, the accuracy of every dose drawn.
Reconstitution: Diluent, Volume and Technique
Bacteriostatic water (BW) is the recommended diluent for Selank 10 mg vials; sterile water for injection is an acceptable alternative only when the full vial will be used within 24 hours. Adding 2 mL of BW to a 10 mg vial yields a working concentration of 5 mg/mL (5,000 mcg/mL), which simplifies insulin-syringe measurement — a standard 100-unit (1 mL) insulin syringe then delivers 500 mcg per 10 units drawn. The diluent should be injected slowly down the inner wall of the vial, never directly onto the lyophilised cake, and the vial should be swirled gently rather than shaken to avoid peptide chain degradation.
Storage: Temperature, Light and Post-Reconstitution Windows
Unreconstituted Selank vials should be stored at 2–8 °C (standard refrigerator) for short-term use or at −20 °C for periods exceeding three months. Once reconstituted, the solution must be kept at 2–8 °C and used within 28 days; exposure to light accelerates oxidative degradation, so amber-coloured vials or foil wrapping are recommended during refrigeration. Master Pharma's lyophilisation process produces a stable cake structure that reconstitutes uniformly, a quality parameter verified batch-specifically under GMP-aligned production conditions before each lot is released.
Subcutaneous Injection: Site Selection and Execution
Subcutaneous administration places Selank solution into the adipose tissue layer just beneath the skin, typically at the abdomen (2 inches from the navel), outer thigh, or lateral deltoid — sites with adequate subcutaneous fat depth for reliable absorption. A 29–31 gauge, 0.5-inch (12.7 mm) insulin needle inserted at a 45° angle delivers the peptide into the correct tissue plane; rotating injection sites each session reduces local lipodystrophy risk. Selank's reported plasma half-life is approximately one to two minutes in circulating blood following peripheral administration, with central nervous system effects mediated via GABA-A receptor modulation persisting considerably beyond the peptide's direct circulatory window.