How to reconstitute peptides with bacteriostatic water

Reconstituting lyophilized powders is a simple procedure, but technique matters. Mistakes during reconstitution can damage the compound or contaminate the vial. This guide covers the general technique only — always follow the specific instructions provided by the compound's manufacturer.

Supplies

• Bacteriostatic water vial
• Lyophilized powder vial
• Alcohol swabs
• Insulin syringe, typically 1 mL with a 29–31 gauge needle

Step-by-step

1. Wash hands thoroughly, or wear nitrile gloves.
2. Swab both vial stoppers — the bacteriostatic water and the powdered compound — with alcohol wipes. Let dry for 10 seconds.
3. Draw the desired volume of bacteriostatic water into the syringe. Common volumes are 1 mL or 2 mL depending on the desired concentration. Refer to the compound manufacturer's instructions for the recommended volume.
4. Insert the needle into the powder vial. Inject the water slowly along the inside wall of the vial. Do not spray the water directly onto the lyophilized powder — this can damage the compound.
5. Gently swirl the vial in a circular motion. Do not shake. Shaking can denature the compound and reduce potency.
6. Wait until the powder is fully dissolved. The solution should be clear and colorless, with no visible particles or clumps. This typically takes 1–5 minutes.
7. Once reconstituted, store the vial in the refrigerator at 2–8 °C (36–46 °F).
8. Use a new sterile needle for each subsequent withdrawal.

Common mistakes

• Spraying water directly onto the powder instead of along the vial wall.
• Shaking the vial instead of gently swirling.
• Using sterile water instead of bacteriostatic water for a multi-dose vial. Sterile water has no preservative and increases contamination risk with repeated punctures.
• Storing the reconstituted vial at room temperature instead of refrigerated.
• Reusing needles between withdrawals.