Overview & mechanism
Bacteriostatic water is sterile water for injection with 0.9% benzyl alcohol added as a bacteriostatic preservative. The preservative allows a reconstituted vial to be safely used over multiple weeks (typically up to 28 days) when refrigerated, versus sterile water which should be used within 24 hours. It is the standard diluent in peptide research for reconstituting lyophilized powder.
Research dose & half-life
- Half-life:
- N/A — solvent
- Research dose:
- Use enough to achieve a workable concentration (typically 1–3 mL per vial). See our reconstitution calculator for exact dilutions.
Safety & side effects
The benzyl alcohol preservative is not appropriate for neonates ("gasp syndrome") and should be avoided in pregnancy at large volumes. Rare hypersensitivity to benzyl alcohol can cause local irritation. Keep the vial refrigerated after opening, wipe the stopper with alcohol before each draw, and discard 28 days after first puncture or sooner if cloudy, discolored, or contaminated. Do not use if the seal is compromised.