What is the difference between bacteriostatic water and sterile water for peptide reconstitution?

Bacteriostatic water contains 0.9% benzyl alcohol as a preservative that inhibits bacterial growth, allowing the solution to be used for up to 28 days after opening when stored properly at 2-8°C. Sterile water contains no preservatives and must be used immediately or discarded after opening, as it cannot prevent contamination once the vial is accessed. For peptides requiring multiple doses over time, bacteriostatic water is the preferred choice due to its extended shelf life and antimicrobial properties.