What is Bacteriostatic Water?
Bacteriostatic water is sterile water containing 0.9% benzyl alcohol as a preservative. Its labelled uses and opened-container period depend on the specific diluent product. The preservative does not make bacteriostatic water compatible with every peptide, ensure sterility after poor handling or establish a 28-day in-use period for a reconstituted peptide. Use only where the exact formulation's instructions support it.
What is Sterile Water?
Sterile water for injection contains no antimicrobial preservative. It may be the supplied or specified diluent for a particular product. Follow its own label and the final formulation's handling instructions rather than applying a blanket immediate-use or multi-dose rule to every peptide.
Which Should You Use for Peptides?
Use the exact diluent identified by the approved product information or validated lot-specific technical documentation. Consider compatibility, intended container, preservative, sterility and documented expiry. A nominal 5 mg or 10 mg vial strength cannot determine the correct diluent or volume. The site's concentration examples are arithmetic demonstrations only.
Storage and Shelf Life Comparison
Store bacteriostatic water and sterile water exactly as stated on the labelled product, and apply the manufacturer's beyond-use or discard instructions after opening. For a reconstituted peptide, the final product's validated instructions control the temperature and discard date. Do not infer peptide stability from the diluent container alone and do not apply a universal 24-hour or 28-day rule across different formulations.