Bacteriostatic water: what it is, storage and shelf life

Bacteriostatic water is sterile water containing a small amount of benzyl alcohol (typically 0.9%), which inhibits bacterial growth. That preservative is why it is commonly chosen to reconstitute peptides that will be drawn from over several days or weeks.

Bacteriostatic vs sterile water

• Sterile water: no preservative; intended for single use.
• Bacteriostatic water: contains benzyl alcohol, allowing multiple withdrawals from the same vial over its labelled in-use period.

Storage and shelf life

Lyophilised (powder) peptides are generally most stable refrigerated, and some tolerate freezing. Once reconstituted, most peptides are kept refrigerated and used within a limited window — often a few weeks — because peptides in solution degrade over time. Always follow the specific product's guidance, and check each peptide's storage note in the library.

This is general education, not medical advice. Product handling varies; verify with the manufacturer and a licensed clinician.