What is bacteriostatic water?
Updated 2026-09-16 · PeptideTech editorial
Bacteriostatic water is water formulated with a preservative that inhibits bacterial growth. The formulation and intended use matter: a research supply and a prescription diluent are different products, even when their names sound similar.
What does it contain?
The prescription label cited below describes sterile water with 0.9% benzyl alcohol (9 mg/mL). Other formulations exist, so check the actual concentration and full label rather than assuming every bottle has the same composition. A preservative does not make a contaminated product sterile.
Bacteriostatic water versus sterile water
Bacteriostatic describes inhibition of bacterial growth; sterile describes a microbiological condition. These words answer different questions. Check whether a particular sterile-water product contains a preservative and whether its manufacturer labels it for single or multiple use. They are not interchangeable solely because both contain water.
How to compare research supplies
Compare the same bottle volume and formulation. Check preservative concentration, intended laboratory use, packaging integrity, manufacturer identity, lot number, expiry and available batch documentation. Include shipping in the total price. A low price per mL does not establish quality or suitability for a research protocol.
Storage and handling
Follow the specific manufacturer’s storage, handling and disposal instructions and your laboratory’s validated procedures. Do not infer a universal opened-bottle shelf life from another brand’s label. This guide does not provide injection, treatment or human-use instructions.
Looking for Genetek bacteriostatic water?
The former storefront guide appeared in searches for Genetek bacteriostatic water. This restored guide is an independent reference, not a Genetek product listing or endorsement. Use the supplier’s current label and lot documentation to establish the identity and suitability of any particular bottle.
Research labels and medical labels
The prescription label linked below is a reference for that labeled product; it does not establish that a research vendor’s bottle has the same specifications. A research-use-only label is not evidence that a product is suitable for administration to people.