Bacteriostatic Water is 0.9% benzyl alcohol in sterile water for injection — the standard multi-dose-stable reconstitution vehicle for lyophilized research peptides.
Product definition
What is Bacteriostatic Water?
Bacteriostatic Water is 0.9% benzyl alcohol in sterile water for injection — the standard multi-dose-stable reconstitution vehicle for lyophilized research peptides.
Bacteriostatic Water for injection (BWFI) contains 0.9% w/v benzyl alcohol in water for injection. Benzyl alcohol is a bacteriostatic agent — it inhibits bacterial growth without acting as a sterilant. The USP formulation meets the requirements for water for injection plus the benzyl alcohol preservative, packaged in multi-dose vials with rubber stoppers that reseal after each needle puncture.
In research peptide reconstitution, BWFI is the standard vehicle because: (1) it permits multi-draw use across a study protocol without contamination risk; (2) benzyl alcohol is compatible with the pH range of most peptide solutions; (3) it is commercially available in standard research-grade vials with documented sterility testing. For single-use reconstitution or acute use, sterile water for injection (without benzyl alcohol) is an alternative, but BWFI is the default for any protocol spanning multiple research sessions.
Research context
How is Bacteriostatic Water described in the research literature?
Bacteriostatic water uses 0.9% benzyl alcohol as a bacteriostatic preservative — inhibiting microbial replication without sterilizing the solution. This property allows the vial to remain sterile across multiple punctures, making it appropriate for multi-dose peptide reconstitution protocols where a single lyophilized vial is used over days or weeks.
Compound profile
Key facts about Bacteriostatic Water
- Composition
- 0.9% benzyl alcohol in sterile water for injection
- Preservative
- Benzyl alcohol 9 mg/mL
- pH
- Approximately 5.0–7.0 (USP specification)
- Standard
- USP formulation, multi-dose vial
- Available volumes
- 10 mL and 30 mL vials
- Use
- Reconstitution vehicle for lyophilized research peptides
- Storage
- Room temperature (15–30°C), protect from light
Research areas
What research areas is Bacteriostatic Water associated with?
- 0.9% benzyl alcohol preservative enables multi-dose use from a single vial — eliminates single-use waste in multi-day protocols
- Standard reconstitution vehicle for lyophilized research peptides across all compound classes
- Multi-dose stable — maintains sterility across multiple needle punctures throughout protocol duration
- Available in 10 mL and 30 mL vials for single-compound and multi-compound research workflows
- Compatible with standard research peptide pH ranges — no formulation interference
- Reduces preparation complexity in multi-peptide protocols requiring separate reconstitution events
Research audience
Who researches Bacteriostatic Water?
Bacteriostatic water is required by any researcher working with lyophilized research peptides. It is the reconstitution vehicle for all peptide classes including GLP-1 analogs, GHRPs, GHRH analogs, repair peptides, and melanocortin compounds. Any lab using Peptific's lyophilized compounds needs bacteriostatic water as a supporting reagent.
Preclinical research overview
What does the preclinical literature say about Bacteriostatic Water?
Bacteriostatic water is a USP-defined pharmaceutical formulation rather than a research compound — its characterization is regulatory rather than experimental. The 0.9% benzyl alcohol concentration is the established preservative level that inhibits bacterial growth across the range of storage temperatures and use durations typical of multi-dose pharmaceutical vials.
In research peptide applications, the reconstitution vehicle can affect peptide stability, aggregation, and bioactivity. Bacteriostatic water's neutral pH, low ionic strength, and benzyl alcohol preservative profile are compatible with the reconstitution requirements of most peptide classes. For peptides with specific pH sensitivity (e.g., those prone to aggregation at neutral pH), alternative reconstitution vehicles such as dilute acetic acid or phosphate buffer may be used — but BWFI is the default for the majority of research peptide protocols.
The 10 mL vial is appropriate for single-compound use across a typical research protocol window. The 30 mL vial serves laboratories running multiple concurrent compound protocols or higher-throughput research designs where separate reconstitution events are frequent.
Common questions
Frequently asked about Bacteriostatic Water
Why use bacteriostatic water instead of sterile water?
Sterile water without preservative is single-use by convention — once a vial is punctured, subsequent draws carry increasing contamination risk. Bacteriostatic water's benzyl alcohol preservative maintains the solution's sterility across multiple entry points, which is required for any research protocol where the same reconstituted peptide vial will be drawn from over multiple sessions or days. For single-dose reconstitution, sterile water is acceptable; for multi-dose research protocols, bacteriostatic water is the appropriate choice.
Is benzyl alcohol compatible with all research peptides?
Benzyl alcohol (0.9%) is compatible with the majority of research peptides at typical reconstitution concentrations. Exceptions exist for certain formulations sensitive to preservatives at high peptide concentrations, or where benzyl alcohol's slight lipophilicity interacts with hydrophobic peptide sequences. In practice, for the peptide classes carried by Peptific (GLP-1 analogs, GHRPs, GHRH analogs, repair peptides, melanocortins), bacteriostatic water is the standard recommended reconstitution vehicle.
How should reconstituted peptide vials be stored after using bacteriostatic water?
Reconstituted peptide solutions should be stored at 2–8°C (refrigerated, not frozen). The bacteriostatic water handles contamination prevention; temperature handles peptide stability. Most reconstituted peptides are stable for 14–30 days at refrigerator temperature with bacteriostatic water reconstitution — refer to the individual compound's specified stability window. Minimize freeze-thaw cycles of reconstituted material.
Research Use Only
Sold for laboratory and research purposes only. Not approved for, nor intended for, human or veterinary consumption, diagnostic use, or therapeutic application. These products have not been evaluated by the Food and Drug Administration. Keep out of reach of children. For use by qualified researchers only.
Nothing on this page constitutes medical advice, a treatment recommendation, or a clinical protocol. Consult a qualified healthcare provider before making any health or treatment decisions.
By accessing this product page you confirm that you are a qualified researcher aged 18 or older and that you will use this product solely for lawful laboratory research purposes. View Research Use Policy