BAC Water
Also known as: bacteriostatic water · bacteriostatic water for injection · BWFI
Sterile water containing 0.9% benzyl alcohol, used to reconstitute lyophilized peptides for multi-dose vial use.
Bacteriostatic water is the standard reconstitution diluent for multi-dose peptide vials. The benzyl alcohol preservative inhibits bacterial growth, allowing the vial to be accessed multiple times over weeks of refrigerated storage without contamination. Sterile saline lacks preservative and is intended for single-use; using saline in a multi-dose peptide vial is a documented contamination path.
BAC water is sold by research supply houses and some pharmacies. It's typically packaged in 30mL multi-dose vials and stored at room temperature. A single BAC vial reconstitutes many peptide vials — cost is trivial compared to the peptide itself.
Related Terms
Reconstitution
The process of dissolving a lyophilized peptide powder in bacteriostatic water or saline to produce an injectable solution.
Vial Shelf Life
The duration a peptide remains stable and potent in its current physical state (lyophilized or reconstituted).
Concentration (mcg/mL)
The amount of peptide mass per unit volume of reconstituted solution, typically expressed as micrograms (mcg) or milligrams (mg) per milliliter.
Drawing Dose
The technique of extracting a measured dose of reconstituted peptide from the vial into an insulin syringe.
Look up any peptide term inside DoseCraft Pro
The glossary is just the start. Inside DoseCraft you get 90+ compound deep-dives, a PK-aware protocol engine, interaction checker, and vendor trust scores — every term surfaced in protocol-design context, not a separate page.
Start Free Trial