Bacteriostatic Water for Peptides
What it is, why it matters, and where to get it.
What Is Bacteriostatic Water?
Bacteriostatic water (BAC water) is sterile water for injection containing 0.9% benzyl alcohol as a preservative. The benzyl alcohol inhibits bacterial growth, making the vial safe for multiple draws over time when handled under proper sterile conditions.
It is the standard diluent used in the research community for reconstituting lyophilized peptides including BPC-157, TB-500, retatrutide, semaglutide, and others.
Why Not Regular Sterile Water?
Plain sterile water for injection contains no preservative. Once the rubber stopper is punctured, repeated needle entries introduce contamination risk with no preservative to inhibit bacterial growth. For single-draw use only.
Bacteriostatic water's 0.9% benzyl alcohol preservative allows multi-dose use when proper sterile technique is followed. For any research protocol requiring multiple draws from a reconstituted vial, bacteriostatic water is the appropriate choice.
What to Look For
- 0.9% benzyl alcohol concentration — verify on the label
- USP grade — pharmaceutical standard
- 30 mL multi-dose vial — sufficient for most research protocols
- Third-party tested supplier — COA available
Sourcing
Recommended Source
PSPeptides carries USP-grade bacteriostatic water, third-party tested. Ships domestically. Use code BANANAS10 for 10% off.
Get BAC Water →Affiliate link — The Protocol Kit earns a commission at no extra cost to you.
Once you have your BAC water, use the free calculator to determine exactly how much to add to your vial.
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