Bacteriostatic water (0.9% benzyl alcohol in sterile water)
Bacteriostatic water, often called bac water, is sterile water with 0.9% benzyl alcohol added. It is used as a solvent when lyophilised (freeze-dried) peptides are reconstituted in the laboratory. The difference from ordinary sterile water is the preservative: benzyl alcohol makes the water bacteriostatic, meaning it inhibits bacterial growth, so that an opened vial can be used over time rather than having to be used up in a single operation. This page explains the product's role in batch, COA and laboratory handling, and does not give injection or usage instructions.
Bacteriostatic means inhibiting, not killing. Benzyl alcohol acts as a preservative and can limit microbial growth in multi-dose containers under controlled laboratory conditions, but it does not sterilise a vial that is already contaminated; sterile equipment and clean technique remain essential. The 0.9% concentration is the established standard for multi-dose containers and is the same in both 3 ml and 10 ml vials; the size only determines how many reconstitutions one vial covers.
Technical mechanism
Benzyl alcohol inhibits bacterial growth in reconstituted peptide solutions. Extends the shelf life of multi-dose containers compared with plain sterile water.
What is being researched?
•Laboratory handling of lyophilised research materials
•Batch and COA documentation for excipients
•Sterility, preservative and compatibility in controlled laboratory set-ups
About the evidence: This is an excipient, not a research peptide. This page should be assessed on product quality, sterility, COA and laboratory procedures, not on molecule-specific efficacy studies.
Research profile
Category
Excipient
Reported half-life
N/A
Sources
Documentation coming soon
Laboratory status
Follow the batch COA, the safety data sheet and your internal laboratory SOP. No usage protocols are published.
Research Use Only. Not for human consumption, diagnostics or therapeutic use. This guide summarises published research and laboratory information, not dosing, treatment or instructions for use. Always check information against primary sources, the batch COA and internal laboratory procedures.
