What is Bacteriostatic Water?
Bacteriostatic water is sterile water for injection with benzyl alcohol added as a preservative. The additive inhibits bacterial growth, so a vial can be punctured several times. It is used to dissolve or dilute medicines for injection.
How well studied is Bacteriostatic Water?
It is an established pharmaceutical excipient of pharmacopoeial quality, not an active substance, so there are no efficacy studies in the usual sense. The preservative does not replace sterile technique.
What side effects and risks does Bacteriostatic Water have?
Not suitable for newborns: benzyl alcohol can cause a life-threatening "gasping syndrome" in them. Given intravenously without a dissolved substance it can destroy red blood cells (haemolysis). Some drugs are incompatible with benzyl alcohol; the manufacturer's instructions for the specific medicine always take precedence. Poor technique with multiple-dose vials carries infection risks.
Is Bacteriostatic Water approved in Germany?
In short: no – only outside the EU. In the USA, bacteriostatic water is an FDA-approved prescription product. In Germany it is, to our knowledge, not a common approved finished medicinal product; preservative-free "water for injection" from pharmacies is the usual option. Imports from unclear sources may be of unverified sterility and quality.
Sources
Note: We deliberately do not list any doses here. For approved medicines, your doctor sets the dose; for unapproved substances there is no reliable information.