Bacteriostatic Water — Complete Research Guide

Bacteriostatic water is sterile water for injection containing 0.9% benzyl alcohol as a preservative. It is the standard reconstitution solution for lyophilized (freeze-dried) research peptides and the only diluent that allows a vial to be accessed multiple times safely over weeks. The benzyl alcohol inhibits bacterial replication, maintaining sterility through repeated needle penetrations — a property sterile water (which contains no preservative) cannot offer.

Why Bacteriostatic Water Over Alternatives

Plain sterile water becomes contaminated after the first use and must be discarded. Normal saline can alter peptide pH and stability. Bacteriostatic water's pH is adjusted for compatibility with most research peptides, its benzyl alcohol concentration is clinically validated at the 0.9% threshold, and it maintains potency of reconstituted peptides for up to 60 days when refrigerated. It also provides mild local anesthetic action from the benzyl alcohol — a clinically documented secondary property.

Required for All Peptides

Every lyophilized research peptide — BPC-157, TB-500, GHK-Cu, MT-2, Retatrutide, HGH, Selank, KLOW — requires reconstitution before use. Bacteriostatic water is the recommended diluent for virtually all of them. Always use bacteriostatic water for reconstitution unless specifically instructed otherwise for a particular compound.