How should I store Bacteriostatic Water?

Store unopened Bacteriostatic Water at room temperature (15-30°C) away from direct light. Once opened, store at room temperature and use within 28 days. Do not freeze.

What is the difference between Bacteriostatic Water and sterile water?

Bacteriostatic Water contains 0.9% benzyl alcohol, which prevents bacterial growth and allows for multiple uses from the same vial. Sterile water for injection does not contain a preservative and must be discarded after a single use.

How much Bacteriostatic Water do I need per vial?

The amount varies depending on the peptide and desired concentration. Typically, 1-2 mL of Bacteriostatic Water is used per peptide vial. Always refer to the specific peptide product instructions for recommended reconstitution volumes.

Bacteriostatic Water - USP-Grade, Injection-Ready

Name: Bacteriostatic Water
Brand: PeptidesDirect
SKU: PD-BACTERIOSTATICWATER-10ML
Availability: InStock

0.9% benzyl alcohol

Sterile water plus 9 mg/mL benzyl alcohol, the USP-monograph concentration that suppresses microbial growth between withdrawals.

Multi-puncture vial, 28 days

The bacteriostatic preservative keeps the vial usable for up to 28 days after the first needle puncture under proper storage.

USP-grade sterility

Manufactured to USP Bacteriostatic Water for Injection specifications: sterile, non-pyrogenic, pH 4.5 to 7.0.

For lyophilized peptide reconstitution

The standard solvent in published peptide protocols. Dissolves freeze-dried research peptides cleanly without altering their structure.

Cold-chain shipped

Dispatched from EU stock with insulated packaging so the vial arrives intact and ready for laboratory use.

Research areas

ReconstitutionUSP standardLyophilized peptidesMulti-dose vial

What is bacteriostatic water

Bacteriostatic water is not a peptide. It is a solvent: sterile water with 0.9% benzyl alcohol added as a preservative. The benzyl alcohol does not kill bacteria outright, but it blocks them from multiplying, which is exactly what a multi-dose vial needs.

The key difference vs sterile water for injection: sterile water is single-use. Once the seal is broken, the vial must be discarded. Bacteriostatic water can be punctured repeatedly and reused for up to 28 days, because the preservative keeps the contents stable between withdrawals. That makes it the practical choice for laboratories working with lyophilized peptides, where each vial is reconstituted and then sampled in small fractions over several weeks.

How the preservative works

Benzyl alcohol is lipophilic. At 0.9% it embeds into bacterial cell membranes and disrupts membrane-bound proteins, halting cell division without killing existing organisms. This is why it is called bacteriostatic rather than bactericidal. The 0.9% concentration is the USP-monograph minimum that holds the 28-day window. Lower concentrations lose protection faster; higher concentrations risk cytotoxicity in cell-culture applications.

How to use

Used as a solvent for lyophilized peptide reconstitution in research workflows. The standard procedure is to draw the chosen volume into a syringe, inject it slowly down the side of the peptide vial, and let the powder dissolve without shaking. The reconstituted peptide is then stored according to its own protocol, while the bacteriostatic water vial can be returned to refrigeration for the next withdrawal.

Often studied alongside

Most lyophilized research peptides are reconstituted with bacteriostatic water as the default solvent in published protocols.

Healing-research peptide reconstituted with bacteriostatic water

BPC-157regeneration

Gastric pentadecapeptide (15 amino acids) known for exceptional tissue repair properties. Promotes wound healing, angiogenesis, and cytoprotection across tendons, muscles, gut, and nerves. Over 30 years of preclinical research.

Copper-peptide reconstituted with bacteriostatic water

GHK-Culongevity

Naturally occurring copper tripeptide complex for skin regeneration and anti-aging research. Stimulates collagen synthesis, accelerates wound healing, and modulates 4000+ genes. Plasma levels decline with age, making it a key target in longevity research.

Multi-peptide blend reconstituted with bacteriostatic water

KLOWregeneration

4-in-1 anti-aging peptide blend: GHK-Cu 50mg + BPC-157 10mg + TB-500 10mg + KPV 10mg. Targets collagen synthesis, tissue regeneration, skin repair, and anti-inflammatory pathways.

Documentation

Material specification

Composition

Sterile water + 0.9% (9 mg/mL) benzyl alcohol

Standard

USP Bacteriostatic Water for Injection

Form

Solution, multi-dose vial

4.5 to 7.0 (USP <791>)

Storage (sealed)

Controlled room temperature, light-protected

Storage (after first puncture)

2 to 8 °C, use within 28 days

CoA

Batch-specific, on request

Lab Report (COA)

Batch NumberBlue

Testing LabJanoshik

Test Date2 Mar 2026

Download COA

Reference standards

No direct PubMed studies are required for bacteriostatic water itself. The relevant references are the USP monograph for Bacteriostatic Water for Injection and the FDA monograph for benzyl alcohol as a preservative. Both define the 0.9% concentration, the pH range of 4.5 to 7.0, and the 28-day post-puncture window used here.

Research use only

This material is sold strictly for in-vitro research and laboratory use. Not intended for human or animal consumption, medical, cosmetic, or household applications. Suitable only for professional laboratory environments.

Bacteriostatic Water