Bacteriostatic Water
Sterile water for injection preserved with 0.9% benzyl alcohol. The standard diluent for reconstituting lyophilized research peptides — it allows multi-dose use of a single vial without microbial proliferation.
- Composition
- Water for injection + 0.9% benzyl alcohol
- Sterility
- Sterile · Bacteriostatic
- Vial Size
- 10 / 30 mL multi-dose
- Use
- Reconstitution of lyophilized peptides
- pH
- ~ 5.7 (range 4.5–7.0)
- Form
- Clear, colorless solution
Overview
Bacteriostatic water is a pharmacopoeia-grade sterile water preserved with 0.9% benzyl alcohol. The preservative inhibits bacterial growth, allowing the same vial to be punctured multiple times for sequential reconstitutions without compromising sterility — the property that distinguishes it from sterile water for injection (SWFI), which is a single-use diluent.
Across this catalog, bacteriostatic water is the recommended reconstitution medium for every lyophilized peptide. The standardized 20 mg/mL working concentration used as cross-compound reference assumes use of bac water unless otherwise indicated.
How It Works — The Role of Benzyl Alcohol
Benzyl alcohol disrupts microbial cell membranes at the 0.9% concentration used in pharmacopoeial bacteriostatic water. It is bacteriostatic — it stops growth — rather than bactericidal.
Multi-Dose Use
Allows up to 28 days of multi-puncture vial use without microbial proliferation between draws.
Peptide Compatibility
Compatible with virtually all lyophilized research peptides; does not denature peptide backbones at the 0.9% concentration.
Isotonicity
Bac water itself is hypotonic; final tonicity of the reconstituted solution depends on the peptide salt form.
Limitations
Not appropriate for neonatal research due to benzyl-alcohol exposure thresholds — sterile water for injection is the alternative diluent in those contexts.
Reconstitution Reference Across the Catalog
The table summarizes how each compound in the Peptisynlab catalog reconstitutes when paired with bacteriostatic water at the standardized 20 mg/mL working concentration.
| Compound | Vial | Bac water for 20 mg/mL | 1 mg in IU (insulin syringe) |
|---|---|---|---|
| Retatrutide | 40 mg | 2 mL | 5 IU |
| Tirzepatide | 20 mg | 1 mL | 5 IU |
| BPC-157 + TB-500 | 20 mg | 1 mL | 5 IU (blended) |
| SS-31 | 10 mg | 0.5 mL | 5 IU |
| 5-Amino-1MQ | 5 mg | 0.25 mL | 5 IU |
| Tesamorelin | 5 mg | 0.25 mL | 5 IU |
| Ipamorelin | 10 mg | 0.5 mL | 5 IU |
| GHK-Cu | 100 mg | 5 mL | 5 IU |
Reconstitution Procedure
- Sanitize: wipe both vial stoppers (peptide and bac water) with 70% isopropyl alcohol.
- Draw diluent: with a sterile syringe, draw the calculated volume of bac water from the multi-dose vial.
- Inject slowly: introduce the bac water gently down the inner wall of the lyophilized peptide vial — do not aim the stream directly at the powder.
- Dissolve: swirl the vial slowly to dissolve the lyophilized cake. Do not shake aggressively; foaming and shear can degrade peptides.
- Inspect: the solution should appear clear and colorless (GHK-Cu is the exception — it is blue). Do not use solutions with particulates or precipitates.
- Store: place the reconstituted vial at 2 – 8 °C, protected from light. Label with the reconstitution date.
Storage & Stability
- Sealed vial: store at 15 – 25 °C, protected from light. Do not freeze.
- After first puncture: use within 28 days. Discard sooner if any cloudiness, particulates or color change is observed.
- Sterility: always swab the stopper before each draw; never re-introduce a used needle into the vial.
- Compatibility: compatible with all lyophilized peptides in this catalog.
