Bacteriostatic Water: The Solvent Behind Every Vial

Every lyophilized peptide in the catalog has one thing in common: it comes back to life with bacteriostatic water. It’s the most unglamorous item we sell, and the one most protocols depend on.

What it is

Bacteriostatic water is USP-grade sterile water with 0.9% benzyl alcohol added as a preservative. The benzyl alcohol is the whole point — it keeps the solution bacteriostatic, meaning bacteria don’t readily grow in it after the vial is punctured.

That’s the difference from plain sterile water: sterile water is sterile until you open it, then it’s just water. Bacteriostatic water stays usable across multiple draws, which is exactly what a 10 mL vial of it is for.

Why reconstitution needs it

Lyophilized peptides are stored dry because they’re stable that way. Reconstitution turns the powder into a measured solution — and the solvent choice matters:

• Bacteriostatic water: standard for multi-dose reconstitution (BPC-157, TB-500, GLP-1 compounds, most peptides).
• Sterile water: used when a protocol specifies preservative-free handling — the reconstituted solution is used within a short window.

Always follow the Certificate of Analysis and the protocol’s own solvent specification. See the reconstitution guide for the full math.

The math side

The reconstitution calculator handles the arithmetic — vial dose ÷ water volume = concentration, then convert to U-100 units. For splitting large volumes like a 500 mg NAD+ reconstitution, the dilution calculator takes over.

Practical notes

Bacteriostatic water stores at room temperature and ships in sterile 10 mL vials — see Bacteriostatic Water for the full spec. Pair it with sterile empty vials and insulin syringes for a complete bench setup.

For laboratory research use only. Not medical advice.