Is bacteriostatic water the same as reconstitution solution?

Bacteriostatic water is one type of reconstitution solution, but the two terms are not interchangeable. "Reconstitution solution" covers any sterile liquid used to dissolve a lyophilized powder, including sterile water and saline. Bacteriostatic water is the version with 0.9% benzyl alcohol added as a preservative, and it is the one research peptide guides assume unless they say otherwise.

When a guide or product page says "reconstitution solution," read the vial label to see which liquid it means.

Bacteriostatic water vs other reconstitution solutions

Four liquids come up when people talk about reconstituting a peptide. They differ in two ingredients, a preservative and salt.

The preservative is what matters most for vial handling. Without it, an opened vial has no protection against microbes and should be treated as single-use. Bacteriostatic water vs sterile water covers that comparison, and bacteriostatic water vs saline covers the salt question.

Whichever liquid you pick, concentration is the milligrams of peptide divided by the millilitres added. How to reconstitute a lyophilized peptide walks through the math and the technique.

How long bacteriostatic water lasts once opened

An opened vial of bacteriostatic water has two limits, and the earlier one wins:

• The expiry date printed on the vial.
• The time since the stopper was first punctured. Many pharmacy guidelines set this at 28 days for a multi-use vial unless the manufacturer's label says otherwise.

Write the date of the first puncture on the vial so you don't have to guess. Discard it before either limit if the liquid is cloudy, has particles in it, or the stopper looks damaged.

Once a peptide has been added, a separate clock starts. A reconstituted vial kept cold is generally good for a few weeks, because the preservative slows microbial growth but does not stop the peptide itself from breaking down. How to store research peptides has the details.

Refrigerating and freezing bacteriostatic water

Plain bacteriostatic water, opened or not, should be stored the way its label directs. The benzyl alcohol is what protects an opened vial, so the fridge is not what keeps it usable. A reconstituted peptide vial is different: it goes in the fridge at 2 to 8°C, away from the door shelf where the temperature swings.

Freezing bacteriostatic water gains you nothing. Water expands as it freezes, which can crack a glass vial or loosen the seal around the stopper, and there is no shelf-life reason to take that risk.

The freezer is for the dry powder. If a reconstituted solution has to be kept longer, the storage guide explains how to split it into single-use aliquots before freezing, so no portion is thawed more than once.

Buying bacteriostatic water in Canada

Bacteriostatic water is a laboratory supply at pepuro, sold alongside the peptides it is used to reconstitute. You order it online like any other item in the catalog. There is no account paperwork, only the same research-use confirmation at checkout that applies to every order.

Bacteriostatic water comes in 3, 10, 20 and 30 mL vials. Each is sterile water with 0.9% benzyl alcohol and no salt. The 30 mL vial is Pfizer (Hospira) brand, and the smaller sizes are generic. It is a diluent, not a peptide, so it is not purity tested by HPLC the way a peptide vial is.

Pharmacies set their own policies on what they stock and to whom they sell it, so we can't speak for them. For how research chemicals and their supplies are treated in Canada more broadly, see are research peptides legal in Canada? This page is general information, not legal advice.

Every order ships free from our Calgary, Toronto and Vancouver distribution centers, the same business day your e-Transfer clears, and every peptide vial carries a QR code that opens its own third-party lab report.

For research use only. Not for human or animal consumption.