How to spot fake bacteriostatic water

You spot fake bacteriostatic water by checking the vial, not the liquid. A genuine vial names its manufacturer, reads sterile water with 0.9% benzyl alcohol, carries a lot number and an expiry date, and arrives with its seal intact. Water looks the same whether it contains the preservative or not, so the label, the packaging and the seller are the only evidence you have. If one of them fails, set the vial aside.

This guide is the inspection checklist. For where to buy it and which vial size to pick, see where to buy bacteriostatic water in Canada.

What fake bacteriostatic water usually is

"Fake" covers more than counterfeits. A vial sold as bacteriostatic water can turn out to be any of these:

• Plain water sold as bacteriostatic water. Without the benzyl alcohol it is sterile water at best, which suits single-use preparation only. Bacteriostatic water vs sterile water explains why that matters once a vial is opened.
• Saline or bacteriostatic sodium chloride sold as bacteriostatic water. The salt changes the solution, and bacteriostatic water vs saline covers why the two aren't swapped.
• A relabeled or refilled vial, usually a generic vial with a printed sticker, no lot number, or a stopper that has been punctured before.
• Expired stock sold as new.
• A vial carrying a known brand name whose label, cap or lot format doesn't match the maker's own packaging.

The bacteriostatic water checklist

Work down the vial from the label to the liquid. Each row is something you can check in your hand before the stopper is ever punctured.

The last row only works in one direction. A cloudy vial is out, but a clear one tells you nothing about the benzyl alcohol, because you can't measure it at the bench. A vial can pass every visual check and still be plain water. That is why the seller carries as much weight as the label.

Checks that come from the seller

Bacteriostatic water is a diluent, not a peptide, so it isn't purity tested by HPLC and there is no per-vial lab report to scan the way there is for a peptide. (For peptides, how to read a peptide lab report explains what that report should show.) With no report, the listing and the seller behind it are the paperwork. Before you order, check that:

• the listing states the formula, sterile water with 0.9% benzyl alcohol, and says there is no salt
• the listing names the manufacturer, or says plainly when a vial is generic
• the vial sizes on the listing match what arrives
• the seller is identifiable and ships from within Canada, so there is someone to contact if a vial fails a check

At pepuro, bacteriostatic water comes in 3, 10, 20 and 30 mL vials. The 30 mL vial is Pfizer (Hospira) brand and the smaller sizes are generic. Every size is sterile water with 0.9% benzyl alcohol and no sodium chloride.

When a vial fails a check

Don't reconstitute with it. A contaminated or mislabeled diluent ruins the peptide you add it to, and the peptide is the expensive part. Adding benzyl alcohol yourself doesn't rescue a questionable vial either, since the preservative slows microbial growth but can't make a contaminated vial sterile again.

A vial that passes still has limits once it's opened. Many pharmacy guidelines set 28 days after the first puncture for a multi-use vial unless the manufacturer's label says otherwise, and the printed expiry date still applies. Is bacteriostatic water the same as reconstitution solution? covers those limits in more detail.

When acetic acid is used instead of bacteriostatic water

Dilute acetic acid is a solvent that some peptide data sheets specify for sequences that dissolve poorly in neutral water. Lowering the pH helps those peptides dissolve. It does a different job from bacteriostatic water and contains none of its benzyl alcohol, so it is not a substitute and shouldn't be sold as one.

In practice:

1. Use acetic acid only when the data sheet or a published handling method for that specific peptide names it.
2. If a peptide normally reconstituted with water won't dissolve, don't switch solvents first. Powder that refuses to dissolve is a signal to check the vial's lab report, as how to reconstitute a lyophilized peptide explains.

All pepuro peptides ship lyophilized and ready to reconstitute with bacteriostatic water. We don't sell acetic acid.

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.