Bacteriostatic water for peptides (10 mL and 30 mL)

In brief: ALTA PEPTIDES supplies Bacteriostatic Water (0.9% benzyl alcohol, sterile) as 10 mL and 30 mL vials for from £5.99, supplied as manufactured, with no certificate of analysis, held in UK stock and dispatched the same working day before 1pm. Supplied for laboratory research only, not for human consumption.

New to Bacteriostatic Water? Read our guide, Bacteriostatic water explained: what it is, how it differs from sterile water, and where to get it in the UK, for what it is, what the research covers and how it is handled.

What is bacteriostatic water?

Sterile, non-pyrogenic water containing 0.9% benzyl alcohol as a bacteriostatic preservative, supplied in a sealed multi-dose vial. The preservative inhibits bacterial growth in the vial after the stopper has been punctured, which is what makes it the standard diluent for reconstituting lyophilised peptides that will be drawn from more than once. Plain sterile water (no preservative) is for single-use reconstitution only.

Which size?

The 10 mL vial reconstitutes several peptide vials at typical volumes of 1 to 3 mL each. The 30 mL vial suits laboratories running many reconstitutions or larger diluent volumes. Both are sealed, USP-grade, and should be discarded 28 days after the first puncture regardless of how much remains.

Bacteriostatic water 10ml suits most researchers; bacteriostatic water 30ml suits higher throughput. Both are in UK stock.

Using it with our peptides

Swab both stoppers, draw the required volume, and add it slowly down the inside wall of the peptide vial rather than onto the powder; swirl, do not shake. The calculator converts vial amount and diluent volume into concentration and syringe units. Storage of reconstituted peptides is given on each product page.

Bacteriostatic vs sterile water

Bacteriostatic water: preserved, multi-dose, 28-day in-use life. Sterile water for injection: unpreserved, single use, discard the remainder. Never use tap, bottled or boiled water: not sterile, wrong pH, and it will degrade the peptide.

Bac water: the same thing

Bac water, BAC water and bacteriostatic water are one product: sterile water with 0.9% benzyl alcohol. Searches for bac water UK usually want exactly this, a multi-dose vial that can be drawn from repeatedly for reconstituting research peptides. Our bacteriostatic water guide covers how it differs from plain sterile water.

Bacteriostatic Water price (UK)

Prices include VAT. Shipping is £4.95 by Royal Mail Tracked 48, free on orders over £75, and sealed items can be returned within 14 days. Ships from UK stock with the lot certificate for the vial you receive.

Quality and testing

Every lot of Bacteriostatic Water is released with its certificate of analysis published on our certificates page against the lot number on the vial label. The certificate for the current lot is pending publication, and ALTA's own independent third-party test of the lot is pending; both are added to the certificates page as they arrive. Specification: Sterile, USP grade, supplied as sealed multi-dose vial.

Lot traceability

Every Bacteriostatic Water vial carries a printed lot number and expiry. The same lot number appears on the certificate of analysis for that lot on our certificates page, which names who issued it (the manufacturer's QC laboratory for a batch certificate, or the outside laboratory for a third-party report) so it can be checked directly. ALTA's own independent test of each lot is published on the same row as it arrives. If the number on your vial does not match a certificate on our site, contact support before using it. Certificates are kept online for the life of the product plus two years.

Related products

Insulin Syringes 1 mL, Alcohol Prep Swabs, BPC-157, and everything else in Water & Accessories or the full range. Reconstitution supplies: bacteriostatic water, insulin syringes and alcohol swabs.

Related reading in the Journal

• Bacteriostatic water explained: what it is, how it differs from sterile water, and where to get it in the UKThe diluent every peptide laboratory keeps on the shelf: what the benzyl alcohol does, why the 28-day rule exists, when plain sterile water is the better choice, and what to look for when buying it in the UK.
• Does filtering peptides remove bacteria? Sterile filtration explainedPassing a peptide solution through a 0.22 micron syringe filter removes bacteria and fungi; it does not remove viruses, endotoxin or chemical contaminants, and it can remove some of the peptide. What sterile filtration is for and where it fits with bacteriostatic water and lot testing.
• How to reconstitute peptides: a laboratory guideWhich diluent to use, how to work out the volume for a target concentration, and the handling steps that keep a lyophilised peptide intact.
• How to store peptides, and how long lyophilised peptides last at room temperatureTemperatures, light, moisture, freeze-thaw cycles and aliquoting: what actually determines how long a peptide stays within specification.
• What is PT-141? Bremelanotide, the brain-acting peptide behind Vyleesi, and what the trials showPT-141, or bremelanotide, is a seven-amino-acid ring-shaped peptide that acts on melanocortin receptors in the brain rather than on blood flow. It was approved in the US in 2019 as Vyleesi for low sexual desire in premenopausal women, after two trials found small but real improvements; nausea was common. It is not licensed in the UK. What it is, what the trials found and where it stands.

Handling and buying guides: How to read a peptide certificate of analysis, Are peptides legal in the UK? Research peptides and the law explained.

Handling and storage

Room temperature, discard 28 days after first puncture. Keep sealed until use. Allow the vial to reach room temperature before opening to avoid condensation on the powder. Reconstitute with bacteriostatic water added slowly down the wall of the vial; do not shake. Our calculator covers the arithmetic.