Who sells bacteriostatic water right now?
Plenty of the peptide vendors we track sell it alongside their peptides, which makes it easy to add to an order you're already placing. The list below pulls from the same live data as our peptide pages: who has it in stock, the bottle size, and the price per mL this week.
- Solyn30 mL · $13.99 $0.47/mL
- Alpha Labs30 mL × 25 · $391.99 $0.52/mL
- Simple Peptide30 mL · $18.00 $0.60/mL
- Reserve Research10 mL · $7.50 $0.75/mL
- Solyn10 mL · $7.99 $0.80/mL
- SP Bio Labs10 mL × 10 · $80.00 $0.80/mL
- Simple Peptide10 mL · $8.00 $0.80/mL
- Solyn30 mL · $24.99 $0.83/mL
- Iron Protocol30 mL · $29.00 $0.97/mL
- Alpha Labs30 mL · $29.99 $1.00/mL
Prices change week to week, so the list updates on its own. If a vendor you like isn't on it, look in their supplies or accessories section, since many shelve bacteriostatic water there rather than with the peptides. You can also browse every vendor we track on our vendor page.
What makes a bottle worth buying?
Two numbers. Bacteriostatic water is sterile water with 0.9% benzyl alcohol added. The benzyl alcohol is a preservative: it doesn't kill bacteria, but it stops them from growing, which is what lets you draw from the same vial over several weeks. The US Pharmacopeia (USP, the body that sets the quality standard) allows a range of 0.72% to 1.08%.
The second number is pH, a measure of how acidic or alkaline the water is. The USP range is 4.0 to 7.0. Most peptides hold up best in mildly acidic water, and water that runs alkaline can break them down faster or turn a mixed vial cloudy.
You can't test either one at home, so look for a bottle labeled USP grade with 0.9% benzyl alcohol stated plainly, from a seller who will share a certificate of analysis (COA) if you ask. If a seller can't tell you the benzyl alcohol content, buy it somewhere else.
Why did Amazon stop selling it?
Independent testing by Peptide Crafters found that 9 of 11 bacteriostatic water products bought on Amazon failed basic USP standards. Most came in too alkaline, and two were short on benzyl alcohol. Amazon pulled the category in early 2026. The cheap listings that disappeared were mostly the ones that failed, so buying from a peptide vendor or a supply specialist isn't a step down. Our news piece has the full results.
Can I use sterile water instead?
For a vial you'll use over days or weeks, no. Plain sterile water has nothing in it to stop bacteria from growing, so once the seal is broken it's meant to be used once and thrown out. Every time a needle goes through the stopper there's a small chance of bringing something in with it, and in sterile water nothing holds that back.
That's the whole job of the benzyl alcohol in bacteriostatic water. It's why a reconstituted peptide vial can sit in your fridge for a few weeks of doses. If you're mixing a vial you'll finish in a single draw, sterile water works, but that's rarely how peptide vials get used.
And never tap water, distilled water from the grocery store, or saline you had on hand for something else. None of those are made to go under the skin.
Bacteriostatic water or sterile water
Bacteriostatic water
0.9%benzyl alcohol
The preservative stops bacteria from growing, which is why one vial can be drawn from over several weeks.
Sterile water
Oncethen throw it out
Nothing in it stops bacteria growing, so once the seal is broken it is meant for a single use.
Which size is the better buy?
Compare price per mL, because bottle prices are misleading. Small 3 mL and 10 mL vials tend to cost more per mL than a 30 mL bottle, and the list above shows how much. If you reconstitute more than one vial a month, the big bottle is the better buy and you'll use it up well within 28 days.
If you mix one vial now and then, a smaller bottle can still make sense. Bacteriostatic water you throw out on day 29 isn't a bargain. Our bac water math guide shows how much a typical vial takes, so you can work out how much you'll actually use.
How do I store it once it arrives?
Unopened, keep it somewhere cool and out of the light, and go by the expiration date. Once you've put a needle through the stopper, keep it in the fridge, write the date on the label, and use it within 28 days. Wipe the stopper with an alcohol swab before every draw. The storage guide covers the rest.
This guide is general information about buying and handling a reconstitution supply, not medical advice.
