Retailer guide · checked 8 October 2026
Bac water at Walmart: price, prescription and what to avoid
Walmart is not a reliable place to buy bac water. Bacteriostatic water for injection is labelled "Rx only", so in store it is a Walmart Pharmacy item that you should expect to need a prescription for, with a cash price of roughly $24–$35 for a 30 mL vial. Searching walmart.com for "bacteriostatic water" also returns humidifier treatments that share the name but are a different product.
Bac water (bacteriostatic water) is sterile water with 0.9% benzyl alcohol (9 mg/mL) as a preservative. This guide covers the Walmart Pharmacy price, the prescription question, the walmart.com naming trap, and how buying online from Direct Bac Water compares.
What does bac water cost at Walmart?
Walmart does not publish a shelf price for bacteriostatic water for injection, because it is filled at the pharmacy counter. Price-comparison sites put the average US retail cash price of a 30 mL vial at $23.76 (GoodRx) and $28.79 (Rx.com), and published price guides quote up to about $35. Expect to pay roughly $24–$35 for a 30 mL vial at Walmart; the exact price depends on the store and ZIP code, so confirm it with the pharmacy.
| Source | 30 mL vial, retail cash price |
|---|---|
| GoodRx average retail price | $23.76 |
| Rx.com retail price | $28.79 |
| Published price guides | Up to about $35 |
Retail cash prices without a discount, checked 8 October 2026.
"Bacteriostatic water treatment" is not bac water
Walmart sells humidifier additives such as "Bacteriostatic Water Treatment" in 32 fl oz bottles, and walmart.com listings for them come up in searches for bacteriostatic water. These are tank treatments for evaporative humidifiers, sold in large bottles. They are not bacteriostatic water for injection and must never be used in its place. Real bac water comes in a small sealed vial labelled with its volume in mL and "0.9% benzyl alcohol".
Do you need a prescription for bac water at Walmart Pharmacy?
Expect to. The FDA label for Hospira bacteriostatic water for injection is marked "Rx only", and pharmacies fill Rx-only products against a prescription. The label also warns "NOT FOR USE IN NEONATES" because of the benzyl alcohol. Stock varies by store, so call the pharmacy first.
Walmart vs Direct Bac Water
| Walmart Pharmacy | Direct Bac Water | |
|---|---|---|
| Where | Pharmacy counter, in store | Online, shipped from US stock |
| Prescription | Expected (product is labelled Rx only) | Not asked at checkout; sold for laboratory research and the reconstitution of legal, physician-prescribed medications only |
| 30 mL vial | about $24–$35 cash price | $18.95, or $14.00 a vial in a 10-pack |
| Sizes | What the pharmacy stocks or orders | 3 mL, 10 mL, 30 mL and Hospira 30 mL |
| How fast | Same day if in stock; otherwise ordered in | Dispatched the same day before 1 pm ET (Mon–Fri); UPS Next Day Air available |
Buying bac water online from Direct Bac Water instead
Direct Bac Water sells US-made bacteriostatic water in sealed 3 mL, 10 mL and 30 mL vials and Hospira 30 mL, from $6.50 a vial. Orders placed before 1 pm Eastern Time, Monday to Friday, leave the same business day by UPS or USPS; standard delivery takes 2–5 business days and is free on orders over $200.
Bac water at Walmart: questions
Does Walmart sell bac water?
Walmart Pharmacy can dispense bacteriostatic water for injection, but it is not a shelf item. It is labelled "Rx only", so expect to need a prescription, and stock varies by store.
How much is bac water at Walmart?
Expect a cash price of roughly $24 to $35 for a 30 mL vial. GoodRx puts the average US retail price at $23.76 and Rx.com at $28.79 (checked 8 October 2026); the exact price depends on the store.
Is "bacteriostatic water treatment" at Walmart the same as bac water?
No. Bacteriostatic water treatment is a humidifier tank additive sold in large bottles. Bacteriostatic water for injection is a different product: sterile water with 0.9% benzyl alcohol in a small sealed vial.
Can you buy bac water at Walmart without a prescription?
Expect to be asked for one. The product is labelled "Rx only", and dispensing without a prescription is up to the pharmacist.
Where else can I buy bac water if Walmart does not have it?
Direct Bac Water sells bacteriostatic water online in 3 mL, 10 mL and 30 mL vials and Hospira 30 mL, from $6.50 a vial, dispatched the same business day for orders placed before 1 pm ET on a weekday.
Sources
- U.S. National Library of Medicine, DailyMed: Bacteriostatic Water for Injection, USP (Hospira, Inc.), package label "Rx only", "NOT FOR USE IN NEONATES". Checked 8 October 2026.
- GoodRx: average retail price of bacteriostatic water, $23.76. Checked 8 October 2026.
- Rx.com: retail price of bacteriostatic water, $28.79. Checked 8 October 2026.
- Published pharmacy price guides quoting up to about $35 for a 30 mL vial without a discount, 2026.
- Google's US results for "bacteriostatic water walmart", showing walmart.com listings for humidifier water treatments. Checked 8 October 2026.
Pharmacy prices and stock change; this page is re-checked every month. Next review: 15 November 2026.