Bacteriostatic (BAC) Water 10ml

BAC water (bacteriostatic water) is sterile water that has been processed to remove all microorganisms and then supplemented with 0.9% benzyl alcohol (9 mg/mL) as a bacteriostatic preservative agent. The term “bacteriostatic” means that the preservative inhibits bacterial growth rather than killing bacteria outright (which would be “bactericidal”). This distinction is important: Benzyl alcohol at a 0.9% concentration prevents new microbial contamination from multiplying each time the vial septum is punctured with a needle, maintaining the solution’s sterility across multiple access events over its 28-day use window.

In peptide reconstitution, BAC water serves as the universal diluent to convert lyophilized (also referred to as lyophilized) peptide powder into an injectable solution. When a researcher adds BAC water to a vial of lyophilized peptide, the water dissolves the powder, and the benzyl alcohol preservative protects the resulting solution from contamination during the days or weeks it takes to use the vial’s contents across multiple research doses.

BAC water is manufactured to United States Pharmacopeia (USP) standards, which specify requirements for sterility, endotoxin levels, pH range (4.5-7.0), particulate matter limits, and benzyl alcohol concentration. Healius BAC water meets these USP specifications and is supplied in sealed, tamper-evident 10ml glass vials with rubber stoppered closures designed for multi-dose access with standard insulin syringes.

BAC water does not require a prescription and is not a controlled substance. It is widely available as a pharmaceutical-grade product used in compounding, reconstitution, and dilution of medications and research compounds. Healius supplies BAC water as a convenience product for researchers who need a reliable, verified-quality diluent alongside their peptide orders.

The reconstitution process is the same for virtually all lyophilized research peptides, with only the volume of BAC water added varying between products and desired concentrations.

Step 1: Remove the flip-off caps from both the BAC water vial and the peptide vial to expose the rubber stoppers. Wipe both stoppers with an alcohol swab, then allow them to air-dry for 10-15 seconds. Step 2: Using a sterile syringe (insulin syringe for volumes under 1 mL, or a larger syringe for higher volumes), draw the desired volume of BAC water from the BAC water vial. Step 3: Insert the needle into the peptide vial at a slight angle, with the tip touching the inside of the glass wall. Step 4: Slowly depress the plunger to direct the stream of BAC water down the inside wall of the peptide vial. Do not spray directly onto the lyophilized powder cake, as this can damage fragile peptide structures. Step 5: Allow the BAC water to dissolve the peptide. Swirl gently if needed. Most peptides dissolve within 30-60 seconds. Do not shake vigorously. Step 6: Once fully dissolved, the reconstituted solution is ready for use. Label the vial with the date of reconstitution, peptide name, concentration (mg/mL), and total volume.

The volume of BAC water added determines the concentration of the resulting solution. A lower volume yields a higher concentration (fewer units per dose), while a higher volume yields a lower concentration (more units per dose, easier to measure with insulin syringes). The choice of volume is a practical consideration that does not affect the peptide’s biological activity.

The most frequently searched BAC water question is “how much BAC water” for specific peptides. The answer depends on the peptide vial size and the desired concentration. Below is a quick reference for popular Healius peptides using common reconstitution volumes.

For Retatrutide (10mg vial): adding 2.0 mL BAC water yields 5 mg/mL. Adding 1.0 mL yields a 10 mg/mL solution. For the 5mg vial, adding 1.0 mL yields 5 mg/mL.

For BPC-157 (5 mg vial): adding 1.0 mL BAC water yields a 5 mg/mL solution. Adding 2.0 mL yields a final concentration of 2.5 mg/mL. For the 10mg vial, adding 2.0 mL yields 5 mg/mL.

For GHK-Cu (50mg vial): adding 2.0 mL BAC water yields a 25 mg/mL solution. Adding 5.0 mL yields a final concentration of 10 mg/mL. Multiple BAC water vials may be needed for higher-volume reconstitution.

For Tesamorelin (5 mg vial): adding 1.0 mL BAC water yields a 5 mg/mL solution. Adding 2.0 mL yields a final concentration of 2.5 mg/mL.

For MOTS-c (10 mg vial): adding 1.0 mL BAC water yields a 10 mg/mL solution. Adding 2.0 mL yields a final concentration of 5 mg/mL.

For Sermorelin (5 mg or 10mg vial): adding 1.0 mL to the 5 mg vial yields 5 mg/mL. Adding 2.0 mL to the 10mg vial yields 5 mg/mL.

For Ipamorelin (5 mg vial): adding 1.0 mL BAC water yields a 5 mg/mL solution. Adding 2.0 mL yields a final concentration of 2.5 mg/mL.

For precise dose-to-unit conversions after reconstitution, use our peptide dosage calculator. The calculator converts your reconstitution volume and desired dose into exact syringe units, eliminating manual calculation errors.

The comparison between bacteriostatic water and sterile water for injection is critical for research protocol design, and the distinction has direct implications for peptide stability and contamination risk.

Bacteriostatic water contains 0.9% benzyl alcohol preservative. This allows the vial to be punctured multiple times over 28 days while maintaining sterility, because the preservative continuously suppresses microbial growth. BAC water is the correct choice for any peptide that will be dosed across multiple research sessions from the same reconstituted vial.

Sterile water for injection (SWFI) contains no preservative. It is sterile at the time of manufacture. Still, it loses its sterility guarantee the moment the vial septum is punctured, because there is no preservative to prevent bacterial growth from any contamination introduced through the needle. Sterile water should be used for single-access applications only: if the entire reconstituted volume will be used in one session, sterile water is acceptable. For multi-dose vials (the standard use case for research peptides), BAC water is required.

Normal saline (0.9% sodium chloride) is not the same as BAC water and is generally not recommended for peptide reconstitution unless specified by a particular protocol. The sodium chloride can alter the ionic environment and potentially affect peptide stability or solubility. BAC water provides a neutral aqueous environment with only benzyl alcohol as a preservative.

In summary, for virtually all research peptide reconstitution where the vial will be accessed more than once, BAC water is the correct and recommended diluent.

BAC water storage and shelf life are among the most frequently searched topics, and the answers depend on whether the vial is unopened or has been accessed.

Unopened BAC water vials have a shelf life determined by the manufacturer, typically 2-3 years from the date of manufacture when stored at controlled room temperature (20-25 degrees C / 68-77 degrees F). The expiration date is printed on each vial. Store unopened vials at room temperature in a dry place, away from direct sunlight and heat sources. Refrigeration of unopened vials is not required, but it will not harm the product.

Once a BAC water vial has been punctured (opened), the 28-day use window begins regardless of how much water remains in the vial. After 28 days from the first puncture, the vial should be discarded even if water remains. The benzyl alcohol preservative maintains sterility during this window, but its effectiveness diminishes over time as the preservative concentration can decrease with each access, increasing the cumulative contamination risk.

After puncturing, BAC water should be stored at controlled room temperature or refrigerated at 2-8 degrees C. Refrigeration is not strictly required for the BAC water itself. Still, since it is typically stored alongside reconstituted peptides (which do require refrigeration), most researchers keep both in the refrigerator for convenience. Do not freeze BAC water.

Signs that BAC water should not be used: visible particulate matter, cloudiness, discoloration (also spelled discoloration), or a compromised vial seal. If any of these are observed, discard the vial and use a fresh one.

The number of BAC water vials needed depends on the total volume of BAC water required for your reconstitution protocol and the number of peptide vials being reconstituted.

Each Healius BAC water vial contains 10 mL. If you are reconstituting a single peptide vial with 1-2 mL of BAC water, one BAC water vial will support 5-10 peptide reconstitutions. For larger reconstitution volumes (e.g., 5 mL for a 50mg GHK-Cu vial), one BAC water vial supports 2 reconstitutions.

As a general rule, order one BAC water vial for every 2-5 peptide vials in your research order, depending on your reconstitution volumes. For orders involving multiple peptides or extended research protocols, ordering 2-3 BAC water vials ensures you will not run out mid-protocol. Remember that each BAC water vial should be used within 28 days of first puncture, so factor in your anticipated usage rate.

Healius includes BAC water as a standard catalog item so that researchers can source their diluent from the same verified supplier as their peptides, ensuring consistent quality and avoiding the need to source from separate vendors.

BAC water quality matters more than many researchers realize (also spelled realize). Substandard bacteriostatic water, whether it contains incorrect preservative concentrations, endotoxins, particulates, or pH deviations, can compromise peptide stability, introduce confounding variables into research, and cause injection-site reactions that are incorrectly attributed to the peptide rather than the diluent.

Healius BAC water meets USP specifications for bacteriostatic water for injection: verified sterility, endotoxin levels within limits, 0.9% benzyl alcohol concentration confirmed, pH 4.5-7.0, and particulate matter within specification. Each vial is sealed in tamper-evident packaging to ensure integrity from manufacture to delivery.

Available in 10ml vials, Healius BAC water is designed to pair with our full range of research peptides. Whether you are reconstituting BPC-157, Retatrutide, Sermorelin, or any other peptide in our catalog, Healius BAC water provides the consistent, verified-quality diluent your research requires. Visit our Lab Testing page for quality documentation and our shipping policy page for delivery information.

1. USP (United States Pharmacopeia). Bacteriostatic Water for Injection monograph. Specifications: sterile, 0.9% benzyl alcohol, pH 4.5-7.0, endotoxin limits, particulate matter limits.

2. Benzyl alcohol as bacteriostatic preservative: inhibits microbial growth at 0.9% concentration, enabling multi-dose vial access over 28 days—standard pharmaceutical excipient.

3. FDA Guidance for Industry. Container Closure Systems for Packaging Human Drugs and Biologics. Multi-dose container requirements, including preservative effectiveness.

4. General reconstitution principles for lyophilized peptides: direct stream against glass wall, gentle swirling, no vigorous shaking, sterile technique, 28-day use window after reconstitution.