Bacteriostatic Water for Peptides: Complete Guide to BAC Water
Everything you need to know about bacteriostatic water for peptide reconstitution. Learn what it is, how to use it, storage guidelines, and alternatives.
What is Bacteriostatic Water?
Bacteriostatic water (BAC water) is sterile water that contains 0.9% benzyl alcohol as a preservative. This preservative inhibits bacterial growth, making it safe for multiple uses from the same vial.
Key Characteristics
- Composition: Sterile water + 0.9% benzyl alcohol
- pH: Near neutral (approximately 4.5-7.0)
- Preservative action: Bacteriostatic (stops growth), not bactericidal (kills)
- Multi-use: Safe for multiple withdrawals
- A 5mg vial might provide 20+ doses
- Each withdrawal introduces potential contamination
- Without preservative, bacteria can multiply
- Benzyl alcohol prevents bacterial reproduction
- Solution remains safe throughout use period
- Extends practical vial life to 28+ days
- Standard choice for peptide reconstitution
- Multiple doses from one vial
- Single-use situations only
- Benzyl alcohol sensitivity
- Must discard after opening
- Room temperature (59-86°F / 15-30°C)
- Protected from light
- Check expiration date
- Inspect for cloudiness/particles
- Remove caps from both vials
- Wipe rubber stoppers with alcohol
- Draw desired BAC water amount
- Inject slowly into peptide vial
- Allow to dissolve (don't shake)
- Store reconstituted peptide properly
- Store at room temperature or refrigerated
- Use within 28 days of opening
- Mark opening date on vial
- Inspect before each use
- Benzyl alcohol concentration is low
- Peptides remain stable
- Millions of doses used safely
- Sterility is critical
- Precise concentration matters
- Commercial products are reliable and inexpensive
- Risk of contamination is too high
- USP grade designation
- Clear, colorless solution
- Sealed properly
- Valid expiration date
- Reputable supplier
- Neonates (infants)
- Those with known sensitivity
- When directed by healthcare provider
- Sterile water (single use only)
- Reconstitute smaller amounts more frequently
- Consult healthcare provider for options
Why BAC Water for Peptides?
The Multi-Dose Problem
Peptide vials are typically used multiple times:
How BAC Water Protects
BAC Water vs. Alternatives
Comparison Chart
| Water Type | Preservative | Multi-Use | Best For |
| Bacteriostatic | Yes (benzyl alcohol) | Yes | Multi-dose peptides |
| Sterile Water | No | Single use only | IV medications |
| Sodium Chloride 0.9% | No | Single use | Some medications |
| BAC Saline | Yes | Yes | Some applications |
| Peptide Amount | BAC Water | Concentration | |
| 5mg | 1mL | 5mg/mL | |
| 5mg | 2mL | 2.5mg/mL | |
| 5mg | 2.5mL | 2mg/mL | |
| 10mg | 2mL | 5mg/mL | |
| Condition | Duration | ||
| Room temperature | Until expiration | ||
| Refrigerated | Until expiration | ||
| Condition | Duration | ||
| Room temperature | 28 days | ||
| Refrigerated | 28 days | ||
| Condition | Duration | ||
| Refrigerated | 28-42 days (peptide dependent) | ||
| Room temperature | Use immediately or discard |
Quality Considerations
What to Look For
Red Flags
⚠️ Unusual color or cloudiness
⚠️ Particles visible
⚠️ Damaged seal
⚠️ Unknown source
⚠️ Past expiration
Benzyl Alcohol Sensitivity
Who Should Avoid
Alternatives if Sensitive
Frequently Asked Questions
Q: Can I use regular water?
A: Never. Tap water contains microorganisms and minerals that can damage peptides and cause infection.
Q: How long does BAC water last in a vial?
A: 28 days after opening, regardless of refrigeration.
Q: Is it okay if BAC water is slightly yellow?
A: No. It should be completely clear and colorless. Discard if discolored.
Q: Can I refrigerate unopened BAC water?
A: Yes, but room temperature is fine. Either is acceptable.
Q: Do I need a prescription for BAC water?
A: In most jurisdictions, no. It's available at many pharmacies and online.
Conclusion
Bacteriostatic water is an essential supply for anyone using peptides. Its preservative properties allow safe multi-dose use, making it the standard choice for peptide reconstitution. Always use quality products, store properly, and track your opening dates for safety.
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