Bacteriostatic water vs sterile water
2 min read
What's the difference?
| Bacteriostatic water | Sterile water for injection | |
|---|---|---|
| Preservative | 0.9% benzyl alcohol | None |
| Use | Can be drawn from more than once | Single use, then discard |
| After opening | Commonly up to 28 days, unless the label says otherwise | Use straight away |
| Notes | Not for newborns. Can sting slightly. | Better when a product says not to use preservatives |
Which one should I use?
Whichever your product's instructions or your pharmacist specify. Most multi-dose peptide vials are mixed with bacteriostatic water so the preservative protects the vial between draws. A few products need a different liquid altogether.
Does the 28-day rule apply to my peptide?
Not automatically. The 28-day figure is a general guide for opened multi-dose vials of bacteriostatic water. Once a peptide is dissolved, its own stability matters too, and that varies by product. Use the shorter of the two, and set it as the "use within" period in the app so you get a reminder.
Can I use tap water, saline or boiled water?
No. Tap and boiled water are not sterile. Saline is sometimes used for specific products only when the instructions say so.
Keep reading
Mixing a vial (reconstitution), step by step
2 min read
Storing peptides: fridge, handling and travel
2 min read
General information, not medical advice. Always follow your product's instructions and your healthcare professional.