BAC Water & Peptide Reconstitution Calculator
Figure out how much bacteriostatic (BAC) water to add when reconstituting lyophilized peptides, then convert your target dose into syringe units. Free reconstitution math for BPC-157, TB-500, semaglutide, tirzepatide, CJC-1295, and other research peptides.
How reconstitution works
Lyophilized peptides arrive as a powder. Adding BAC water dissolves the powder and sets the concentration of the solution:
- Concentration = vial contents (mg) ÷ BAC water added (ml)
- Injection volume = desired dose ÷ concentration
- Syringe units = injection volume (ml) × 100 on a U-100 insulin syringe
Worked example: a 5 mg vial + 2 ml BAC water → 2.5 mg/ml (2,500 mcg/ml). A 250 mcg draw is 0.1 ml = 10 units.
More BAC water = a more dilute solution and larger syringe draws for the same dose. Less water = a more concentrated solution and smaller draws. Use this tool to pick a convenient mixing ratio, then confirm the draw for your target dose.
What it supports
- BAC water volume vs. vial size concentration math
- Target-dose → syringe-unit conversion after reconstitution
- Peptide blend reconstitution for multi-compound vials
- Link-outs from BPC-157 and TB-500 protocol guides for educational worked examples
Looking for a general dose calculator landing page? See the peptide dose calculator.
*Educational reconstitution math only — not dosing guidance. Always verify calculations and consult a licensed healthcare provider.*
Frequently asked questions
What does this calculator do?
This calculator determines your injection volume. Enter your vial size, the amount of bacteriostatic water you used to reconstitute, and your desired dose — it tells you exactly how many units to draw on your insulin syringe. For research purposes only. Always verify with your healthcare provider.
What is bacteriostatic water?
Bacteriostatic water (BAC water) is sterile water containing 0.9% benzyl alcohol used to reconstitute lyophilized peptide powder. The volume you add determines the concentration of your solution.
How do I read the syringe result?
The result shows units corresponding to tick marks on a U-100 insulin syringe. Draw up to that mark. Always double-check before use and consult your healthcare provider.
Can I use this for peptide blends?
Yes — switch to "Peptide Blend" mode to calculate volumes for multi-peptide combinations like KLOW (BPC-157, TB-500, GHK-Cu, KPV).
Can I save my calculations?
Yes — use "Load Saved Calculation" to store and reload common calculations. Create a free account to also log and track doses over time.
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