Peptide Reconstitution Calculator
Work out exactly how much bacteriostatic water to add to a peptide vial — and how many units to draw on an insulin syringe for your target dose. Enter the vial strength, the water you plan to add, and your dose. You get the concentration, the volume per dose, the units to draw on your chosen syringe, how many doses the vial yields, and (optionally) the cost per dose. It is an educational aid for handling research materials, not medical advice.
Peptide Reconstitution Calculator
Educational tool for handling research materials — not medical advice or a dosing recommendation. Confirm anything you act on with a qualified clinician.
How to use it
- Vial strength (mg). Enter the total peptide in the vial, printed on the label. A “5 mg” vial is 5.
- Bacteriostatic water (mL). Enter how much water you plan to add. More water gives more units per dose, which is easier to measure. Less water gives fewer units per dose.
- Target dose. Enter the dose you want and pick mcg or mg.
- Syringe. Pick your insulin syringe size. The diagram adjusts. You get a warning if one dose is bigger than the syringe holds.
- Read the result. The “units to draw” figure is the mark to pull to on a U-100 insulin syringe. Use the round-units tip to land your dose on a clean 10- or 20-unit mark.
Tip: keep the same water volume for a compound. Your usual dose then lands on the same mark every time. That cuts measurement error.
Frequently asked questions
How much bacteriostatic water should I add?
It depends on the vial strength and the dose you want. A practical approach is to pick a water volume that lands your usual dose on a round number of units, like 10 or 20. That is easier to measure. The round-units tip does this math for you.
What do the “units” mean?
They are the marks on a U-100 insulin syringe, where 100 units equal 1 mL. The calculator converts your per-dose volume into that mark, so you know how far to draw.
Can I use sterile water instead?
Sterile water has no preservative. A vial mixed with it is usually treated as single-session. Bacteriostatic water contains a little benzyl alcohol, which suppresses microbes. That makes it the usual choice for a multi-draw vial kept cold.
Why does one dose “not fit” my syringe?
If one dose needs more units than your syringe holds, the tool flags it. To fix it, use less water for a more concentrated mix, split the dose across two draws, or use a larger syringe.
How long does the mixed vial last?
Kept cold at 2–8°C and mixed with bacteriostatic water, about four weeks is the common limit. See the storage & handling guide for the full picture.