WeightSnap Tools / Tirzepatide reconstitution
Enter your tirzepatide vial size, how much bacteriostatic water you add, and your dose. Get the concentration, the volume to draw, and the insulin syringe units. Compounded tirzepatide vials are commonly 10mg, 20mg, 30mg, or 60mg. The chart below is printable for taping to your fridge.
Common tirzepatide vial and bacteriostatic water combinations, with the resulting concentration and the U-100 syringe units for reference dose points. Pure arithmetic; your protocol is between you and your provider.
| Vial + water | Concentration | 2.5 mg | 5 mg | 7.5 mg | 10 mg | 15 mg |
|---|---|---|---|---|---|---|
| 10 mg + 1 mL | 10 mg/mL | 25 | 50 | 75 | 100 | 150 |
| 20 mg + 1 mL | 20 mg/mL | 12.5 | 25 | 37.5 | 50 | 75 |
| 30 mg + 1.5 mL | 20 mg/mL | 12.5 | 25 | 37.5 | 50 | 75 |
| 60 mg + 3 mL | 20 mg/mL | 12.5 | 25 | 37.5 | 50 | 75 |
Units = (dose ÷ concentration) × 100. A U-100 syringe holds 100 units (1 mL); anything over 100 units will not fit in one syringe.
Reconstitution is one division and one multiplication. The water you add sets the concentration, and the concentration turns your dose into a syringe reading.
Worked example: a 30mg tirzepatide vial with 1.5mL of bacteriostatic water gives 20 mg/mL. A 5mg dose is 5 ÷ 20 = 0.25 mL, which reads 25 units on a U-100 syringe. Add more water for a lower concentration and higher unit count.
Add bacteriostatic water to the powder vial and let it dissolve without shaking. The water volume sets the concentration: a 30mg vial with 1.5mL gives 20 mg/mL. Enter your vial and water above to see the concentration and the units for your dose.
A table showing, for common vial and water combinations, the resulting concentration and the U-100 syringe units for reference doses. The chart above covers 10mg, 20mg, 30mg, and 60mg vials. It is arithmetic for reference, not a dosing recommendation.
It depends on the concentration you want. More water means a more dilute mix and a larger draw. A common choice for a 30mg vial is 1.5mL (20 mg/mL). Your dose and schedule are set by your prescriber.
This calculator is for reconstituting powder vials, such as compounded tirzepatide. Brand pens (Mounjaro, Zepbound) come pre-filled and do not need reconstitution, so the math here does not apply to them.
No. It performs arithmetic on the numbers you enter and makes no recommendations about dose or product. Always confirm anything affecting your health with your pharmacist or provider.
WeightSnap is a tracking tool, not medical advice. This calculator performs arithmetic on the numbers you enter and makes no recommendations. Always work with your healthcare provider.
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