Tirzepatide Dosing Calculator & Reconstitution Guide
A dual GIP/GLP-1 receptor agonist for blood sugar control and weight loss.
To calculate a tirzepatide dose, divide the vial milligrams by the bacteriostatic water added to find mg/mL, then divide your weekly dose by that concentration. Example: a 10 mg vial in 2 mL water is 5 mg/mL, so a 2.5 mg dose is 0.5 mL — 50 units on a U-100 insulin syringe.
- Category
- GLP-1 receptor agonist
- Dose unit
- mg
- Commonly reported range
- 2.5-15 mg
- Typical concentration
- 5 mg/mL
Use the Keel dose calculator to enter your numbers and see the exact units to draw, or use the built-in calculator further down this page.
What is Tirzepatide?
Tirzepatide is a dual glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 receptor agonist dosed once weekly. Like semaglutide it is titrated gradually. Reconstituted tirzepatide is dosed in milligrams; community and anecdotal reports commonly describe maintenance doses in the 2.5 mg to 15 mg per week range. Also known as Mounjaro, Zepbound, tirz.
How many units is each Tirzepatide dose?
| Dose | Volume to draw | Units (U-100) |
|---|---|---|
| 2.5 mg | 0.5 mL | 50 units |
| 5 mg | 1 mL | 100 units |
| 7.5 mg | 1.5 mL | 150 units |
| 10 mg | 2 mL | 200 units |
| 12.5 mg | 2.5 mL | 250 units |
| 15 mg | 3 mL | 300 units |
Based on a 10 mg vial reconstituted with 2 mL of bacteriostatic water (5 mg/mL) and a U-100 insulin syringe. The dose amounts shown are commonly reported by the community and in anecdotal research, not recommendations or medical advice; only the reconstitution math (volume and units) is calculated for you.
How to calculate a Tirzepatide dose
- 1
Choose your vial and water
Select your Tirzepatide vial size (for example 10 mg) and the volume of bacteriostatic water you will add (for example 2 mL).
- 2
Find the concentration
Divide vial milligrams by water volume. 10 mg in 2 mL gives 5 mg/mL.
- 3
Calculate the draw
Divide your target dose by the concentration to get the volume in mL, then multiply by 100 to get units on a U-100 insulin syringe.
- 4
Verify on the syringe
Use the Keel calculator to see the exact draw rendered on a to-scale syringe, with a warning if the dose exceeds the syringe capacity.
Tirzepatide dosing FAQ
How many units is 2.5 mg of tirzepatide?
At 5 mg/mL (a 10 mg vial in 2 mL of bacteriostatic water), 2.5 mg equals 0.5 mL, or 50 units on a U-100 insulin syringe. Change the vial size or water volume and the unit count changes, so recalculate each time.
How do I reconstitute a 10 mg tirzepatide vial?
Add bacteriostatic water slowly down the vial wall, swirl gently, and let it dissolve. Adding 2 mL yields 5 mg/mL. Many users prefer 1 mL for a more concentrated solution that keeps the draw small.
Is tirzepatide dosing the same as Mounjaro or Zepbound?
Tirzepatide is the active ingredient in Mounjaro and Zepbound. Weekly milligram targets are comparable, but branded products are pre-filled pens. This tool is for drawing reconstituted tirzepatide from a vial.
What tirzepatide maintenance doses do people report?
Community and anecdotal reports commonly describe titrating from 2.5 mg weekly through 5, 7.5, 10, 12.5, and up to 15 mg, stepping up every few weeks. These are reported figures, not a recommendation; recalculate the draw at each step and consult a licensed professional.
Which syringe should I use for tirzepatide?
A 0.5 mL or 1 mL insulin syringe is common because higher doses can exceed the 30-unit capacity of the smallest syringe. The calculator warns you when a draw is larger than the selected syringe.
Tirzepatide side effects
See the adverse effects most commonly reported for Tirzepatide and its class, and log your own experience over time, in the Peptide & GLP-1 Side Effects reference & tracker.