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Dosage Tool

Tirzepatide Reconstitution Calculator

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Written byPureCalc Editorial Team

Updated: April 27, 2026 • Verified Clinical Formula

Calculate exact injection units based on your Tirzepatide vial concentration and desired dosage. Ensure your syringe type matches the calculations before administering.

mg
mL
mg

Calculated Draw

25Units

Volume

0.25 mL

Doses per Vial

4

Pull the plunger to the 25 mark on a standard U-100 insulin syringe to administer exactly 2.5mg of Tirzepatide.

Medical Disclaimer: This calculator is provided for educational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always verify calculations with a qualified healthcare provider.

What is Tirzepatide and How Does It Work?

Tirzepatide is an FDA-approved medication developed by Eli Lilly, prescribed under the brand names Mounjaro (for Type 2 Diabetes) and Zepbound (for chronic weight management). It functions as a dual-hormone receptor agonist, targeting two key pathways:

  • GLP-1 (Glucagon-like peptide-1): Slows gastric emptying, reduces appetite, and stimulates insulin secretion.
  • GIP (Glucose-dependent insulinotropic polypeptide): Works synergistically with GLP-1 to enhance glycemic control and increase lipid metabolism.

Clinical Reconstitution Math

While commercial pens are pre-dosed, utilizing lyophilized or compounded Tirzepatide requires exact dosing math to safely follow the standard clinical titration schedule (2.5mg, 5mg, 7.5mg, 10mg, 12.5mg, 15mg).

Volume to Units Conversion
Concentration = Total mg ÷ BAC Water Added (mL)
Syringe Units = (Desired Dose (mg) ÷ Concentration) × 100

A Practical Example

Consider a patient with a 10mg vial of Tirzepatide. They add 1mL of Bacteriostatic Water to the vial. Their desired starting dose is 2.5mg.

Step 1: 10mg ÷ 1mL = 10mg per mL.
Step 2: (2.5mg ÷ 10mg/mL) × 100 = 25 Units.

The patient would draw the U-100 syringe to the "25" tick mark to administer exactly 2.5mg.