Tirzepatide dose calculator
Convert your tirzepatide vial, BAC water, and prescribed dose into insulin-syringe units — instantly. Free, no account, nothing leaves your browser. Works for compounded Mounjaro and Zepbound.
Draw to
8.3 units
on a U-100 insulin syringe (0.083 mL)
Concentration
30 mg/mL
Doses per vial
~12
How it works: concentration = vial strength ÷ BAC water. Volume to draw = your dose ÷ concentration. On a U-100 insulin syringe, 100 units = 1 mL, so units = volume × 100. Always confirm your tirzepatide vial strength and prescribed dose with your prescriber or pharmacist — this tool is for educational reference only and is not medical advice.
How tirzepatide reconstitution works
Compounded tirzepatide usually arrives as a freeze-dried powder you reconstitute with bacteriostatic water. Two numbers drive everything: the vial strength (total mg) and the amount of BAC water you add. Together they set the concentration (mg/mL), which determines how many units to draw for each dose. Once you know your concentration, log every injection and watch your titration in the private compounded tirzepatide tracker. For the full titration ladder, see the tirzepatide dosing schedule.
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Frequently asked questions
How do I convert tirzepatide mg to units?
First find your concentration: divide the vial strength (mg) by the amount of bacteriostatic water you added (mL). Then divide your prescribed dose (mg) by that concentration to get the volume in mL, and multiply by 100 to get units on a U-100 insulin syringe. For example, a 30 mg vial reconstituted with 1 mL of BAC water is 30 mg/mL; a 2.5 mg dose is 0.083 mL, which is about 8 units.
How much bacteriostatic water do I add to a tirzepatide vial?
It depends on the vial and the concentration your provider wants. Common choices are 1 mL or 2 mL of bacteriostatic water. More water makes a lower concentration (more units per dose, easier to measure small doses); less water makes a higher concentration. Always follow the reconstitution instructions from your compounding pharmacy or prescriber.
What syringe should I use?
This calculator assumes a standard U-100 insulin syringe, where 100 units equals 1 mL. If you use a different syringe, the unit markings may differ — verify against the actual volume in mL.
Is this calculator medical advice?
No. It is an educational reference tool. Compounded tirzepatide is not FDA-approved and concentrations vary between pharmacies. Always confirm your vial strength, reconstitution, and dose with your prescriber or pharmacist before injecting.
This calculator is for general educational purposes only and is not medical advice. Compounded tirzepatide is not FDA-approved and formulations vary. Always confirm your vial strength, reconstitution, and dose with your prescriber or pharmacist before injecting.