Dual GIP/GLP-1 receptor agonist

Tirzepatide dosage calculator

Reconstitute tirzepatide (Mounjaro, Zepbound) from a lyophilized vial and get the exact units to draw. Enter your vial strength in mg, bacteriostatic water volume, and weekly dose for the precise mark on a U-100 insulin syringe.

Your reconstitution
Vial sizemg
Bacteriostatic water addedmL
Desired dosemg per injection
2.5 mg
0.5 mg steps · capped at your vial size

Draw to

12.5units on a U-100 insulin syringe

Draw to the 12.5 unit mark. That is 0.125 mL of solution.

Concentration20mg per mL
Volume to draw0.125mL
Doses per vial24injections

Informational and educational only. Not medical advice. This tool performs math on values you enter and is not a substitute for your prescriber.

Typical titration schedule

Standard ramp

Units to draw are calculated from your current vial and water settings above and update live.

PeriodDoseDraw (units)Volume
Weeks 1-4current2.5 mg12.50.125 mL
Weeks 5-85 mg250.250 mL
Weeks 9-127.5 mg37.50.375 mL
Weeks 13-1610 mg500.500 mL
Weeks 17-2012.5 mg62.50.625 mL
Week 21+15 mg750.750 mL

Tirzepatide has an elimination half-life of approximately 5 days, which supports once-weekly dosing.

Source: FDA Mounjaro (tirzepatide) Prescribing Information

Common questions

How do I reconstitute tirzepatide?

Add your chosen volume of bacteriostatic water to the lyophilized vial, directing the stream against the glass wall, and swirl gently (do not shake) until fully dissolved. The calculator converts your vial strength and water volume into the units to draw for your target dose.

How many units of tirzepatide is 2.5 mg?

It depends on your concentration. With a 30 mg vial in 3 mL of water (10 mg/mL), 2.5 mg is 0.25 mL, or 25 units on a U-100 syringe. Enter your own vial and water amounts above to get your exact number.

Source: FDA Mounjaro (tirzepatide) Prescribing Information · How we calculate