Your prescription is written in milligrams (like 2.5 mg or 5 mg), but your syringe is marked in units. Here is how the two connect.
The basics
On a standard insulin syringe, 100 units = 1 mL
How many units equal your dose in mg depends on one thing: the concentration of your vial (mg per mL)
Read your vial label first
Always check the vial label before you draw. The label shows the tirzepatide concentration, and that number determines how many units you draw. The same prescribed dose requires a different number of units at a different concentration, so never reuse old numbers from a previous vial without checking.
Your label may also list vitamin B6. Ignore the B6 number when figuring your dose: only the tirzepatide concentration matters.
How the math works
Units to draw = (your dose in mg ÷ vial concentration in mg/mL) × 100
Example: with a 10 mg/mL vial, a 2.5 mg dose is 25 units. With a 20 mg/mL vial, that same 2.5 mg dose is about 13 units. Same dose, half the volume, because the medication is twice as concentrated.
Don't guess
Your dosing instructions show the exact units to draw for your prescribed dose. If your label is unclear, or your vial looks different from your last shipment, do not guess. Message your provider through your Crossing account before injecting. Drawing from the wrong table can mean getting double or half your dose.