How to reconstitute Tirzepatide
Tirzepatide is sold as a freeze-dried powder, most often in 5 mg, 10 mg, 15 mg, 20 mg, 30 mg, 60 mg vials. Add bacteriostatic water, let it dissolve without shaking, and the concentration is the vial amount divided by the water: 30 mg in 3 mL is 10 mg/mL. On a U-100 insulin syringe one unit is 0.01 mL, so each unit carries 100 mcg, and a 2.5 mg dose is 25 units.
The FDA label starts at 2.5 mg once weekly for four weeks, then increases in 2.5 mg steps every four weeks or more to a maximum of 15 mg. Nothing on this page is a dosing recommendation; the calculator converts a dose you already have into syringe units.
Tirzepatide doses in syringe units (30 mg vial, 3 mL water)
| Dose | Units | mL | Doses per vial |
|---|---|---|---|
| 2.5 mg | 25 | 0.25 | 12 |
| 5 mg | 50 | 0.5 | 6 |
| 7.5 mg | 75 | 0.75 | 4 |
| 10 mg | 100 | 1 | 3 |
| 12.5 mg | 125 | 1.25 | 2 |
| 15 mg | 150 | 1.5 | 2 |
Vial sizes at 2.5 mg per dose
| Vial | Water | Concentration | Units per dose | Doses |
|---|---|---|---|---|
| 5 mg | 3 mL | 1.67 mg/mL | 150 | 2 |
| 10 mg | 3 mL | 3.33 mg/mL | 75 | 4 |
| 15 mg | 3 mL | 5 mg/mL | 50 | 6 |
| 20 mg | 3 mL | 6.67 mg/mL | 37.5 | 8 |
| 30 mg | 3 mL | 10 mg/mL | 25 | 12 |
| 60 mg | 3 mL | 20 mg/mL | 12.5 | 24 |
The dose column is in mg. Doubling the water halves the concentration and doubles the units per dose; the number of doses in the vial never changes. If a dose comes out under 5 units, use less water so it is easier to measure. If it exceeds the syringe, use more water or a bigger syringe.
Worked example
30 mg / 3 mL = 10 mg/mL = 10,000 mcg/mL. One unit = 0.01 mL = 100 mcg. 2,500 mcg / 100 mcg per unit = 25 units. The vial holds 30,000 / 2,500 = 12 doses, which at 1 per week is about 84 days.
See the general peptide calculator for the formulas, syringe sizes, and the common mg versus mcg mistakes.