Short answer: 2 mL of bacteriostatic water in a 30 mg tirzepatide vial makes 15 mg/mL. On a U-100 insulin syringe (1 mL = 100 units), every 10 units then holds 1.5 mg. More water gives a weaker solution and a bigger draw for the same amount; the amount in the vial stays 30 mg.
| Water added | Concentration | Per 10 units | Per 1 unit |
|---|---|---|---|
| 1 mL | 30 mg/mL | 3 mg | 300 mcg |
| 2 mL | 15 mg/mL | 1.5 mg | 150 mcg |
| 3 mL | 10 mg/mL | 1 mg | 100 mcg |
| 5 mL | 6 mg/mL | 600 mcg | 60 mcg |
The amounts below are examples to show the conversion, not doses. How much to take is a decision for you and your prescriber.
| Water added | 1.25 mg | 2.5 mg | 5 mg |
|---|---|---|---|
| 1 mL | 4.2 units | 8.3 units | 16.7 units |
| 2 mL | 8.3 units | 16.7 units | 33.3 units |
| 3 mL | 12.5 units | 25 units | 50 units |
| 5 mL | 20.8 units | 41.7 units | 83.3 units |
A 30 mg vial holds 24 draws of 1.25 mg, 12 draws of 2.5 mg, 6 draws of 5 mg, no matter how much water you add.
30 mg ÷ 2 mL = 15 mg/mLamount ÷ 15 mg/mL = mLmL × 100 = unitsFor a different water volume or amount, the free peptide reconstitution calculator works backwards from the amount you want and suggests a water volume that lands on a clean syringe mark.
Tirzepatide 5 mg · Tirzepatide 10 mg · Tirzepatide 15 mg · Tirzepatide 20 mg
Half-life, time to peak and sources are on the main Tirzepatide guide.