Quick math example
A 10 mg vial mixed with 2 mL gives 5 mg/mL. A 2.5 mg dose is 0.5 mL, which equals 50 units on a U-100 syringe.
10 mg tirzepatide vial examples
A 10 mg vial in 2 mL gives 5 mg/mL. A 2.5 mg dose is 0.5 mL, or 50 units on a U-100 syringe.
Prefer smaller draws? 1 mL of BAC water gives 10 mg/mL, so 2.5 mg becomes 0.25 mL (25 units).
- 10 mg / 2 mL = 5 mg/mL → 2.5 mg = 0.5 mL = 50 units
- 10 mg / 1 mL = 10 mg/mL → 2.5 mg = 0.25 mL = 25 units
- A 10 mg vial yields about four 2.5 mg doses
10 mg as the middle-of-the-road tirzepatide vial
The 10 mg vial sits between the 5 mg starter size and the 15 mg maintenance size. For people titrating across the typical 2.5–12.5 mg/week range, it covers more of the journey in a single vial than a 5 mg does, without committing to the longer-life 15 mg vial.
Practical advantage: the math works out to round-number draws at common concentrations. At 5 mg/mL (10 mg in 2 mL), every milligram of dose is exactly 0.2 mL or 20 units — so 2.5 mg lands on 50, 5 mg on 100, 7.5 mg on 150 (one full draw on a 1 mL U-100 syringe).
- Covers ~4 weeks at the 2.5 mg titration step
- Round-number unit draws at 5 mg/mL: 1 mg = 20 units, 2.5 mg = 50 units, 5 mg = 100 units
- Less commitment than a 15 mg vial during titration changes
How the tirzepatide calculation works
Tirzepatide doses are often discussed in milligrams, while many vials and syringes require you to think in mg, mcg, mL, and units at the same time.
The calculator normalizes everything into concentration first, then returns a draw volume and matching syringe-unit result.
- 10 mg equals 10,000 mcg
- 10,000 mcg / 2 mL = 5,000 mcg per mL
- 2,500 mcg / 5,000 mcg per mL = 0.5 mL
Tirzepatide 10 mg vial with 2 mL example
A 10 mg tirzepatide vial mixed with 2 mL gives 5 mg/mL, or 5,000 mcg/mL.
A 2.5 mg target dose is 2,500 mcg. At 5 mg/mL, that is 0.5 mL, which equals 50 units on a U-100 syringe.
- 10 mg / 2 mL = 5 mg/mL
- 2.5 mg = 2,500 mcg
- 2,500 mcg / 5,000 mcg per mL = 0.5 mL = 50 U-100 units
Tirzepatide 15 mg vial with 3 mL example
A 15 mg tirzepatide vial mixed with 3 mL also gives 5 mg/mL, or 5,000 mcg/mL.
Because the concentration is the same as the 10 mg with 2 mL example, a 2.5 mg dose is still 0.5 mL, or 50 U-100 units.
- 15 mg / 3 mL = 5 mg/mL
- 2.5 mg / 5 mg per mL = 0.5 mL
- 0.5 mL x 100 = 50 U-100 units
How much BAC water for tirzepatide?
Bacteriostatic water volume sets your concentration, so it directly changes the syringe units you draw. There is no single correct amount — choose a volume that puts your target dose at an easy-to-read number of units on a U-100 syringe.
For a 10 mg vial: 1 mL gives 10 mg/mL (a 2.5 mg dose = 0.25 mL = 25 units), 2 mL gives 5 mg/mL (2.5 mg = 0.5 mL = 50 units), and 3 mL gives about 3.33 mg/mL (2.5 mg = 0.75 mL = 75 units).
- More BAC water = lower concentration = more units for the same dose
- 10 mg / 1 mL = 10 mg/mL; 10 mg / 2 mL = 5 mg/mL; 10 mg / 3 mL = 3.33 mg/mL
- Aim for a draw that lands on clear unit markings to reduce dosing error
When to re-check the math
Recalculate when you change vial size, BAC water volume, dose, syringe type, or syringe capacity. Saving the setup in PepSync helps avoid re-entering the same details each week.