Tirzepatide Units

How Many Units Is 15 mg of Tirzepatide?

It depends on the vial strength. 15 mg of tirzepatide is 50 units (0.5 mL) from a brand single-dose vial labeled 15 mg/0.5 mL, 60 units (0.6 mL) from a brand multi-dose vial labeled 60 mg/2.4 mL, and 150 units (1.5 mL) from a compounded vial at 10 mg/mL. For any other compounded concentration, enter it below.

Follow your prescription and pharmacy label. Ask the prescriber or pharmacist if anything is unclear.

1. Which vial?
Vial type

Concentration: 15 mg ÷ 0.5 mL = 30 mg/mL. The label dose is 0.5 mL, the whole vial.

2. Convert
3. Syringe (U-100)
Calculated dose

15 mg = 50 units(0.5 mL at 30 mg/mL)

  1. Step 1. Concentrationmg/mL = mg in vial ÷ mL in vial
    15 mg ÷ 0.5 mL = 30 mg/mL
  2. Step 2. VolumemL = mg ÷ (mg/mL)
    15 ÷ (15 ÷ 0.5) = 0.5 mL
  3. Step 3. Units on a U-100 syringeunits = mL × 100
    0.5 × 100 = 50 units
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15 mg in units by vial strength

Tirzepatide brand vials (Zepbound and Mounjaro labels, section 3)
DoseSingle-dose vialDrawMulti-dose vialDraw
15 mg15 mg/0.5 mL0.5 mL = 50 units60 mg/2.4 mL (25 mg/mL)0.6 mL = 60 units
Compounded vials: mL and units at example concentrations
Dose5 mg/mL10 mg/mL15 mg/mL20 mg/mL25 mg/mL
15 mg3 mL = 300 u *1.5 mL = 150 u *1 mL = 100 u0.75 mL = 75 u0.6 mL = 60 u

* More than 100 units: does not fit in a 1 mL syringe in one draw.

The steps for 15 mg

Single-dose vial, 15 mg/0.5 mL

  1. Concentration: 15 mg ÷ 0.5 mL = 30 mg/mL
  2. Volume: 15 ÷ (15 ÷ 0.5) = 0.5 mL
  3. Units on a U-100 syringe: 0.5 × 100 = 50 units

Result: 15 mg = 0.5 mL = 50 units

Multi-dose vial, 60 mg/2.4 mL

  1. Concentration: 60 mg ÷ 2.4 mL = 25 mg/mL
  2. Volume: 15 ÷ (60 ÷ 2.4) = 0.6 mL
  3. Units on a U-100 syringe: 0.6 × 100 = 60 units

Result: 15 mg = 0.6 mL = 60 units

Compounded vial, 10 mg/mL

  1. Concentration: 10 mg/mL (from the pharmacy label)
  2. Volume: 15 ÷ 10 = 1.5 mL
  3. Units on a U-100 syringe: 1.5 × 100 = 150 units

Result: 15 mg = 1.5 mL = 150 units

Where 15 mg sits in the dose escalation

In the label, 15 mg comes after at least 4 weeks on 12.5 mg; the earliest it can start is week 21. Zepbound lists 15 mg as a maintenance dose for both weight reduction and obstructive sleep apnea. 15 mg is the maximum dose for adults. The prescriber decides which dose to use and when.

The Zepbound and Mounjaro labels start at 2.5 mg once weekly for 4 weeks. 2.5 mg is only for starting treatment, not a maintenance dose. After that the dose goes up in 2.5 mg steps, with at least 4 weeks on each dose. Zepbound lists 5 mg, 10 mg or 15 mg as maintenance doses for weight reduction and 10 mg or 15 mg for obstructive sleep apnea. The maximum is 15 mg once weekly. The weeks in the table are the earliest a dose can start under the label; the prescriber decides the actual schedule.

Full schedule with mL and units: tirzepatide dosage chart.

Units vs mg

A mg (milligram) is the amount of tirzepatide. A unit is a mark on a U-100 insulin syringe, and on a U-100 syringe 100 units fill 1 mL, so 1 unit is 0.01 mL. Units measure volume, not drug. How much tirzepatide is in those units depends on how concentrated the liquid is.

Why the vial concentration matters

The same dose can be very different volumes. 2.5 mg is 25 units only at 10 mg/mL. At 5 mg/mL it is 50 units, and at 25 mg/mL it is 10 units. That is why this calculator asks for the vial first and never assumes a concentration.

Brand vs compounded vials

Brand tirzepatide vials (Zepbound and Mounjaro) are made so every dose is the same volume: 0.5 mL (50 units) from a single-dose vial, or 0.6 mL (60 units) from a multi-dose vial that holds 4 doses. The vial strength changes with the dose instead. Compounded vials are prepared by a pharmacy at a concentration of its choosing, so the volume for a given dose changes from vial to vial. Read the mg/mL on the pharmacy label.

Other tirzepatide doses in units

Or use the tirzepatide units to mg calculator for any dose and concentration.

Frequently asked questions

How many units is 15 mg of tirzepatide?
It depends on the vial. In a brand single-dose vial (15 mg/0.5 mL) 15 mg is 0.5 mL, or 50 units. In a brand multi-dose vial (60 mg/2.4 mL) it is 0.6 mL, or 60 units. In a compounded vial at 10 mg/mL it is 1.5 mL, or 150 units.
How many mL is 15 mg of tirzepatide?
0.5 mL from a brand single-dose vial and 0.6 mL from a brand multi-dose vial. For a compounded vial, divide 15 by the mg/mL on the label: at 10 mg/mL that is 1.5 mL.
Is 15 mg always 150 units?
No. 15 mg is 150 units only when the concentration is exactly 10 mg/mL. Brand vials are 30 mg/mL (single-dose) and 25 mg/mL (multi-dose), so the same 15 mg is 50 or 60 units there.
What concentration is a 15 mg tirzepatide vial?
The single-dose vial is 15 mg/0.5 mL, which is 15 ÷ 0.5 = 30 mg/mL. The multi-dose vial is 60 mg/2.4 mL, which is 60 ÷ 2.4 = 25 mg/mL.

Sources

Doses and vial strengths checked against these labels on 2026-10-22.