What is the tirzepatide dosing for weight loss in units?

With brand vials every dose is the same volume: 50 units (0.5 mL) from a single-dose vial or 60 units (0.6 mL) from a multi-dose vial, for every dose from 2.5 mg to 15 mg. With a compounded vial, units = mg ÷ (mg/mL) × 100, so it depends on the concentration on the label.

What is the tirzepatide dosing in mL?

0.5 mL per dose from a brand single-dose vial and 0.6 mL per dose from a brand multi-dose vial. For a compounded vial, mL = mg ÷ (mg/mL): for example 5 mg at 10 mg/mL is 0.5 mL.

How long does each tirzepatide dose step last?

The labels start at 2.5 mg once weekly for 4 weeks, then increase in 2.5 mg steps after at least 4 weeks on the current dose. The maximum is 15 mg once weekly. The prescriber sets the actual schedule.

Tirzepatide Dosage Chart

Every tirzepatide dose in the FDA labels for Zepbound and Mounjaro, from the 2.5 mg starting dose to the 15 mg maximum, with the mL and units to draw from a brand vial. Brand doses are always 0.5 mL (50 units) from a single-dose vial and 0.6 mL (60 units) from a multi-dose vial. Compounded vials depend on their concentration, shown further down.

Tirzepatide dosage chart by week

Tirzepatide dose escalation (Zepbound and Mounjaro labels), converted for brand vials

Earliest week	Dose (mg)	mL per dose	Units per dose	Label note
Week 1–4	2.5 mg	0.5 mL single-dose / 0.6 mL multi-dose	50 / 60 units	Starting dose for 4 weeks; not a maintenance dose.
Week 5+	5 mg	0.5 mL single-dose / 0.6 mL multi-dose	50 / 60 units	At least 4 weeks on 2.5 mg first. Zepbound weight maintenance option.
Week 9+	7.5 mg	0.5 mL single-dose / 0.6 mL multi-dose	50 / 60 units	At least 4 weeks on 5 mg first.
Week 13+	10 mg	0.5 mL single-dose / 0.6 mL multi-dose	50 / 60 units	At least 4 weeks on 7.5 mg first. Zepbound weight maintenance option. Zepbound sleep apnea maintenance option.
Week 17+	12.5 mg	0.5 mL single-dose / 0.6 mL multi-dose	50 / 60 units	At least 4 weeks on 10 mg first.
Week 21+	15 mg	0.5 mL single-dose / 0.6 mL multi-dose	50 / 60 units	At least 4 weeks on 12.5 mg first. Zepbound weight maintenance option. Zepbound sleep apnea maintenance option. Maximum adult dose.

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.

Brand vial strengths for each dose

Tirzepatide brand vials (Zepbound and Mounjaro labels, section 3)

Dose	Single-dose vial	Draw	Multi-dose vial	Draw
2.5 mg	2.5 mg/0.5 mL	0.5 mL = 50 units	10 mg/2.4 mL (4.17 mg/mL)	0.6 mL = 60 units
5 mg	5 mg/0.5 mL	0.5 mL = 50 units	20 mg/2.4 mL (8.33 mg/mL)	0.6 mL = 60 units
7.5 mg	7.5 mg/0.5 mL	0.5 mL = 50 units	30 mg/2.4 mL (12.5 mg/mL)	0.6 mL = 60 units
10 mg	10 mg/0.5 mL	0.5 mL = 50 units	40 mg/2.4 mL (16.67 mg/mL)	0.6 mL = 60 units
12.5 mg	12.5 mg/0.5 mL	0.5 mL = 50 units	50 mg/2.4 mL (20.83 mg/mL)	0.6 mL = 60 units
15 mg	15 mg/0.5 mL	0.5 mL = 50 units	60 mg/2.4 mL (25 mg/mL)	0.6 mL = 60 units

Compounded vials: dose in mL and units

For a compounded vial, divide the dose by the mg/mL on the pharmacy label for mL, then multiply by 100 for units. The table works this out at five example concentrations; if yours is different, use the calculator below.

Compounded vials: mL and units at example concentrations

Dose	5 mg/mL	10 mg/mL	15 mg/mL	20 mg/mL	25 mg/mL
2.5 mg	0.5 mL = 50 u	0.25 mL = 25 u	0.167 mL = 16.7 u	0.125 mL = 12.5 u	0.1 mL = 10 u
5 mg	1 mL = 100 u	0.5 mL = 50 u	0.333 mL = 33.3 u	0.25 mL = 25 u	0.2 mL = 20 u
7.5 mg	1.5 mL = 150 u *	0.75 mL = 75 u	0.5 mL = 50 u	0.375 mL = 37.5 u	0.3 mL = 30 u
10 mg	2 mL = 200 u *	1 mL = 100 u	0.667 mL = 66.7 u	0.5 mL = 50 u	0.4 mL = 40 u
12.5 mg	2.5 mL = 250 u *	1.25 mL = 125 u *	0.833 mL = 83.3 u	0.625 mL = 62.5 u	0.5 mL = 50 u
15 mg	3 mL = 300 u *	1.5 mL = 150 u *	1 mL = 100 u	0.75 mL = 75 u	0.6 mL = 60 u

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

Convert your own dose

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

1. Which vial?

Brand vial (Zepbound / Mounjaro)Compounded vial

Vial type

Single-doseMulti-dose

Strength on the vial label

Concentration: 5 mg ÷ 0.5 mL = 10 mg/mL. The label dose is 0.5 mL, the whole vial.

2. Convert

mg → unitsunits → mg

Dose in mg

3. Syringe (U-100)

0.3 mL · 30 units0.5 mL · 50 units1 mL · 100 units

Calculated dose

5 mg = 50 units(0.5 mL at 10 mg/mL)

Step 1. Concentrationmg/mL = mg in vial ÷ mL in vial
5 mg ÷ 0.5 mL = 10 mg/mL
Step 2. VolumemL = mg ÷ (mg/mL)
5 ÷ (5 ÷ 0.5) = 0.5 mL
Step 3. Units on a U-100 syringeunits = mL × 100
0.5 × 100 = 50 units

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.

Each dose in units

Or go back to the tirzepatide units to mg calculator.

Frequently asked questions

What is the tirzepatide dosing for weight loss in units?: With brand vials every dose is the same volume: 50 units (0.5 mL) from a single-dose vial or 60 units (0.6 mL) from a multi-dose vial, for every dose from 2.5 mg to 15 mg. With a compounded vial, units = mg ÷ (mg/mL) × 100, so it depends on the concentration on the label.
What is the tirzepatide dosing in mL?: 0.5 mL per dose from a brand single-dose vial and 0.6 mL per dose from a brand multi-dose vial. For a compounded vial, mL = mg ÷ (mg/mL): for example 5 mg at 10 mg/mL is 0.5 mL.
How long does each tirzepatide dose step last?: The labels start at 2.5 mg once weekly for 4 weeks, then increase in 2.5 mg steps after at least 4 weeks on the current dose. The maximum is 15 mg once weekly. The prescriber sets the actual schedule.
Which tirzepatide doses are maintenance doses?: The Zepbound label lists 5 mg, 10 mg or 15 mg as maintenance doses for weight reduction, and 10 mg or 15 mg for obstructive sleep apnea. 2.5 mg is only a starting dose.

Sources

Zepbound (tirzepatide) prescribing information (DailyMed, effective 2026-08-28)
Mounjaro (tirzepatide) prescribing information (DailyMed, effective 2026-08-27)

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