Tirzepatide dosage chart: mg, mL and units

Tirzepatide dose schedule on the label

The tirzepatide label schedule starts at 2.5 mg injected once a week for 4 weeks. The dose then goes up in 2.5 mg steps, with at least 4 weeks on each dose, up to a maximum of 15 mg once a week^1–2. Going up slowly is meant to lower the chance of stomach side effects like nausea¹.

The Zepbound label says the 2.5 mg dose is only for starting, not for staying on. Its maintenance doses are 5 mg, 10 mg or 15 mg a week for weight reduction, and 10 mg or 15 mg for obstructive sleep apnea². If a maintenance dose isn't tolerated, the Zepbound label says a lower maintenance dose can be considered². The Mounjaro label says to raise the dose if more blood sugar control is needed. Its maximum is 15 mg for adults and 10 mg for children aged 10 and older¹.

Both labels say to inject once a week, at any time of day, with or without food. It goes under the skin of the belly, thigh or back of the upper arm. Change the spot each week^1–2.

FDA has had reports of side effects in people prescribed compounded semaglutide or tirzepatide at doses beyond the approved label. That means a bigger single dose, doses more often than weekly, or going up faster than the label schedule. Some people needed medical care for symptoms like nausea, vomiting, diarrhea, stomach pain and constipation³.

Mounjaro and Zepbound pen doses in mL

Mounjaro and Zepbound pens give a set tirzepatide dose, so there are no units to measure. The single-dose pen holds one dose in 0.5 mL. The KwikPen holds 4 weekly doses of 0.6 mL each, 2.4 mL in total^1–2.

• Single-dose pen: one pen per week, in 2.5, 5, 7.5, 10, 12.5 or 15 mg^1–2.
• KwikPen: one pen covers 4 weekly doses. Each pen is one strength, so a dose change means a new pen. The pen stops you dialing a full dose after the 4th one. The instructions say not to inject the leftover medicine and not to move it into a syringe⁵.

If you move between a pen and a vial, the mg dose can stay the same while the mL changes. A 5 mg dose is 0.5 mL from a single-dose pen or vial, but 0.6 mL from a KwikPen or multi-dose vial^1–2.

How many units is 2.5 mg of tirzepatide?

At 10 mg/mL, 2.5 mg of tirzepatide is 25 units on a U-100 insulin syringe (0.25 mL). The number changes with your vial's strength: at 5 mg/mL it's 50 units, and at 15 mg/mL it's about 16.7 units.

On a U-100 insulin syringe, 100 units equal 1 mL, so 1 unit is 0.01 mL. A unit here is a mark on the syringe, not an amount of tirzepatide.

1. 1
   Find the strength on your vial label

   Look for mg/mL, for example "10 mg/mL". If it only says a total, like 20 mg in 2 mL, divide: 20 ÷ 2 = 10 mg/mL.
2. 2
   Divide your dose by the strength

   This gives mL. For 2.5 mg at 10 mg/mL: 2.5 ÷ 10 = 0.25 mL.
3. 3
   Multiply by 100

   This gives units on a U-100 syringe. 0.25 mL × 100 = 25 units.

How many mg of tirzepatide is 10, 20 or 50 units?

At 10 mg/mL, 10 units of tirzepatide is 1 mg, 20 units is 2 mg and 50 units is 5 mg. For any vial, multiply the units by the strength in mg/mL, then divide by 100.

Use this to check that the units on a pharmacy label match the mg your prescriber wrote.

Zepbound vial dose in mL and units

A Zepbound single-dose vial holds one dose of tirzepatide in 0.5 mL, at every strength from 2.5 mg to 15 mg². On a U-100 insulin syringe, 0.5 mL is the 50-unit line. The multi-dose vial holds 4 weekly doses in 2.4 mL, and each dose is 0.6 mL, or 60 units².

With brand vials, the amount you draw stays the same when your dose goes up. Only the strength printed on the vial changes. Mounjaro comes in the same vial sizes¹.

The Zepbound instructions give the dose in mL: draw to the 0.5 mL line for a single-dose vial, or the 0.6 mL line for a multi-dose vial². The label says to use a syringe that can measure that amount, such as a 1 mL syringe. Use a new syringe and needle every time². Use the syringe your prescriber or pharmacist recommends.

• Single-dose vial: use it once and throw it away, even if some medicine is left².
• Multi-dose vial: throw it away after 4 weekly doses, 30 days after first use, or after 30 days in total at room temperature, even if medicine is left².

What if you miss a tirzepatide dose?

Take a missed tirzepatide dose as soon as you can, as long as it's within 4 days (96 hours). That's the rule on both the Mounjaro and Zepbound labels. If more than 4 days have passed, skip it and take the next one on your usual day^1–2.

You can move your injection day, as long as there are at least 3 days (72 hours) between two doses^1–2. For worked examples and other GLP-1 medicines, see our missed GLP-1 dose guide.

Mounjaro pen doses in the UK

In the UK, tirzepatide comes as the Mounjaro KwikPen. Each pen holds 4 fixed doses of 0.6 mL, at strengths from 2.5 mg to 15 mg per dose⁴. You turn the knob until it stops, so there are no units or mL to work out.

The UK dose steps match the US: 2.5 mg for 4 weeks, then 5 mg, then 2.5 mg steps at least 4 weeks apart, up to 15 mg⁴. Read Mounjaro pen doses in the UK for pen sizes, leftover liquid and why the pen isn't made for partial doses.