Tirzepatide units chart: how many units is 2.5, 5, 10 or 15 mg?

"How many units is 5 mg of tirzepatide" has no one answer. Units measure volume, and the volume that holds 5 mg depends on how much water went into the vial. Two common guides mix the same 10 mg vial differently: one adds 1 mL (10 mg per mL), the other adds 2 mL (5 mg per mL). The same dose then takes twice as many units from the second vial.

So start with two numbers off your own vial: the mg on the label and the mL of water you added. Find that pair below, or put it in the reconstitution calculator for any dose. The method behind every line is in mg to units conversion.

Branded Zepbound single-dose pens and vials skip all of this: each holds one fixed dose, so there are no units to count. Zepbound's multi-dose vial and KwikPen hold four fixed doses each, and their own instructions say how to measure them. This chart is for powder vials you mix yourself.

The rows follow the label ladder: 2.5 mg once a week to start, then up 2.5 mg at a time after at least 4 weeks on each step, to a maximum of 15 mg. That gives 2.5, 5, 7.5, 10, 12.5 and 15 mg. The 2.5 mg step is a starter dose; the Zepbound label lists 5, 10 or 15 mg as maintenance.

If you have a tested amount for your vial, use it in the calculator instead of the label mg. See the tirzepatide page for the full dosing picture.

The two common ways to mix a 10 mg vial are 1 mL and 2 mL of bacteriostatic water. A vial only holds 10 mg, so higher doses are not listed.

10 mg vial + 1 mL water (10 mg/mL)

• 2.5 mg: 25 units (0.25 mL)
• 5 mg: 50 units (0.5 mL)
• 7.5 mg: 75 units (0.75 mL)
• 10 mg: 100 units (1 mL)

10 mg vial + 2 mL water (5 mg/mL)

• 2.5 mg: 50 units (0.5 mL)
• 5 mg: 100 units (1 mL)
• 7.5 mg: 150 units (1.5 mL) more than one full 1 mL syringe
• 10 mg: 200 units (2 mL) more than one full 1 mL syringe

With 2 mL, anything past 5 mg needs more than a full 1 mL syringe. With 1 mL, every dose up to 10 mg fits in one syringe.

The usual mix for a 15 mg vial is 1.5 mL, which gives the same strength as the common 10 mg mix.

15 mg vial + 1.5 mL water (10 mg/mL)

• 2.5 mg: 25 units (0.25 mL)
• 5 mg: 50 units (0.5 mL)
• 7.5 mg: 75 units (0.75 mL)
• 10 mg: 100 units (1 mL)
• 12.5 mg: 125 units (1.25 mL) more than one full 1 mL syringe
• 15 mg: 150 units (1.5 mL) more than one full 1 mL syringe

Guides list three ways to mix a 30 mg vial. 3 mL is the standard. 2 mL makes a stronger mix that keeps 15 mg inside one 1 mL syringe. 6 mL makes a weak mix that some use for small doses.

30 mg vial + 3 mL water (10 mg/mL)

• 2.5 mg: 25 units (0.25 mL)
• 5 mg: 50 units (0.5 mL)
• 7.5 mg: 75 units (0.75 mL)
• 10 mg: 100 units (1 mL)
• 12.5 mg: 125 units (1.25 mL) more than one full 1 mL syringe
• 15 mg: 150 units (1.5 mL) more than one full 1 mL syringe

30 mg vial + 2 mL water (15 mg/mL)

• 2.5 mg: 16.7 units (0.167 mL)
• 5 mg: 33.3 units (0.333 mL)
• 7.5 mg: 50 units (0.5 mL)
• 10 mg: 66.7 units (0.667 mL)
• 12.5 mg: 83.3 units (0.833 mL)
• 15 mg: 100 units (1 mL)

30 mg vial + 6 mL water (5 mg/mL)

• 2.5 mg: 50 units (0.5 mL)
• 5 mg: 100 units (1 mL)
• 7.5 mg: 150 units (1.5 mL) more than one full 1 mL syringe
• 10 mg: 200 units (2 mL) more than one full 1 mL syringe
• 12.5 mg: 250 units (2.5 mL) more than one full 1 mL syringe
• 15 mg: 300 units (3 mL) more than one full 1 mL syringe

At 2 mL the low doses land between syringe lines. A 1 mL syringe has a line every 2 units; a 0.3 mL or 0.5 mL syringe has one every unit, which gets 16.7 or 33.3 units much closer to a mark. At 6 mL the high doses take several mL, more than most people want in one shot.

A 60 mg vial is usually mixed with 6 mL, again giving the common 10 mg per mL strength.

60 mg vial + 6 mL water (10 mg/mL)

• 2.5 mg: 25 units (0.25 mL)
• 5 mg: 50 units (0.5 mL)
• 7.5 mg: 75 units (0.75 mL)
• 10 mg: 100 units (1 mL)
• 12.5 mg: 125 units (1.25 mL) more than one full 1 mL syringe
• 15 mg: 150 units (1.5 mL) more than one full 1 mL syringe

Most guides aim for 10 mg per mL, which works out to 1 mL of water for every 10 mg of powder:

• 10 mg vial: 1 mL (some use 2 mL)
• 15 mg vial: 1.5 mL
• 30 mg vial: 3 mL (some use 2 mL or 6 mL)
• 60 mg vial: 6 mL

The 10 mg per mL mix keeps the math easy and fits doses up to 10 mg in one syringe. More water makes small doses easier to measure and big doses bulkier. Less water does the opposite. Pick a volume, write it on the vial, and use the matching chart above.

Added too much water by mistake? The tirzepatide is fine. The strength changed, so recalculate your units for the new volume in the calculator.

The steps are the same for a 10, 30 or 60 mg vial. Only the water volume changes.

1. Let the vial reach room temperature. Swab both stoppers with alcohol and let them dry.
2. Measure the water with a 3 mL syringe. An insulin syringe tops out at 1 mL and turns 3 or 6 mL into a lot of separate draws.
3. Push the water slowly down the inside wall of the vial, not onto the powder.
4. Roll or swirl gently until it dissolves. Never shake.
5. Check that it is clear. Label the vial with the date and the strength, for example 10 mg per mL.
6. Keep it in the fridge at 2 to 8 C and use it within 28 days.

The full walkthrough, with sterile technique, is in how to reconstitute peptides.

It depends on the mix, again. Here is what 30 units holds in each setup above.

10 mg vial + 1 mL water (10 mg/mL)

• 3 mg: 30 units (0.3 mL)

15 mg vial + 1.5 mL water (10 mg/mL)

• 3 mg: 30 units (0.3 mL)

30 mg vial + 3 mL water (10 mg/mL)

• 3 mg: 30 units (0.3 mL)

60 mg vial + 6 mL water (10 mg/mL)

• 3 mg: 30 units (0.3 mL)

10 mg vial + 2 mL water (5 mg/mL)

• 1.5 mg: 30 units (0.3 mL)

30 mg vial + 6 mL water (5 mg/mL)

• 1.5 mg: 30 units (0.3 mL)

30 mg vial + 2 mL water (15 mg/mL)

• 4.5 mg: 30 units (0.3 mL)

The same 30 units is anywhere from 1.5 mg to 4.5 mg depending on the vial. That spread is exactly why a units number from someone else's vial means nothing for yours.

A standard U-100 insulin syringe holds 100 units, which is 1 mL. At 10 mg per mL, 12.5 mg and 15 mg are over that, so guides split them into two draws, for example a full syringe plus a second smaller one.

The other option is a stronger mix next time. A 30 mg vial with 2 mL puts 15 mg at exactly 100 units, one full syringe.

• Copying units from someone else. "I take 50 units" only means something next to a vial size and a water volume.
• Keeping the old units after switching vials. A new vial size or a new water volume changes the strength. Recalculate before the first shot.
• Reading units as mg or IU. Syringe units are volume: 100 units is 1 mL. They are not a dose by themselves and not IU.
• Using an oversized syringe for a small dose. FDA has collected reports of people taking 5 to 20 times their intended dose of compounded semaglutide, with unit and mL mix-ups and oversized syringes among the causes it named.

Write the strength on the vial the day you mix it, and you avoid most of this.