How many units is 2.5 mg of tirzepatide at 20 mg/mL?

2.5 mg ÷ 20 mg/mL = 0.125 mL, which is 12.5 units on a U-100 insulin syringe (1 mL = 100 units). At a different strength the same mg is a different number of units, so check the strength printed on your vial. Not personalized advice; confirm your dose, in mg and in units, with your prescriber or the dispensing pharmacy.

How many units is each tirzepatide label dose at 20 mg/mL?

2.5 mg = 12.5 units; 5 mg = 25 units; 7.5 mg = 37.5 units; 10 mg = 50 units; 12.5 mg = 62.5 units; 15 mg = 75 units. These are the dose steps named in the Mounjaro and Zepbound labels, converted at 20 mg/mL on a U-100 syringe. Doses over 100 units need more than one 1 mL syringe.

How many doses are in a 2 mL vial of tirzepatide at 20 mg/mL?

A 2 mL vial at 20 mg/mL holds 40 mg in total. That is 16 doses of 2.5 mg, 8 doses of 5 mg, 5 doses of 7.5 mg, 4 doses of 10 mg. In practice a little is lost to syringe dead space and the last drops in the vial.

Which syringe is used to measure tirzepatide in units?

Unit instructions for compounded GLP-1 vials assume a U-100 insulin syringe, where 1 unit is 0.01 mL. A U-40 syringe, used for some veterinary insulin, has different markings and would give 2.5 times the volume at the same number. FDA has asked prescribers and compounders to give patients a syringe sized for the dose and to show them how to measure it.

Tirzepatide 20 mg/mL: Units per Dose Chart

Q: Is compounded tirzepatide the same as Mounjaro and Zepbound?

No. Mounjaro and Zepbound are FDA-approved products dosed in mg from pens (and, for some, labeled vials). Compounded tirzepatide is not FDA approved, and FDA does not review compounded drugs for safety, effectiveness or quality before they are marketed. FDA has received reports of dosing errors with compounded semaglutide in multi-dose vials, many involving confusion between mg, mL and units.

Short answer: At 20 mg/mL, 2.5 mg of tirzepatide is 0.125 mL, which is 12.5 units on a U-100 insulin syringe. Every 1 mg is 5 units. The units only hold for a vial labeled 20 mg/mL; at another strength the same mg is a different number of units.

Compounded vs FDA-approved. Compounded tirzepatide is not FDA approved, and FDA does not review compounded drugs for safety, effectiveness or quality before they are sold (FDA). Mounjaro and Zepbound single-dose pens each hold one fixed dose, and the KwikPen is set to its labeled dose, so the dose is chosen in mg and there are no syringe units to work out. The labeled single-dose vials are one dose each, and the labeled multi-dose vial gives four doses of 0.6 mL; follow the instructions for use that come with them, not a compounded units chart.

How many units is each label dose at 20 mg/mL?

The rows below are every dose step named in the Mounjaro and Zepbound labels, converted at 20 mg/mL for a U-100 insulin syringe (1 mL = 100 units). Not personalized advice; confirm your dose, in mg and in units, with your prescriber or the dispensing pharmacy.

Tirzepatide 20 mg/mL, U-100 insulin syringe.
Dose	Named in label	Volume	U-100 units	Smallest syringe that holds it
2.5 mg	Mounjaro, Zepbound: start	0.125 mL	12.5 units	0.3 mL (30 units)
5 mg	Mounjaro, Zepbound	0.25 mL	25 units	0.3 mL (30 units)
7.5 mg	Mounjaro, Zepbound	0.375 mL	37.5 units	0.5 mL (50 units)
10 mg	Mounjaro, Zepbound	0.5 mL	50 units	0.5 mL (50 units)
12.5 mg	Mounjaro, Zepbound	0.625 mL	62.5 units	1 mL (100 units)
15 mg	Mounjaro, Zepbound: max	0.75 mL	75 units	1 mL (100 units)

"Between marks" means the volume does not land on a printed line, even on a 0.3 mL syringe with half-unit markings. A 1 mL syringe is usually marked every 2 units, so small doses are easier to read on a 0.3 mL or 0.5 mL barrel. See U-40 vs U-100 syringes and how to read the marks.

How many doses are in a vial at 20 mg/mL?

The number of doses depends on how much liquid is in the vial, not only the strength. Check the volume on your vial label, then read across. Counts are whole doses; dead space in the syringe and the last drops in the vial usually take a little more.

Whole doses per vial at 20 mg/mL. Vial volumes are examples.
Dose	1 mL vial (20 mg)	2 mL vial (40 mg)	3 mL vial (60 mg)	4 mL vial (80 mg)
2.5 mg	8	16	24	32
5 mg	4	8	12	16
7.5 mg	2	5	8	10
10 mg	2	4	6	8
12.5 mg	1	3	4	6
15 mg	1	2	4	5

How do you convert mg to units yourself?

Volume. dose in mg ÷ 20 mg/mL = mL
Units. mL × 100 = units on a U-100 syringe
Check. units ÷ 100 × 20 = mg, which should match the dose on your prescription.

Example: 2.5 mg ÷ 20 mg/mL = 0.125 mL = 12.5 units. If the units on your instructions do not match this math for the strength on your vial, ask the prescriber or pharmacy before injecting.

What is the FDA label dosing schedule for tirzepatide?

Compounded tirzepatide has no FDA label of its own. For reference, these are the schedules in the FDA labels for Mounjaro and Zepbound, which are dosed in mg.

Zepbound (FDA label, section 2)

Label schedule, quoted from the prescribing information. Your prescriber sets your own schedule.
When	Label dose
Weeks 1 to 4	2.5 mg once weekly (for starting treatment only)
Week 5	5 mg once weekly
Further steps	Increase by 2.5 mg after at least 4 weeks on the current dose
Maintenance	5 mg, 10 mg or 15 mg once weekly for weight reduction; 10 mg or 15 mg for obstructive sleep apnea
Maximum	15 mg once weekly

The label states that 2.5 mg is for starting treatment and is not an approved maintenance dose.

Mounjaro (FDA label, section 2)

Label schedule, quoted from the prescribing information. Your prescriber sets your own schedule.
When	Label dose
Start	2.5 mg once weekly
Further steps	If more glycemic control is needed, increase by 2.5 mg after at least 4 weeks on the current dose
Maximum	15 mg once weekly in adults

For pediatric patients 10 years and older the Mounjaro label sets a lower maximum of 10 mg once weekly.

Other tirzepatide strengths

Tirzepatide 5 mg/mL · Tirzepatide 8 mg/mL · Tirzepatide 10 mg/mL · Tirzepatide 15 mg/mL · All tirzepatide strengths in one grid

Mixing a powder vial instead? The tirzepatide reconstitution guide and the free reconstitution calculator handle vials you add water to.

How many units is tirzepatide at 20 mg/mL?