Is 15 mg of tirzepatide the same as 300 units?

Only at 5 mg/mL. Units measure volume, not drug, so the same 15 mg is 187.5 units at 8 mg/mL, 150 units at 10 mg/mL, 100 units at 15 mg/mL and 75 units at 20 mg/mL on a U-100 insulin syringe. Check the strength printed on your vial label before you count units. Not personalized advice; confirm your dose, in mg and in units, with your prescriber or the dispensing pharmacy.

How many mL is 15 mg of tirzepatide?

15 mg ÷ the vial strength = mL: 3 mL at 5 mg/mL, 1.875 mL at 8 mg/mL, 1.5 mL at 10 mg/mL, 1 mL at 15 mg/mL, 0.75 mL at 20 mg/mL. On a U-100 syringe, every 0.01 mL is 1 unit.

Can 15 mg of tirzepatide be measured on an insulin syringe?

At 5 mg/mL it is 300 units, which needs more than one 1 mL syringe; at 8 mg/mL it is 187.5 units, which needs more than one 1 mL syringe; at 10 mg/mL it is 150 units, which needs more than one 1 mL syringe; at 15 mg/mL it is 100 units, which fits a 1 mL (100 units) syringe; at 20 mg/mL it is 75 units, which fits a 1 mL (100 units) syringe. Each of these lands on a printed mark of a half-unit scale.

How Many Units Is 15 mg of Tirzepatide? U-100 Chart

Short answer: 15 mg of tirzepatide is 300 units on a U-100 syringe at 5 mg/mL, 187.5 units at 8 mg/mL, 150 units at 10 mg/mL, 100 units at 15 mg/mL and 75 units at 20 mg/mL. In volume that is 3 mL at 5 mg/mL, 1.875 mL at 8 mg/mL, 1.5 mL at 10 mg/mL, 1 mL at 15 mg/mL and 0.75 mL at 20 mg/mL. Compounded products are not FDA approved; check the strength on your vial label, because the units are only right for that strength.

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 15 mg at each vial strength?

Each row converts 15 mg at one compounded tirzepatide strength 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.

15 mg of tirzepatide, U-100 insulin syringe. Click a strength for every dose at that strength.
Vial strength	Volume	U-100 units	Smallest syringe that holds it
5 mg/mL	3 mL	300 units	More than one 1 mL syringe
8 mg/mL	1.875 mL	187.5 units	More than one 1 mL syringe
10 mg/mL	1.5 mL	150 units	More than one 1 mL syringe
15 mg/mL	1 mL	100 units	1 mL (100 units)
20 mg/mL	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. See U-40 vs U-100 syringes and how to read the marks.

How do you check the math?

Divide the dose by the strength to get mL, then multiply by 100 for U-100 units. To check, run it backwards: units ÷ 100 × mg/mL should give back 15 mg.

5 mg/mL. 15 mg ÷ 5 mg/mL = 3 mL × 100 = 300 units; check: 300 ÷ 100 × 5 = 15 mg
8 mg/mL. 15 mg ÷ 8 mg/mL = 1.875 mL × 100 = 187.5 units; check: 187.5 ÷ 100 × 8 = 15 mg
10 mg/mL. 15 mg ÷ 10 mg/mL = 1.5 mL × 100 = 150 units; check: 150 ÷ 100 × 10 = 15 mg
15 mg/mL. 15 mg ÷ 15 mg/mL = 1 mL × 100 = 100 units; check: 100 ÷ 100 × 15 = 15 mg
20 mg/mL. 15 mg ÷ 20 mg/mL = 0.75 mL × 100 = 75 units; check: 75 ÷ 100 × 20 = 15 mg

If the units on your instructions do not match this math for the strength on your vial, ask the prescriber or pharmacy before injecting.

Where is 15 mg in the label schedule?

In the Mounjaro label, 15 mg is dose step 6 of 6. The label schedule lists it as Maximum: 15 mg once weekly in adults. (Mounjaro label)

In the Zepbound label, 15 mg is dose step 6 of 6. The label schedule lists it as 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. (Zepbound label)

Compounded tirzepatide has no FDA label of its own. For reference, these are the schedules in the FDA labels that name 15 mg, with its rows highlighted.

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.

Full schedules: Mounjaro dosing schedule · Zepbound dosing schedule

Other tirzepatide doses

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2.5 mg · 5 mg · 7.5 mg · 10 mg · 12.5 mg · All tirzepatide doses and 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 15 mg of tirzepatide?