Tirzepatide dosing chart
Per the FDA labels for Zepbound and Mounjaro, tirzepatide is injected once a week, starting at 2.5 mg and raised in 2.5 mg steps after at least 4 weeks on each dose, up to a maximum of 15 mg. On a U-100 syringe, a vial mixed to 5 mg/mL (10 mg plus 2 mL) shows 2.5 mg as 50 units.[1,2]
These are the doses written on the FDA labels and used in a published trial, shown so you can read the units on a syringe. They are not a recommendation. Education only, not medical advice. PepDose sells no peptides.
What are the FDA label doses of tirzepatide?
- Per the Zepbound label: the starting dosage is 2.5 mg injected under the skin once a week for 4 weeks. The label says 2.5 mg is for starting treatment and is not a maintenance dosage.[1]
- Per the Zepbound label: after 4 weeks the dosage goes to 5 mg, and it can be raised in 2.5 mg steps after at least 4 weeks on the current dose. Maintenance dosages listed are 5 mg, 10 mg or 15 mg once a week for weight reduction and long-term maintenance, and 10 mg or 15 mg for obstructive sleep apnea. The maximum is 15 mg once a week.[1]
- Per the Mounjaro label (type 2 diabetes): the starting dosage is 2.5 mg once a week, raised in 2.5 mg steps after at least 4 weeks on the current dose if more glycemic control is needed. The maximum is 15 mg once a week in adults and 10 mg once a week in pediatric patients (10 years and older).[2]
- Used in the SURMOUNT-1 trial (2,539 adults with obesity, no diabetes, 72 weeks including a 20-week dose-escalation period): 5 mg, 10 mg or 15 mg once a week. Average weight change was −15.0%, −19.5% and −20.9%, versus −3.1% on placebo.[3]
- The approved Zepbound and Mounjaro products are supplied ready to use, as pens or vials (the labels list prefilled pens, KwikPen and single-dose vials). For those, the pharmacy label and the prescriber set the volume to draw; the chart below only shows the maths for a vial you mixed yourself.[1,2]
How many units is 2.5 mg of tirzepatide?
Units on a U-100 syringe = dose (mg) ÷ concentration (mg/mL) × 100. The concentration is the vial size divided by the water you added, so the same dose is a different number of units in each mix below.
| Dose | 10 mg vial + 2 mL5 mg/mL | 10 mg vial + 1 mL10 mg/mL | 15 mg vial + 3 mL5 mg/mL | 15 mg vial + 1.5 mL10 mg/mL | 20 mg vial + 2 mL10 mg/mL | 20 mg vial + 1 mL20 mg/mL | 30 mg vial + 3 mL10 mg/mL | 30 mg vial + 2 mL15 mg/mL | 60 mg vial + 3 mL20 mg/mL | 60 mg vial + 2 mL30 mg/mL |
|---|---|---|---|---|---|---|---|---|---|---|
| 2.5 mg | 50 units | 25 units | 50 units | 25 units | 25 units | 12.5 units | 25 units | 16.67 units | 12.5 units | 8.33 units |
How do you reconstitute a tirzepatide vial?
Add bacteriostatic water to the powder and note the strength. A 10 mg vial with 2 mL is 5 mg/mL. A 10 mg vial with 1 mL is 10 mg/mL. A 15 mg vial with 3 mL is 5 mg/mL. More water makes each unit weaker, which makes small doses easier to measure.
- Step 1
Clean
Wipe the vial stopper with an alcohol swab and let it dry.
- Step 2
Add water
Let the bacteriostatic water run slowly down the inside wall of the vial.
- Step 3
Swirl
Swirl or roll gently until clear. Don't shake.
- Step 4
Label and chill
Write the date and strength (mg/mL) on the vial and keep it in the fridge.
Do side effects change with the dose?
- Per the Zepbound label, the step-up schedule is there to reduce the risk of stomach and gut side effects.[1]
- In SURMOUNT-1, the most common side effects were gastrointestinal, mostly mild to moderate, and happened mainly while the dose was being raised. Side effects led 4.3% (5 mg), 7.1% (10 mg) and 6.2% (15 mg) of people to stop, versus 2.6% on placebo.[3]
- The Mounjaro label carries a boxed warning about thyroid C-cell tumors seen in rats, and says it is contraindicated with a personal or family history of medullary thyroid carcinoma or MEN 2.[2]
Research, side effects and legal status in full: Tirzepatide guide
Common questions about tirzepatide dosing
How many units is 2.5 mg of tirzepatide?
It depends on the concentration of your vial. Units on a U-100 syringe = mg ÷ (mg per mL) × 100. At 5 mg/mL (a 10 mg vial mixed with 2 mL), 2.5 mg is 50 units. At 10 mg/mL (a 30 mg vial mixed with 3 mL), it is 25 units. The 2.5 mg step is the starting dose on the FDA labels.
What are the tirzepatide doses on the FDA label?
Per the Zepbound label: the starting dosage is 2.5 mg once a week for 4 weeks, then 5 mg, with 2.5 mg steps after at least 4 weeks on each dose. Maintenance doses are 5, 10 or 15 mg once a week, and the maximum is 15 mg. The Mounjaro label uses the same 2.5 mg starting dose and 2.5 mg steps, with a 15 mg maximum in adults.
How long is each step on the label?
At least 4 weeks on the current dose before moving up by 2.5 mg, per both labels. The Zepbound label starts with 4 weeks at 2.5 mg.
Is a 5 mg tirzepatide dose the same number of units in every vial?
No. The units depend on how concentrated the vial is. 5 mg is 100 units at 5 mg/mL, 50 units at 10 mg/mL and 25 units at 20 mg/mL. Always work from the concentration on your own vial.
Is this chart for the Zepbound or Mounjaro pen?
No. The pens come ready to use and are dosed by clicking or by the pharmacy label. This chart is syringe maths for a vial mixed from powder. Powder is not the approved product and is not checked by the FDA.
Is this medical advice?
No. The doses are quoted from the FDA labels and a published trial so you can read the units on a syringe. They are not a recommendation. Ask a licensed clinician about dosing. PepDose sells no peptides.
Sources
Last reviewed Nov 7, 2026. Every dose and result above is copied from these sources.
- 1.Zepbound (tirzepatide) injection: DailyMed label
FDA via DailyMed. Zepbound (tirzepatide) prescribing information, Eli Lilly, section 2 Dosage and Administration (label dated 2026-08-28; opened 2026-11-07) · FDA - 2.Mounjaro (tirzepatide) injection: DailyMed label
FDA via DailyMed. Mounjaro (tirzepatide) prescribing information, Eli Lilly, boxed warning and section 2 (label dated 2026-08-27; opened 2026-11-07) · FDA - 3.Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1)
Jastreboff AM et al. N Engl J Med 2022;387:205-216 · Human trial
Education only, not medical advice. PepDose sells no peptides.