The highest dose of tirzepatide
What the labels allow, how long it takes to get there, and what the trials found at the top dose.
Key facts
- The maximum is 15 mg once a week for Zepbound and for Mounjaro in adults.
- For children aged 10 and over on Mounjaro, the maximum is 10 mg.
- Reaching 15 mg takes at least 20 weeks: five 4-week steps from 2.5 mg.
- In SURMOUNT-1, 15 mg gave 20.9% average weight loss over 72 weeks, against 19.5% at 10 mg.
The maximum dose on each label
| Product | Who | Maximum |
|---|---|---|
| Zepbound | Adults, weight management or sleep apnoea | 15 mg / week |
| Mounjaro | Adults with type 2 diabetes | 15 mg / week |
| Mounjaro | Children aged 10+ with type 2 diabetes | 10 mg / week |
15 mg is a maintenance dose on the Zepbound label, for weight management and for sleep apnoea. It is not the target for everyone: the label also lists 5 and 10 mg, and says a lower maintenance dose can be considered if a dose is not tolerated.
How long it takes to reach 15 mg
Every course starts at 2.5 mg for 4 weeks and rises by 2.5 mg with at least 4 weeks on each dose. That is five steps, so the earliest anyone reaches 15 mg is week 21. Many people take longer, staying on a dose while side effects settle; there is no requirement to move up on schedule.
What 15 mg adds over 10 mg
In SURMOUNT-1, adults with obesity and no diabetes lost, on average over 72 weeks:
| Dose | Average weight loss | Lost 20% or more |
|---|---|---|
| 10 mg | 19.5% | 50% |
| 15 mg | 20.9% | 57% |
| Placebo | 3.1% | 3% |
The step from 10 to 15 mg added 1.4 percentage points on average1. In people with type 2 diabetes (SURMOUNT-2) the gap was similar: 12.8% at 10 mg and 14.7% at 15 mg2. Stomach side effects were already common at 10 mg and did not fall at 15 mg: nausea 29% and 28%, vomiting 11% and 13% on the Zepbound label3.
15 mg in units
| Source | Volume | U-100 syringe |
|---|---|---|
| Single-dose vial (30 mg/mL) | 0.5 mL | 50 units |
| Multi-dose vial (25 mg/mL) | 0.6 mL | 60 units |
| Compounded, 10 mg/mL | 1.5 mL | over 1 mL |
| Compounded, 20 mg/mL | 0.75 mL | 75 units |
At low compounded concentrations 15 mg does not fit a 1 mL syringe. Use a larger syringe rather than two draws, and see the 15 mg page for every vial strength.
Doses above 15 mg
Getting tirzepatide prescribed
Frequently asked questions
What is the highest dose of Mounjaro?
15 mg once a week in adults and 10 mg in children aged 10 and over with type 2 diabetes.
What is the highest dose of Zepbound?
15 mg once a week, which is also one of its maintenance doses for weight management and sleep apnoea.
How long does it take to reach 15 mg?
At least 20 weeks: 2.5 mg for 4 weeks, then four more 4-week steps at 5, 7.5, 10 and 12.5 mg.
Is 15 mg much better than 10 mg?
In SURMOUNT-1, average weight loss was 20.9% at 15 mg against 19.5% at 10 mg over 72 weeks; 57% and 50% of people lost 20% or more.
Scientific references
- Jastreboff AM et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). N Engl J Med 2022;387:205-216.
- Garvey WT et al. Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes (SURMOUNT-2). Lancet 2023.
- Eli Lilly and Company. ZEPBOUND (tirzepatide) prescribing information. DailyMed, 2026.
- Eli Lilly and Company. MOUNJARO (tirzepatide) prescribing information. DailyMed, 2026.