This is the label schedule, not a plan for youThe doses below are quoted from the FDA prescribing information for Zepbound and Mounjaro.[1][2] Your prescriber decides when, and whether, to move up a step.
Zepbound doses: the escalation ladder
The Zepbound label: “The recommended starting dosage of ZEPBOUND for all indications is 2.5 mg injected subcutaneously once weekly for 4 weeks.”[1] After those 4 weeks the dose goes up to 5 mg, and from there it “may be increased in 2.5 mg increments, after at least 4 weeks on the current dose.”[1] Mounjaro uses the same 2.5 mg start and 2.5 mg steps.[2] The bars show the earliest week each step can begin.
- 2.5 mgWeeks 1–4 · starting dose
- 5 mgFrom week 5 at the earliest
- 7.5 mgFrom week 9 at the earliest
- 10 mgFrom week 13 at the earliest
- 12.5 mgFrom week 17 at the earliest
- 15 mgFrom week 21 at the earliest · maximum
Starting doseEscalation stepListed Zepbound maintenance dose for weight
Lilly states that the schedule is the same whichever device is used: single-dose pen, vial or KwikPen.[4]
Zepbound dose schedule, week by week
On the fastest schedule the label allows, 2.5 mg runs weeks 1–4, 5 mg weeks 5–8, and each later step starts 4 weeks after the last. Many people stay on a step longer, or stop at a lower dose.
| Weeks | Weekly dose | mg in the step | Cumulative mg |
|---|---|---|---|
| 1–4 | 2.5 mg | 10 mg | 10 mg |
| 5–8 | 5 mg | 20 mg | 30 mg |
| 9–12 | 7.5 mg | 30 mg | 60 mg |
| 13–16 | 10 mg | 40 mg | 100 mg |
| 17–20 | 12.5 mg | 50 mg | 150 mg |
| 21 onward | 15 mg | 15 mg per week | 150 mg before week 21 |
Arithmetic: each 4-week step uses four doses, so the climb from 2.5 to 12.5 mg uses 150 mg of tirzepatide before the first 15 mg dose. In the trials, escalation took “up to 20 weeks”.[1]
Zepbound maintenance dose by use
Zepbound lists fixed maintenance doses (5, 10 or 15 mg for weight; 10 or 15 mg for sleep apnea), while Mounjaro has none. The Mounjaro steps are set out on the Mounjaro dosage chart.[1][2]
| Product and use | Start | Maintenance | Maximum |
|---|---|---|---|
| Zepbound: weight reduction and maintenance (adults) | 2.5 mg weekly | 5 mg, 10 mg or 15 mg | 15 mg weekly |
| Zepbound: moderate to severe obstructive sleep apnea with obesity (adults) | 2.5 mg weekly | 10 mg or 15 mg | 15 mg weekly |
| Mounjaro: type 2 diabetes, adults | 2.5 mg weekly | No fixed list; increase by 2.5 mg only if more glucose control is needed. Since August 2026, 2.5 mg may be continued. | 15 mg weekly |
| Mounjaro: type 2 diabetes, age 10 and older | 2.5 mg weekly | Same stepwise approach | 10 mg weekly |
- Zepbound, 2.5 mg: “The 2.5 mg dosage is for treatment initiation and is not approved as a maintenance dosage.”[1]
- Mounjaro, 2.5 mg: an August 2026 label update says the 2.5 mg dose can be used for ongoing glycemic control. That change applies to Mounjaro only.[3][2]
- Mounjaro in children: approved for type 2 diabetes from age 10, with a maximum of 10 mg once weekly.[2]
In SURMOUNT-1, 5, 10 and 15 mg all produced more weight loss than placebo, with larger average losses at higher doses.[5] For obstructive sleep apnea, the trials used the maximum tolerated dose of 10 or 15 mg.[6] See Zepbound for sleep apnea.
When to increase the Zepbound dose
The label allows a dose increase only after at least 4 weeks on the current dose: 2.5 mg always moves to 5 mg after 4 weeks, and every later step of 2.5 mg is optional.[1] It tells prescribers to “consider treatment response and tolerability when selecting the maintenance dosage,” so staying on a dose that works and is tolerated is within the label.[1]
Zepbound dosage increases when a step is not tolerated
The Zepbound label: “Consider treatment response and tolerability when selecting the maintenance dosage. If patients do not tolerate a maintenance dosage, consider a lower maintenance dosage.”[1] It also says the gradual escalation is there to reduce the risk of stomach side effects, and that “the majority of nausea, vomiting, and/or diarrhea events occurred during dose escalation and decreased over time.”[1] See side effects by dose.
Dose adjustments for kidneys, liver and age
The Zepbound label recommends no dose change for kidney or liver impairment, including end-stage kidney disease, because tirzepatide levels were unchanged in those studies.[1] About 9% of people in the weight trials were 65 or older, with no overall differences in safety or effect.[1] Zepbound's safety in children has not been established; Mounjaro is approved from age 10 with a 10 mg maximum.[1][2]
How long is Zepbound taken?
Zepbound is labeled for long-term use: it is indicated to “reduce excess body weight and maintain weight reduction long term.”[1] In SURMOUNT-4, people who stopped after 36 weeks regained 14.0% of body weight within a year, while those who continued kept losing.[7]
Doses per pen, vial and KwikPen
| Presentation | Doses | Volume per dose | Packs |
|---|---|---|---|
| Single-dose pen | 1 | 0.5 mL | Cartons of 4 pens |
| Single-dose vial | 1 | 0.5 mL | Cartons of 1 or 4 vials |
| KwikPen | 4 | 0.6 mL | 1 pen = 4 weeks |
| Multi-dose vial | 4 | 0.6 mL | 1 vial = 4 weeks |
Every presentation comes in all six strengths, so each dose step needs a new pen or vial.[1]
Measuring each step
With the approved products every dose is a fixed volume:[1]
- Single-dose pen or vial: one dose in 0.5 mL. With a vial, the whole contents are drawn and injected.
- Multi-dose vial: four doses of 0.6 mL. Each vial holds one strength, so moving up a step means a new vial.
- KwikPen: four fixed 0.6 mL doses selected on the dial.
Unit arithmetic comes in only when a solution's strength does not match a fixed dose, such as a compounded vial. For that, use the calculator or the units to mg chart.
Each dose in units
Every step in the table links to its section on how many units is 2.5 mg of tirzepatide, which covers all six doses. Related pages:
- Missed a dose?The 4-day rule on a calendar
- Tirzepatide half-lifeWhy each step lasts 4 weeks
- Side effects by doseLabel tables for 5, 10 and 15 mg
- Sleep apnea dose10 or 15 mg maintenance
Frequently asked questions
What is the starting dose of tirzepatide?
What are the Zepbound dosage levels?
2.5, 5, 7.5, 10, 12.5 and 15 mg once weekly. 2.5 mg is the starting dose; 5, 10 and 15 mg are the listed maintenance doses for weight.[1]
How fast can tirzepatide be increased?
What is the maximum dose of tirzepatide?
Do I have to go up to 15 mg?
What dose of Zepbound is most effective?
In SURMOUNT-1, average weight loss was largest on 15 mg (−20.9%), then 10 mg (−19.5%) and 5 mg (−15.0%), versus −3.1% on placebo.[5]
Do I need a lower dose for kidney problems?
The Zepbound label recommends no dose adjustment for kidney or liver impairment.[1]
Is the Zepbound vial schedule different from the pen?
No. The doses and the 4-week steps are the same for the single-dose pen, the vials and the KwikPen.[4]
Sources
- Zepbound (tirzepatide) injection: prescribing information, Medication Guide and Instructions for Use
- Mounjaro (tirzepatide) injection: prescribing information and Instructions for Use
- Mounjaro supplement approval letter S-044/S-045 (cardiovascular indication; 2.5 mg for ongoing glycemic control)
- Zepbound HCP dosage page and FAQ
- Jastreboff AM et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1)
- Malhotra A et al. Tirzepatide for the treatment of obstructive sleep apnea and obesity (SURMOUNT-OSA)
- Aronne LJ et al. Continued treatment with tirzepatide for maintenance of weight reduction (SURMOUNT-4)