Tirzepatide is labelled at six once-weekly strengths: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg and 15 mg. Treatment starts at 2.5 mg for four weeks, then moves up in 2.5 mg increments after at least four weeks on the current dose, which makes 20 weeks the shortest route from a first injection to the 15 mg ceiling.
Only three of those six strengths have a weight-loss figure attached to them. SURMOUNT-1 randomly assigned 2539 adults with obesity, or overweight with a weight-related complication and no diabetes, to tirzepatide 5 mg, 10 mg, 15 mg or placebo for 72 weeks, and reported mean weight changes of -15.0%, -19.5% and -20.9% against -3.1% on placebo (PMID 35658024). The chart below separates what the label permits from what a trial actually measured.
- Six labelled strengths, one starting dose: 2.5 mg for the first four weeks, then 2.5 mg increments no sooner than every four weeks.
- 5 mg, 10 mg and 15 mg are the maintenance doses. 2.5 mg is for initiation only, and 7.5 mg and 12.5 mg exist as steps on the way up.
- SURMOUNT-1 measured results at 5 mg, 10 mg and 15 mg over 72 weeks: -15.0%, -19.5% and -20.9% in adults without diabetes.
- Zepbound and Mounjaro are the same molecule at the same six strengths with the same 15 mg ceiling. The licensed indication is what differs.
The tirzepatide dosage chart
The label splits the six strengths into three jobs. One is a starting dose that nobody stays on, three are maintenance doses, and two exist only so the step between maintenance doses is 2.5 mg rather than 5 mg.
| Dose | Role under the label | Earliest week it can start | Weight result reported in SURMOUNT-1 |
|---|---|---|---|
| 2.5 mg | Initiation only, not a maintenance dose | Week 1 | Not measured |
| 5 mg | Maintenance dose | Week 5 | -15.0% at 72 weeks |
| 7.5 mg | Step between 5 mg and 10 mg | Week 9 | Not measured |
| 10 mg | Maintenance dose | Week 13 | -19.5% at 72 weeks |
| 12.5 mg | Step between 10 mg and 15 mg | Week 17 | Not measured |
| 15 mg | Maximum dose | Week 21 | -20.9% at 72 weeks |
The week column is the earliest each strength can begin if every step is taken at the minimum four weeks. It is not a schedule anyone has to follow. The label allows a step to be held longer, and 5 mg and 10 mg are destinations in their own right rather than waypoints, which is why SURMOUNT-1 ran a 5 mg arm to 72 weeks and published a number for it.
How the four-week steps stack up
Read the ladder as a fastest-case calendar rather than a plan. SURMOUNT-1 built a 20-week dose-escalation period into its design for exactly this reason: participants assigned to 15 mg did not reach it until the fifth month.
| Weeks | Dose on the fastest ladder to 15 mg | What is happening |
|---|---|---|
| 1 to 4 | 2.5 mg | Initiation. No weight-loss endpoint was ever measured at this dose. |
| 5 to 8 | 5 mg | First maintenance dose. Some people stay here. |
| 9 to 12 | 7.5 mg | Intermediate step. |
| 13 to 16 | 10 mg | Second maintenance dose. |
| 17 to 20 | 12.5 mg | Intermediate step. |
| 21 onward | 15 mg | Maximum dose. |
The practical consequence is that the first four or five months of a real weight curve are not measuring the dose the headline came from. A 72-week trial average includes 20 weeks during which most participants were below their assigned dose, so early progress that looks slow against the headline percentage is often just the escalation period.
What each measured dose produced
Every figure here comes from the same trial, the same population and the same 72 weeks, which is what makes the doses comparable to each other. Mean body weight at baseline was 104.8 kg and mean BMI was 38.0.
| Dose | Mean weight change at 72 weeks | Lost 5% or more | Lost 20% or more |
|---|---|---|---|
| Tirzepatide 5 mg | -15.0% | 85% | Not reported |
| Tirzepatide 10 mg | -19.5% | 89% | 50% |
| Tirzepatide 15 mg | -20.9% | 91% | 57% |
| Placebo | -3.1% | 35% | 3% |
SURMOUNT-1, PMID 35658024, adults with obesity or overweight and no diabetes, 72 weeks, treatment-regimen estimand. From the trial's mean starting weight of 104.8 kg, -20.9% works out to roughly 21.9 kg, and -15.0% to roughly 15.7 kg. The step from 5 mg to 10 mg bought 4.5 percentage points; the step from 10 mg to 15 mg bought 1.4.
That shape matters when you read a dosage chart as a ladder to be climbed. Most of the difference between the bottom and the top maintenance dose had already appeared by 10 mg. We looked at the same trial from the other direction in our piece on how much weight you can lose on Zepbound.
The same doses in people with type 2 diabetes
SURMOUNT-2 ran 10 mg and 15 mg for 72 weeks in 938 adults with obesity and type 2 diabetes and recorded -12.8% and -14.7% against -3.2% on placebo (PMID 37385275). Same drug, same doses, same duration, roughly a third less weight lost. Any dosage chart that quotes one percentage per dose without saying which population it came from is mixing these two trials together.
See what each dose looks like in pounds
Run your own starting weight against the 5 mg, 10 mg and 15 mg trial percentages instead of reading them as abstractions.
Zepbound and Mounjaro: same doses, different label
Tirzepatide is sold under two brand names in the United States. Mounjaro is licensed for type 2 diabetes and Zepbound for chronic weight management. Both cover the same six strengths, both start at 2.5 mg, and both stop at 15 mg. There is no separate weight-loss dose and no higher diabetes dose.
What differs is the reason a dose gets changed. In type 2 diabetes the escalation is steered by glucose control, which is why SURPASS-2 used HbA1c as its primary endpoint when it compared tirzepatide 5 mg, 10 mg and 15 mg against semaglutide 1 mg over 40 weeks in 1879 patients, and reported weight change only as a secondary outcome (PMID 34170647). In weight management the escalation is steered by tolerability and by whether the response is enough.
Milligrams are not units
A large share of the searches behind this page ask for tirzepatide dosing "in units", which is a different question with a different answer. Units on a U-100 insulin syringe measure volume, not drug mass, so the same 10 mg can be a different number of units depending on the concentration in the vial in front of you. The arithmetic, and why a units figure copied from someone else's vial is meaningless, is in our mg to units conversion explainer.
What the chart says about stopping
SURMOUNT-4 is the trial that tested what the dose is holding up. All 783 participants took a maximum tolerated dose of 10 mg or 15 mg openly for 36 weeks and lost a mean 20.9%. The 670 who then continued reached 25.3% below their starting weight by week 88, while those switched to placebo regained 14.0% of their week-36 weight and finished the trial 9.9% below baseline (PMID 38078870).
Read alongside the dose-response table, that is the more useful way to think about a titration schedule. The difference between 10 mg and 15 mg was 1.4 percentage points over 72 weeks. The difference between staying on treatment and stopping it was 19.4.
FAQ
What is the maximum dose of tirzepatide?
15 mg once weekly, for both Zepbound and Mounjaro. There is no labelled strength above it, and SURMOUNT-1 measured -20.9% mean weight change at 15 mg over 72 weeks in adults with obesity and no diabetes.
How long does it take to get to 15 mg?
Twenty weeks at the fastest, because every strength above 2.5 mg requires at least four weeks on the dose below it. SURMOUNT-1 built a 20-week dose-escalation period into its design, so its 72-week averages include roughly five months at doses below the assigned one.
Is 5 mg of tirzepatide enough?
SURMOUNT-1 reported -15.0% at 72 weeks on 5 mg against -19.5% on 10 mg and -20.9% on 15 mg, all in adults with obesity and no diabetes. 5 mg is a labelled maintenance dose rather than a step, and it produced roughly three quarters of the weight change seen at the ceiling.
What are the 7.5 mg and 12.5 mg doses for?
They exist so the gap between maintenance doses can be crossed in 2.5 mg increments. SURMOUNT-1 did not have 7.5 mg or 12.5 mg arms, so no weight-loss percentage from that trial belongs next to either strength.
Do Zepbound and Mounjaro have different dosage charts?
No. Both are tirzepatide at the same six strengths with the same 2.5 mg start and the same 15 mg ceiling. The difference is the licensed indication, weight management for Zepbound and type 2 diabetes for Mounjaro, not the numbers on the chart.
Does a higher dose mean more side effects?
In SURMOUNT-1, adverse events caused treatment discontinuation in 4.3% of the 5 mg group, 7.1% of the 10 mg group, 6.2% of the 15 mg group and 2.6% of the placebo group, so the pattern was not a clean climb with dose. The detail is in our piece on tirzepatide side effects.
This article describes what the tirzepatide label and the SURMOUNT trials say. It is not medical advice and not a dosing instruction. Starting, changing, splitting or stopping a dose is a decision for your prescriber.
Sources
- Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). <em>N Engl J Med</em>. 2022;387(3):205-216. PMID: 35658024
- Garvey WT, Frias JP, Jastreboff AM, et al. Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes (SURMOUNT-2). <em>Lancet</em>. 2023;402(10402):613-626. PMID: 37385275
- Aronne LJ, Sattar N, Horn DB, et al. Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity (SURMOUNT-4). <em>JAMA</em>. 2024;331(1):38-48. PMID: 38078870
- Frias JP, Davies MJ, Rosenstock J, et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). <em>N Engl J Med</em>. 2021;385(6):503-515. PMID: 34170647
- Zepbound (tirzepatide) and Mounjaro (tirzepatide) United States prescribing information, Eli Lilly and Company, for the labelled strengths, the 2.5 mg starting dose, the four-week escalation interval and the 15 mg maximum.