Average weight loss on Mounjaro, based on your BMI.
Answer a few questions and find out how much weight you could lose and how quickly.
Which GLP-1 medication are you on, or thinking about?
Mounjaro and Zepbound are the same molecule on different labels, and Mounjaro vs Zepbound shows where their approved uses differ. To compare it with semaglutide, see Mounjaro vs Ozempic.
The same tool for other medications: GLP-1 weight loss calculator, Ozempic weight loss calculator, Wegovy weight loss calculator, Semaglutide weight loss calculator, Zepbound weight loss calculator, and Tirzepatide weight loss calculator.
Sources: STEP-1 ↗ · SURMOUNT-1 ↗
Related: Mounjaro · Mounjaro vs Zepbound · Zepbound
How the Mounjaro weight loss calculator works
Enter your weight and height, then pick a medication and dose. The tool takes the average weight loss measured in that drug's main clinical trial: STEP-1 for semaglutide, SURMOUNT-1 for tirzepatide. It maps that trial figure onto your starting weight, plotting your projected weight and BMI week by week. The numbers come straight from the published trials, not a generic calorie formula.
This calculator uses SURMOUNT-1, which tested tirzepatide for weight in adults without diabetes. Mounjaro is the same molecule. Its label covers type 2 diabetes. A Mounjaro result can differ from this estimate.
What SURMOUNT-1 found
SURMOUNT-1 gave 2,539 adults with obesity, or overweight with a weight-related condition, and no diabetes, weekly tirzepatide or placebo for 72 weeks. Mean weight change was −15.0% on 5 mg, −19.5% on 10 mg, and −20.9% on 15 mg, against −3.1% on placebo. The first 20 weeks were dose escalation.
| Group | Mean weight change, week 72 | Lost 5% or more |
|---|---|---|
| Tirzepatide 5 mg | −15.0% | 85% |
| Tirzepatide 10 mg | −19.5% | 89% |
| Tirzepatide 15 mg | −20.9% | 91% |
| Placebo | −3.1% | 35% |
How much weight will I lose in 4 months on Mounjaro?
No published figure answers this for month 4. SURMOUNT-1 reported weight at week 72. Its first 20 weeks were a dose-escalation period. The calculator's curve before week 72 is our model of how the trial average builds, not a measured value. Enter your weight above and read week 16 off the chart.
What is the average first month weight loss on Mounjaro?
Neither SURMOUNT-1's published results nor the Mounjaro label give a first-month average. SURMOUNT-1 tested tirzepatide for weight management, the use the Zepbound label covers. The Mounjaro label gives 2.5 mg once weekly as the recommended starting dosage and describes raising it in 2.5 mg increments after at least 4 weeks on the current dose when more glycemic control is needed.
Can you lose 20 pounds in 2 months on Mounjaro?
Twenty pounds in two months is about 2.3 pounds a week. The CDC says people who lose weight at a gradual, steady pace of about 1 to 2 pounds a week are more likely to keep it off. SURMOUNT-1 reports an average at week 72, not at two months. Enter your weight above to see where the modeled curve sits at week 8.
What is a healthy amount of weight to lose per week on Mounjaro?
The CDC describes about 1 to 2 pounds a week as a gradual, steady pace, and says people who lose at that pace are more likely to keep the weight off. SURMOUNT-1 reports an average at week 72, not a weekly target. Your prescriber is the one to judge your own pace.