Free Tool
GLP-1 Weight Loss Calculator
Choose a medication to see the average weight change published for it in its own clinical trial. Each medication is shown with its own trial; the results are never averaged or combined, because the trials enrolled different people for different lengths of time.
In SURMOUNT-1, adults taking Zepbound 10 mg had lost an average of 19.5% of their body weight by week 72. For a starting weight of 233 lb that is about 45 lb. Individual results in the trial varied widely: 88.9% of participants lost at least 5%, and 50.1% lost at least 20%. The placebo group lost an average of 3.1%. Everyone in the trial also received diet and physical activity counselling.
233 lb is the average starting weight of that group in the trial. Enter your own to apply the same average to it. This is the average result of a clinical trial, not a prediction of yours.
The published result for each medication
Zepbound weight loss calculator
In SURMOUNT-1, adults taking Zepbound 10 mg had lost an average of 19.5% of their body weight by week 72. For a starting weight of 233 lb that is about 45 lb. Individual results in the trial varied widely: 88.9% of participants lost at least 5%, and 50.1% lost at least 20%. The placebo group lost an average of 3.1%. Everyone in the trial also received diet and physical activity counselling.
Ozempic weight loss calculator
In SUSTAIN 1, adults with type 2 diabetes taking Ozempic 1 mg had lost an average of 4.7 kg (10.4 lb) by week 30, from an average starting weight of 96.9 kg. This trial was in people with type 2 diabetes, where weight loss is typically smaller than in obesity trials of the same medication; see the Wegovy page for those.
Wegovy weight loss calculator
In STEP 1, adults taking Wegovy 2.4 mg had lost an average of 14.9% of their body weight by week 68. For a starting weight of 232 lb that is about 35 lb. Individual results in the trial varied widely: 83.5% of participants lost at least 5%, and 30.2% lost at least 20%. The placebo group lost an average of 2.4%. Everyone in the trial also received diet and physical activity counselling.
Mounjaro weight loss calculator
In SURPASS-2, adults with type 2 diabetes taking Mounjaro 10 mg had lost an average of 9.3 kg (20.5 lb) by week 40, from an average starting weight of 94.8 kg. This trial was in people with type 2 diabetes, where weight loss is typically smaller than in obesity trials of the same medication; see the Zepbound page for those.
GLP-1 weight loss calculator questions
What is a GLP-1 weight loss calculator?
On this site it is a lookup of published clinical trial results: you choose a medication and a dose, and it shows the average weight change reported for that group in the medication's own trial. For the obesity trials it also applies that average to the starting weight you enter. It is not a prediction of your own result.
Which GLP-1 medication had the largest weight loss in its trial?
In SURMOUNT-1, the average weight loss at week 72 was 15.0% on 5 mg, 19.5% on 10 mg and 20.9% on 15 mg, against 3.1% on placebo. In STEP 1, the average weight loss at week 68 was 14.9% on 2.4 mg, against 2.4% on placebo. These two trials enrolled different people for different lengths of time, so the figures are not a head-to-head comparison.
Why are Ozempic and Mounjaro shown separately from Wegovy and Zepbound?
Ozempic and Mounjaro are approved for type 2 diabetes, and their prescribing information reports body weight from trials in adults with type 2 diabetes, in kilograms. Wegovy and Zepbound contain the same medications (semaglutide and tirzepatide) and report weight from trials in adults with obesity or overweight, in percent. Each page shows only its own trial.
Does the calculator average the results of different medications?
No. The trials enrolled different people, ran for different lengths of time and measured weight in different ways, so averaging or combining them would produce a number no trial observed.
Is this a prediction of my weight loss?
No. It reports what happened on average in a trial. It cannot account for your health, your dose changes, your diet or your activity, and individual results in every trial varied widely. Talk to your prescriber about what to expect.
Where do these numbers come from?
Section 14 of each medication's FDA prescribing information, as published on DailyMed. Each medication's page names the trial, the table or paragraph the figures were copied from, and the date of the label.
Can this calculator tell me which medication or dose to take?
No. It does not recommend a medication or a dose. Those decisions are made with your prescriber.
By GLP AI / Editorial. The trial figures and result wording on this page were reviewed by Teresa Maze, RDN, on September 18, 2026. The review did not cover anything else on the page.
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. The information provided should not be used for diagnosing or treating a health condition. Always consult your healthcare provider before starting, stopping, or changing any medication or treatment plan. Individual results may vary.