GLP-1 Weight Loss Calculator & Tracker
See how much you could lose on Wegovy (injection or pill), Zepbound or Foundayo, or track whether you're ahead of the clinical-trial pace. Saved privately in your browser.
Key facts
- In the STEP 1 trial (1,961 adults, 68 weeks), semaglutide 2.4 mg (Wegovy) averaged −14.9% body weight, against −2.4% on placebo.
Medication
Dose
The highest-dose trial arm, so the most optimistic forecast; many people stay on a lower dose.
Goal & heightoptional, adds BMI
ExampleIf you match the trial average
−48lb
230 lb → 182 lb (−20.9%) in 72 weekson Zepbound 15 mg
Milestones
ring = share of SURMOUNT-1 participants who got there−5% · 219 lb
wk 8
91% got there
−10% · 207 lb
wk 16
84% got there
−15% · 196 lb
wk 29
71% got there
−20% · 184 lb
wk 56
57% got there
−25% · 173 lb
not by wk 72
36% got there
Share of SURMOUNT-1 participants on 15 mg who lost at least that much by week 72. A 5% loss already improves blood sugar, blood pressure and cholesterol.
General information from published research, not a diagnosis or medical advice. Talk to a doctor before changing medication or treatment. If a reading worries you, contact your care team. SourcesTerms
Dose schedule
Zepbound · mg per weekThe fastest schedule the label allows: start at 2.5 mg and step up 2.5 mg after at least 4 weeks on each dose. Your clinician may go slower: 2.5 mg is a starting dose, not a treatment dose.
Started already?Log your weigh-ins and see if you’re ahead of the trial pace.
Where the numbers come fromFive trials and the FDA labels
- Wegovy 2.4 mg (semaglutide): STEP 1 trial, Wilding JPH et al., N Engl J Med 2021;384:989–1002. 1,961 adults, 68 weeks: −14.9% vs −2.4% placebo (Wegovy label, Table 8).
- Wegovy 7.2 mg (Wegovy HD): STEP UP trial, Wharton S et al., Lancet Diabetes Endocrinol 2025;13:949–963. 1,407 adults with a BMI of 30 or more, 72 weeks: −18.8% vs −3.9% placebo (Wegovy label, Table 12).
- Wegovy pill 25 mg: OASIS 4 trial, Wharton S et al., N Engl J Med 2025;393:1077–1087. 307 adults, 64 weeks: −13.6% vs −2.4% placebo (Wegovy label, Table 11).
- Zepbound 5, 10 and 15 mg (tirzepatide): SURMOUNT-1 trial, Jastreboff AM et al., N Engl J Med 2022;387:205–216. 2,539 adults, 72 weeks: −15.0%, −19.5%, −20.9% vs −3.1% placebo (Zepbound label, Table 2).
- Foundayo 5.5, 9 and 17.2 mg (orforglipron): ATTAIN-1 trial, Wharton S et al., N Engl J Med 2025;393:1796–1806. 3,127 adults, 72 weeks: −7.4%, −8.3%, −11.1% vs −2.1% placebo (Foundayo label, Table 6).
- Week-by-week shape: the average at each clinic visit, read from the Wegovy label (Figures 7 and 10), the Zepbound label (Figure 3), the Foundayo label (Figure 1) and the FDA’s clinical review of Wegovy tablets (NDA 218316, Figure 12).
- Milestone shares and dose schedules: the FDA prescribing information on DailyMed (Wegovy injection and tablets, June 2026; Zepbound, August 2026; Foundayo, July 2026).
- Type 2 diabetes trials: STEP 2 (Wegovy label, Table 8), SURMOUNT-2 (Zepbound label, Table 2) and ATTAIN-2 (Foundayo label, Table 6).
- Mounjaro for weight management outside the US: Mounjaro product information, section 4.1 (European Medicines Agency; UK summary of product characteristics, August 2026).
- Weight regain after stopping: Wilding JPH et al., Diabetes Obes Metab 2022 (STEP 1 extension).
- Approved since STEP 1 and SURMOUNT-1 (FDA approval letters, Drugs@FDA):
- Wegovy pill (semaglutide 25 mg tablets), Dec 22, 2025 (FDA approval letter, NDA 218316). In the forecast as “Wegovy pill”, from OASIS 4.
- Zepbound multiple-dose vial, Jan 7, 2026 (FDA approval letter, NDA 217806/S-037). Same medicine and doses as the Zepbound pen, so the Zepbound forecast applies.
- Zepbound KwikPen (4 doses per pen), Jan 20, 2026 (FDA approval letter, NDA 217806/S-002). Same medicine and doses as the Zepbound pen, so the Zepbound forecast applies.
- Wegovy HD (semaglutide 7.2 mg injection), Mar 19, 2026 (FDA approval letter, NDA 215256/S-029). In the forecast as Wegovy 7.2 mg, from STEP UP.
- Foundayo (orforglipron tablets), Apr 1, 2026 (FDA approval letter, NDA 220934). In the forecast at 5.5, 9 and 17.2 mg, from ATTAIN-1. Not at 14.5 mg: no trial arm stayed on that dose.
Next
How this works: Method, 8 sources, Checked against 8 worked examples,
How this works
Method
It applies the average weight change from each medication’s main trial, as printed in its FDA label, to your starting weight: STEP 1 for Wegovy 2.4 mg, STEP UP for Wegovy 7.2 mg, OASIS 4 for the Wegovy pill, SURMOUNT-1 for Zepbound and ATTAIN-1 for Foundayo. The week-by-week line follows each trial’s published average at every clinic visit, scaled to its end result and held flat after it. The share of participants reaching your goal is read between the trial’s published milestone rates.
Sources
- Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1) (N Engl J Med, 2021)
- Once-weekly semaglutide 7.2 mg in adults with obesity (STEP UP) (Lancet Diabetes Endocrinol, 2025)
- Oral Semaglutide at a Dose of 25 mg in Adults with Overweight or Obesity (OASIS 4) (N Engl J Med, 2025)
- Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1) (N Engl J Med, 2022)
- Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment (ATTAIN-1) (N Engl J Med, 2025)
- Wegovy, Zepbound and Foundayo prescribing information (results tables and visit-by-visit figures) (U.S. Food and Drug Administration, 2026)
- Clinical review of Wegovy tablets, NDA 218316 (OASIS 4 visit-by-visit figure) (U.S. Food and Drug Administration, 2026)
- STEP 1 trial extension (weight regain after stopping semaglutide) (Diabetes Obes Metab, 2022)
How it’s tested
8 worked examples for this page are checked by automated tests before every release: given the inputs, the tool must show the expected answer.
Limits
General information from published research, not a diagnosis or medical advice. Talk to a doctor before changing medication or treatment. If a reading worries you, contact your care team.
Privacy
On your device. Nothing you enter or open leaves this browser. About privacy labels
Changes
- Added Wegovy 7.2 mg (STEP UP), the Wegovy pill (OASIS 4) and Foundayo (ATTAIN-1), from their FDA labels.
- The week-by-week line now follows each trial’s published visit averages, so early weeks are no longer overstated; fixed the FAQ on who the trials enrolled.
- “Print for my doctor” now prints a report with your inputs, the week-by-week chart, milestones, your weigh-ins and the trial sources.
- Added key facts from the STEP 1 and SURMOUNT-1 trials; the disclaimer became one quiet line under the result.
- Usage statistics no longer record which medication or dose you picked.
- Redesigned: a new forecast chart with milestone dots, your goal and your weigh-ins, a milestone track, a dose schedule and a printable page for your doctor.
- First published: a week-by-week Wegovy and Zepbound forecast from the clinical trials, with a private weigh-in tracker.
Frequently Asked Questions
How is this forecast calculated?
It applies the average result from the medication’s main clinical trial, as given in its FDA prescribing information, to your starting weight: STEP 1 for Wegovy 2.4 mg (−14.9% at 68 weeks), STEP UP for Wegovy 7.2 mg (−18.8% at 72 weeks), OASIS 4 for the 25 mg Wegovy pill (−13.6% at 64 weeks), SURMOUNT-1 for Zepbound 5, 10 and 15 mg (−15.0%, −19.5% and −20.9% at 72 weeks) and ATTAIN-1 for Foundayo 5.5, 9 and 17.2 mg (−7.4%, −8.3% and −11.1% at 72 weeks). The week-by-week shape follows each trial’s published chart of the average weight at every clinic visit, scaled to that end result, so the first weeks match what participants lost while their dose was being raised.
Can I track my own progress here?
Yes. Choose “Already taking it”, enter your first-dose date and starting weight, and log a weigh-in whenever you like (weekly works best). The page plots you against the clinical-trial average, tells you whether you are ahead of or behind that pace, and makes a weekly check-in card you can post. Your entries are saved only in this browser on this device. Nothing is uploaded, so come back on the same browser to continue. You can export them as a CSV or clear them at any time.
Why are your numbers lower than some I have seen online?
Trials report two kinds of averages. We use the “treatment-policy” result, which counts everyone who started, including people who stopped the drug. The “if taken as intended” result is higher: −16.9% for semaglutide 2.4 mg and −22.5% for tirzepatide 15 mg. Many articles quote the higher figure without saying which one it is. We stick to one kind throughout so the comparisons are fair.
Is Ozempic the same as Wegovy?
Both are semaglutide. Ozempic is approved for type 2 diabetes, at doses up to 2 mg a week. Wegovy is the version approved for weight management: a weekly injection (2.4 mg, or 7.2 mg as Wegovy HD) or a daily 25 mg pill. Tirzepatide is sold as Mounjaro and Zepbound. In the US, Mounjaro is approved only for type 2 diabetes and Zepbound for weight management; in the UK and the EU, Mounjaro is licensed for weight management too. It is the same medicine, so the Zepbound forecast (SURMOUNT-1) applies to Mounjaro at the same dose.
How likely am I to reach my goal?
Individual results vary a lot around the average. The trials report what share of participants lost at least 5%, 10%, 15% and 20% (and, for Zepbound, 25%) of their body weight. When you enter a goal, we show the share of trial participants who got there. Beyond the highest published threshold we can only say “fewer than” that share.
What happens if I stop taking it?
Weight tends to come back. In the STEP 1 extension (Wilding et al., Diabetes, Obesity and Metabolism 2022), participants regained about two-thirds of the weight they had lost within a year of stopping semaglutide, and cardiometabolic improvements largely reversed. These medications are intended as long-term treatment.
Who can be prescribed these medications?
The FDA labels cover adults with obesity (a BMI of 30 or more), or with overweight (27 or more) and at least one weight-related condition such as high blood pressure or high cholesterol. The trials used here enrolled people in that range (STEP UP, for Wegovy 7.2 mg, only a BMI of 30 or more) and excluded people with type 2 diabetes. Separate trials in people with type 2 diabetes found smaller average losses: −9.6% on Wegovy 2.4 mg at 68 weeks (STEP 2), −12.8% and −14.7% on Zepbound 10 and 15 mg at 72 weeks (SURMOUNT-2) and −9.6% on Foundayo 17.2 mg at 72 weeks (ATTAIN-2). So if you have type 2 diabetes, this forecast is likely too optimistic. Only a clinician can decide whether a medication is right for you.
Does the dose schedule affect early weight loss?
Every option starts low and steps up to reduce nausea: Wegovy reaches 2.4 mg at week 17 (and 7.2 mg at week 21 at the earliest), the Wegovy pill reaches 25 mg on day 91, Zepbound reaches 15 mg at week 21 at the earliest, and Foundayo steps up at least 30 days apart. In the trials, weight came off steadily while the dose was going up: STEP 1 participants lost about 0.5% of their weight a week up to week 20, and the averages levelled off only after about a year. The forecast follows each trial’s own visit-by-visit average, so its first weeks match what participants lost during the step-up. Many people stay on a lower dose if a higher one is not tolerated.
Wegovy and Ozempic are trademarks of Novo Nordisk A/S; Zepbound, Mounjaro and Foundayo are trademarks of Eli Lilly and Company. Binary Decimal is not affiliated with or endorsed by them.