How Much Weight People Lost on Zepbound, Wegovy and Foundayo
Average weight loss from the main trials for tirzepatide, semaglutide and orforglipron — and the one number that matters more than the averages.
Three medications dominate the conversation right now. Here's what each one actually did in its main trial.
| Medication | Brand | How it's taken | Average weight loss |
|---|---|---|---|
| Tirzepatide | Zepbound, Mounjaro | Weekly injection | 20.9% at 72 weeks (SURMOUNT-1) |
| Semaglutide | Wegovy, Ozempic | Weekly injection or daily tablet | 14.9% at 68 weeks (STEP 1) |
| Orforglipron | Foundayo | Daily tablet | 12.4% at 72 weeks (ATTAIN-1) |
For scale, placebo groups in those trials lost around 2%.
Tirzepatide's number climbs with dose — 16.0% at 5mg, 21.4% at 10mg, 22.5% at 15mg. And the one head-to-head trial that exists, SURMOUNT-5, had tirzepatide out in front of semaglutide.
The number that matters more
Those are averages, and the spread around them is enormous. In STEP 1, the standard deviation was 9.3 percentage points. In plain terms: plenty of people on semaglutide lost 25%, and plenty lost 5%, and both of those are inside the normal range that produced a 14.9% average.
So the average tells you what the drug does across thousands of people. It tells you very little about what it will do for you.
Key point
Two other things these numbers quietly assume. Every one of these trials paired the medication with diet and activity counselling — the drug wasn't working alone. And they're separate trials with different participants, so comparing across rows is rough, not a ranking.
What to do with this
Use them as a sanity check, not a target. If you're six months in and well off the average, that's information worth bringing to your prescriber — dose, adherence and side effects all move this. But being below an average that half the trial was also below is not, by itself, a sign anything is wrong.
Important
General education, not medical advice, and not a recommendation of any medication. Which one is right for you — if any — is a conversation with your own clinician.
More on what shapes your own curve: what the research says about muscle loss and why the weekly schedule exists at all.
This article is general education, not medical advice. Talk to your healthcare provider about your own treatment.