How Much Weight Will I Lose on Zepbound or Wegovy?

Almost everyone brings a number to the first appointment. Sometimes it's scribbled in the margin of the intake form, and sometimes it comes out before I've finished washing my hands. Fifty pounds. Or whatever they weighed at their wedding. The number is usually round, and it's usually attached to a date that is a lot closer than it should be.

I don't argue with it. I write it down, because it matters to the person who said it and because it tells me what they're hoping this medication will do for them. Then I ask for a second number, which almost nobody has prepared: what do you expect to weigh at the end of your third month?

That one gets a pause. People have been thinking about the finish line for years. They have rarely thought about the shape of the road, and the shape is where most of the disappointment on these drugs happens, somewhere in the middle, in those weeks when the scale sits still and a coworker on the same shot seems to be shrinking by the day.

So this isn't really a piece about one number. The trial averages are real and I'll give them to you, in pounds, but they describe where a large group of people ended up after a year and a half. What follows is closer to what I say across the desk. Roughly what each stretch of the first two years looks like, why the early months feel slow, where the curve bends, and what it does if you get off.

The first three months, while the dose is still climbing

Neither drug starts at the dose that produced the headline results. That single fact explains most of the frustration I hear in the first twelve weeks.

Wegovy begins at 0.25 mg once a week. After four weeks it goes to 0.5 mg, then 1 mg, then 1.7 mg, and only after that to 2.4 mg, which is the dose studied in the big trials. Four weeks at each step means the earliest anyone reaches the full dose is around week 17, so about four months in, and that's if nothing gets delayed along the way. Zepbound follows the same logic with different numbers. You start at 2.5 mg and go up by 2.5 mg no sooner than every four weeks, which puts the 15 mg dose around week 21 at the earliest. Plenty of people never go that high and do fine at 5 or 10 mg.

Those low starting doses are there so your stomach and your brain can get used to the drug without making you miserable, and any weight that comes off during them is a bonus. Nausea and that full-after-four-bites feeling are most common right after a dose goes up, and going slowly is how we keep them tolerable. I would much rather someone spend an extra month at a lower dose than quit in week six because they were throwing up in the car.

What does the scale do during this time? Something, usually. Appetite quiets down early for a lot of people, sometimes after the first or second injection, and eating less does show up. But it tends to be modest and uneven, and it almost never matches the pace that the goal number from the first visit quietly assumed. One week drops two pounds. The next week, nothing. A salty dinner out or a few days of constipation (common on these drugs) can hide a real loss for a week or longer.

Clothes lag behind the scale, too. People are often down a fair amount before anyone at work says a word, which is its own small letdown.

The emotional part of this stretch gets underrated. You've paid for the medication or fought your insurance company for it. You're giving yourself a shot every week and dealing with a stomach that doesn't feel quite like yours. And the reward, so far, is smaller than what you pictured when you said that number out loud in my office. It's very easy to decide it isn't working. What I tell people in month two is that they're grading a drug at a fraction of the dose it was tested at. You wouldn't judge a blood pressure pill by the first quarter tablet.

The thing I actually watch in these months is direction, not size. If appetite has changed and the trend over a month is down, even slowly, that's the right start. If weight is completely flat or climbing by the end of month three, that deserves a real conversation. Sometimes the dose is the issue or injections are being missed. Sometimes something else is pushing the other way, like another medication known to cause weight gain or a thyroid problem that was never checked.

There's a separate breakdown of how long Ozempic takes to work that goes deeper into the first few weeks, and since Ozempic is the same molecule as Wegovy, most of it applies here.

Months three to six

This is usually when it starts to feel like the drug you read about.

By now most people on Wegovy are at or close to 1.7 or 2.4 mg, and people on Zepbound are partway up the ladder or already settled on a dose that works for them. The appetite change becomes steadier. Food noise, which is what a lot of my patients call it, is low most days rather than some days.

We have a surprisingly clean look at this window from STEP 4, a Wegovy trial published in JAMA in 2021. Everyone in it started on semaglutide and worked up to 2.4 mg, and after 20 weeks, a little under five months, the average loss was about 10.6% of body weight. For someone who started at 230 pounds that's a little over 24 pounds, a bit more than a pound a week. Those twenty weeks include the slow escalation months, though, so the pace in months four and five is usually quicker than the average makes it sound.

A pound a week. Say that to someone who walked in hoping to lose fifty pounds by summer and watch their face fall a little. It isn't dramatic. Over a year, though, it adds up to something most diets never come near, and that's the reframe I push hard in this stretch. Stop measuring weeks. Measure months.

Practically, I suggest weighing a few times a week, same time of day, and then comparing where the number sits at the end of each month with where it sat the month before. Daily weights on these drugs are noisy enough to make a calm person anxious.

The old Saxenda label (liraglutide, an earlier drug in this family) told prescribers to reassess and stop if a person hadn't lost at least 4% after 16 weeks. That rule isn't written into the Wegovy or Zepbound labels, and I don't use it as a hard cutoff. But post hoc analyses suggest that how someone does in the first few months on a treatment dose tends to predict where they end up, at least loosely. So a person comfortably past 5% by month five is very likely headed somewhere good. Someone barely moving at that point is less likely to catch up to the average, and I'd rather talk honestly about that now than wait another six months on hope.

If you're still deciding between the two, this is the stretch where the gap tends to show. Tirzepatide has simply been more effective on average. In SURMOUNT-5, the head-to-head trial published in NEJM in 2025, people on tirzepatide lost 20.2% at 72 weeks compared with 13.7% on semaglutide. When insurance and side effects allow it, and the main goal is the largest possible loss, I lean toward Zepbound. Wegovy is still a very good drug and I prescribe plenty of it. I just can't look at that trial and pretend the two came out even.

Some people move more slowly on either one, and it helps to know that going in. People with type 2 diabetes lose less on average: 9.6% at 68 weeks on Wegovy in STEP 2, and 12.8% to 14.7% on Zepbound in SURMOUNT-2, depending on the dose. Men lost a smaller percentage than women on average in subgroup analyses of both STEP 1 and SURMOUNT-1. If that's you, your curve may simply be gentler than the one in the brochure, and comparing yourself to your sister or your neighbor is a good way to feel bad for no medical reason.

Six months to a year, and why the curve bends

Somewhere in the back half of the first year the line starts to flatten. Almost everyone notices. Almost everyone assumes they did something wrong.

They usually didn't. The flattening is built into how these medications work, and the trials show it clearly. In STEP 1, the main Wegovy trial published in NEJM in 2021, weight loss continued until roughly week 60 and then leveled off. Week 60 is about fourteen months. The average at the end, 68 weeks, was 14.9% compared with 2.4% on placebo, in a group that started around 231 pounds.

STEP 4 shows the slowdown inside a single group of people. After those first 20 weeks and roughly 10.6% lost, the ones who stayed on semaglutide lost another 7.9% over the rest of the trial, which ran out to week 68. So twenty weeks produced more loss than the forty-eight weeks after them. The line drops fast and then eases off.

Tirzepatide draws the same shape from a higher starting point. In SURMOUNT-4, participants spent 36 weeks on tirzepatide and lost about 20.9% on average in that time, and those who kept taking it lost an additional 5.5% afterward. Most of the loss lands in the first eight or nine months. What comes after is real but smaller.

Why does this happen? Your body adjusts. A lighter body burns less energy, and the hunger signals these drugs turn down start pushing back somewhat. Eventually what you eat and what you burn meet again at a new, lower weight, and the medication holds you there. That's the plateau, and on these drugs the plateau is more or less the goal, even though almost everyone reacts to it like the car broke down.

Now the pounds, since that's what everyone really wants. On Wegovy, 14.9% of a 230 pound starting weight works out to about 34 pounds.

Zepbound depends a lot on the dose you land on. In SURMOUNT-1, the main Zepbound trial, people started around 231 pounds, same as STEP 1, and lost 15.0% on average at 5 mg. On 10 mg it was 19.5%. The 15 mg group got to 20.9%, while placebo managed 3.1%. So for our 230 pound person on the top dose, call it 48 pounds.

If you're lighter or heavier than that, just do the multiplication. A woman starting at 180 who loses 15% is down 27 pounds, and if she gets to 20% it's 36. Somebody starting at 300 is looking at 45 pounds at 15%, and 63 if they reach 21%.

Those are averages, and people scatter widely around them. Most people in STEP 1 cleared 10%, about 69% of them. Only about half reached 15%, though, and roughly a third went past 20%. Zepbound at 15 mg did better on that last measure, with a little over half of people losing a fifth of their body weight. A good chunk of people end up well past the average, and a real minority end up well short of it. The goal number from that first appointment may be completely reachable. It may also be sitting up in the top third of the distribution, and I think people deserve to hear that plainly in month eight rather than figure it out alone in month fourteen.

The months between six and twelve test patience in a different way than the early ones did. The weight is off. Now the scale moves a pound or two a month, if that, and it's easy to feel like progress stopped. In reality you're doing the most valuable thing these drugs do, which is keeping the loss. I sometimes point out that a year at a steady lower weight is something many of my patients have never had in their adult lives. Every diet before this one went down and then came back up right about now.

One more thing I bring up in this window. Body composition substudies suggest a meaningful share of the weight lost on GLP-1 medications can be lean tissue, not only fat. That's why I get more insistent about protein and some form of strength work once the fast loss slows down. You want the new weight to be well built, not just smaller.

Year two and beyond

Year two is quiet. It's supposed to be.

STEP 5 followed people on Wegovy for 104 weeks, two full years, and the average loss at the end was 15.2%. Put that next to the 14.9% at 68 weeks in STEP 1. They're different trials, so I wouldn't make much of the small gap, but the message is plain enough: the weight didn't keep falling through the second year, and it didn't creep back either.

After the first year, success mostly looks like a stable number and a refill.

Now the blunt part. Trial averages come from people who kept taking the drug at the studied doses for the length of the trial. Real life is messier. Large health system data published in 2024 and 2025 have generally come in below the trial results, mostly because many people stop early. Others stay at lower doses, and supply shortages or coverage changes interrupt treatment for plenty more. Pharmacy claims analyses from Prime Therapeutics found that only about one in three people prescribed a GLP-1 for weight loss were still taking it at one year, and a later analysis found about 1 in 12 still on it at three years.

That second figure stays with me. It means most people who start one of these drugs never reach year two, so most people never find out what the trial curve would have done for them. When someone asks how much they'll lose, a big part of my honest answer is that it depends on whether they're still taking it eighteen months from now.

Cost drives a lot of that. Zepbound self-pay vials through LillyDirect run $299 to $449 a month, and Medicare Part D started covering these medications for weight loss for eligible patients at $50 a month in July 2026. Coverage still shifts from year to year, and every shift is a chance for a gap. If you're weighing price and format across the options, the broader guide to weight loss medications is a reasonable place to compare.

Some people ask about moving to a pill once the weight is off. The Wegovy pill reached about 13.6% at 64 weeks in OASIS 4 (with fasting rules), and Foundayo, approved April 1, 2026, about 12.4% at its highest dose in ATTAIN-1. What we don't have is good data on switching from a shot to a pill just to hold a loss. I'm open to it. I don't pretend we know how it goes.

There's also a longer piece on how long weight loss medication takes that covers the timeline across the other drugs in this class, if you're comparing more than these two.

What happens if you stop

This is the part people least want to hear, so I bring it up at the first visit.

The most common plan I hear from new patients is to lose the weight on the shot and then come off and hold it with willpower. I get why. I just wish the data backed it up.

When people in the STEP 1 extension stopped semaglutide, about two thirds of the weight they'd lost was back within a year.

STEP 4 looked at it more directly. After those first 20 weeks, some people were quietly switched to placebo, and they regained 6.9% of their body weight. The ones who stayed on semaglutide went the other way and lost another 7.9%. SURMOUNT-4 ran the same experiment with tirzepatide, after 36 weeks and about 20.9% already lost, and got an even starker split: roughly 14% regained on placebo, another 5.5% lost for the people who kept going. Same people, same starting point. The only thing that changed was whether the medication was still in the syringe.

Regaining after you stop says nothing about your character. The appetite the drug was quieting comes back, usually along with the body's own drive to return to its old weight, and the people in those placebo groups weren't failing at anything. I say this plainly because the shame of regaining is often worse than the pounds themselves, and it keeps people from coming back in when coming back would help.

So my stance is simple. If these medications work for you, plan on treating them the way you'd treat blood pressure or cholesterol medication, as something ongoing. Some people want to try a lower dose once they're stable. I'll do that carefully, though the data on it is thin. Sometimes stopping entirely is necessary, because of cost or because of side effects that never settled. When that happens, it helps to go in expecting some regain and to have a plan for it, rather than being blindsided three months later.

And for the ones who stay on it, the visits get short. The weight is within a couple of pounds of last time. We talk about their knee for a minute, or a cruise they have coming up. I send the refill. On the way out they ask whether the front desk still validates parking.

It does.