Two Years on a GLP-1: Does Staying on It Keep the Weight Off?

A year in, I figured the suspense was over. It wasn't.

By month twelve I'd landed near the number I'd been aiming at, and a quieter question moved in to replace the loud one. Not is this working anymore — that part I could see. The new one was slower and a little colder: if I just keep going, does year two hold? I don't mean what happens if I stop. That's a different question with its own data, and I'll be strict about not smuggling it in here. I mean the plain version. Stay on the shot. Keep the routine. Does the weight stay down once the calendar rolls past one year?

So I went looking for the trial that asks exactly that, and read it the way I'd want a friend to read it back to me — without the hype, and without pretending the average is a promise.

One ground rule first, same as the first-year piece: every figure below comes from a published trial, not my bathroom scale. I'm not going to hand you my own before-numbers as if they were evidence, because my body isn't a study and neither is yours. What I can do is lay the two-year data over the worry that sent me searching and show you where they line up — and where they don't.

The drug here is semaglutide at the 2.4 mg weekly dose, the one sold as Wegovy for weight management. Same molecule as Ozempic, higher dose, pointed at obesity rather than type 2 diabetes.

What STEP 5 set out to watch

The trial is called STEP 5, and it did the thing a lot of weight-loss studies skip: it kept watching into a second year. Its results were published in Nature Medicine in 2022. Adults took either semaglutide 2.4 mg once a week or a placebo shot, and — this part matters — both groups also got the same lifestyle support, the diet-and-activity scaffolding underneath the injection. So nothing you're about to read is the drug working in a vacuum. It's the drug plus the routine, measured against the routine alone.

The clock ran to 104 weeks. That's two years, near enough, but I'm going to keep saying 104 weeks, because "two years" is a rounding I'd rather not lean on when the trial itself measured to the week. On the registry, the headline endpoint was written plainly: the percentage change in body weight from the start (week 0) out to week 104. The paper's co-primary endpoints were that percentage change and the share of people who hit at least 5% loss — both read at the 104-week mark, not somewhere convenient in the middle.

Here's the design detail that turns this into a staying-on-it study rather than a snapshot: people spent about 16 weeks climbing the dose ladder up to 2.4 mg, then held at that maintenance dose for another 88 weeks. Sixteen plus 88 is your 104. Nobody stepped off at a year to see what happened. The whole point was to keep the treatment running and watch.

Year two, and what those two numbers mean

At 104 weeks, the semaglutide group sat 15.2% below where they'd started. The placebo group — again, same lifestyle program — ended 2.6% below their own starting weight.

Read those as two separate stories, not one. The 15.2% is the semaglutide group's total change from its own baseline. The 2.6% is the placebo group's total change from its baseline. Neither number sits on top of the other. The distance between the two lines is 12.6 percentage points, and that gap is the trial's estimated treatment difference — the slice you can reasonably hang on the drug, once you've set aside the loss that showed up with lifestyle support alone.

That "percentage points" tag is doing quiet work, so let me be a pain about it. 12.6 is a distance between two figures, not a third weight-loss number, and it doesn't stack onto the 15.2. If you ever find yourself adding these three together, stop — you've mixed up a group's total loss with the gap between two groups.

The quieter note buried in that table: placebo wasn't a straight bounce back to zero. On lifestyle support alone, that group was still a little below where they'd begun at two years. The story of STEP 5 isn't "drug or total relapse." It's the size of the gap between staying on treatment and not.

How many people kept the weight off

An average can hide a lot, so the more useful question is: how many people were still holding real loss at the two-year mark? STEP 5 counted that too, and this is a different kind of number — a share of participants, not an amount of weight. It answers "how many people," not "how much."

At 104 weeks, 61.8% of the semaglutide group were still down at least 10% of their body weight, against 13.3% on placebo. Push the bar higher: 52.1% were still down at least 15%, versus 7.0% on placebo. The full ladder ran from 77.1% holding at least 5% at the top down to 36.1% holding at least 20% at the bottom.

Now the trap, because it catches everyone. These rungs sit inside each other, not beside each other. Everybody counted in the 15% row is also counted in the 10% row, and again in the 5% row. So you cannot add them up. Do the math anyway and you'd sail past 100% of a group that, being a group of humans, tops out at exactly 100%.

The clean way to read it: a bit over half the semaglutide group — 52.1% — was still down 15% or more after two years, and most of the people who'd held onto 10% had held onto 15% too. That's a real staircase of outcomes, and the fact that it is a staircase, not a single step everyone stands on, is the whole point of the next part.

Why the average still isn't your number

Here's where I have to talk myself down, and maybe you too. It's tempting to see −15.2% and quietly file it as my year-two result, already reserved. It isn't. It's the middle of a crowd.

That responder ladder up above is the proof. If everyone landed at the average, there'd be no ladder — just one number, over and over. Instead you get 36.1% down 20% or more, and 77.1% down at least 5%, and every gradation between. Some people in that trial did far better than the average. Some did more modestly. The mean is the balance point of all of them, not a slot with your name on it.

The average is where the group settles, not where you're guaranteed to land. Read −15.2% as "this is roughly what continued treatment did across about 150 people," and read the ladder as the plain reminder that individual results fan out on both sides of it.

None of this makes the two-year picture less encouraging. A majority still holding double-digit loss at 104 weeks is a genuinely durable result, and the gap over placebo is wide. It just means the right takeaway is a range with your name not pre-written into any one spot on it — which is exactly the kind of thing worth talking through with the person who actually knows your history.

The fine print: a "keep taking it" result

This is the part I'd underline twice. Everything above describes what happened while people stayed on the medication. The 88 weeks at the maintenance dose aren't a footnote — they're the condition the whole result rests on. STEP 5 didn't test stopping, so I'm not going to reach for a regain figure from some other study and pretend it belongs to this one. That would be dishonest, and it's a different chapter besides.

The frame that finally made this click for me is the boring one: obesity behaves like a chronic condition, and this looks a lot like chronic-condition treatment. Nobody expects blood-pressure medication to keep working the week after you stop taking it. The two-year data is a staying-on-it story, full stop — and reading it as "the drug fixed me and now I'm done" is the one misread that would set someone up for a hard surprise.

Practically, in the US, that "keep taking it" reality has a cost and a coverage dimension you plan around, not one you wish away. Continued treatment means an ongoing prescription, which means the ongoing conversation with your plan — formulary status, prior authorization, what your coverage looks like a year or two out. That's not a reason to quit; it's a reason to map the long version with your prescriber early, so month eighteen isn't the moment you find out your plan changed its mind.

Where the safety lines sit

I want to lay the safety picture out in tiers, because lumping everything into one scary paragraph is how people end up either terrified or numb. These lines come from the US FDA label for semaglutide (Wegovy); approvals and exact wording differ by country, so treat this as the US version of the map, not the whole world's.

The hard line — an outright no. If you have a personal or family history of medullary thyroid carcinoma (a specific thyroid cancer), or the genetic syndrome called Multiple Endocrine Neoplasia type 2, this drug is off the table. In the US that sits at the label's boxed-warning level and is a flat contraindication — not a "weigh the pros and cons," but a stop.

One notch down — a warning, not a bar. Acute pancreatitis lives on the next tier. It doesn't rule you out up front the way the thyroid history does; instead the label's instruction is to stop the medication and get it checked if pancreatitis is suspected. Different category, and worth keeping straight, because a warning and a contraindication are not the same weight.

The everyday tier — the common company. Then there's the gastrointestinal crowd: nausea, vomiting, diarrhea, constipation. This is the stuff most people actually bump into, and it tends to be loudest early and around dose increases. I'm keeping this qualitative on purpose — the point is to recognize the pattern, not to memorize a frequency.

Three different tiers, three different meanings. The thyroid history is a door that stays shut. Pancreatitis is a smoke alarm — a reason to stop and check, not an automatic no. The GI symptoms are the weather most people learn to read. Flattening all three into one blur is how the genuinely serious line gets lost in the noise.

Bringing this to your own doctor

So, does year two hold? On the strength of STEP 5: for a lot of people who stayed on treatment, yes — a durable, meaningful loss held out to 104 weeks, with the average sitting near 15% below baseline and a majority still down at least 10%. The honest asterisks are the ones I've tried not to bury. The average is a crowd, not a reservation. The result assumes you keep taking it. And the safety lines are real, tiered, and worth knowing before you're two years in.

If you're standing where I was at month twelve, wondering whether to settle in for the long version, the most useful move isn't to decide off a blog post — mine included. It's to take these exact numbers to the person who knows your history, your other medications, and your coverage, and ask what the two-year picture looks like for you specifically. This is published trial data, not a prescription; how it maps onto your body and your plan is a conversation to have with your own clinician.

That's the part no trial can run for you. But at least now you'd walk in knowing what year two actually looked like for the people who stayed.

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