Does two-thirds still apply if I keep the training and the eating habits going?

No trial has measured that version. The extension withdrew the lifestyle intervention at the same moment as the drug, so two-thirds is what happened when the whole package stopped, and it cannot be separated into a drug share and a support share after the fact. What you carry on doing is uncontrolled in that design rather than shown to make no difference.

How fast does it come back?

The extension reports where people were one year out, not a month-by-month curve, so a rate is not something this evidence can give you. Appetite returns as the drug leaves your system, and the weight follows that rather than following a calendar. A predictable slope is the wrong shape of expectation to be holding.

If I restart later, will it work as well as it did the first time?

The extension followed people who stayed off treatment, so it says nothing about restarting. What the trial data do establish is that the appetite effect is present while the drug is, which is the same reason it faded when they stopped. Whether you pick up at your old dose or work back up is a prescriber question, and it is on the list of things worth a call rather than a guess.

Stopping a GLP-1: Appetite Return and Weight Regain

What this page establishes

In the STEP 1 off-treatment extension, participants regained a mean of two-thirds of their prior weight loss within one year of stopping semaglutide 2.4 mg and the lifestyle intervention.
Cardiometabolic variables largely reverted alongside the weight, though weight remained about 5.6% below baseline in the semaglutide arm at one year off treatment.
The extension followed participants from the original 1,961-person STEP 1 randomisation after treatments were discontinued at week 68.
Tirzepatide: 2.5 mg initiation then 5 / 10 / 15 mg weekly maintenance; 16.0% / (10 mg intermediate) / 22.5% mean loss at 72 weeks (SURMOUNT-1).

Quick answers

Does two-thirds still apply if I keep the training and the eating habits going?
No trial has measured that version. The extension withdrew the lifestyle intervention at the same moment as the drug, so two-thirds is what happened when the whole package stopped, and it cannot be separated into a drug share and a support…
Read the full answer
No trial has measured that version. The extension withdrew the lifestyle intervention at the same moment as the drug, so two-thirds is what happened when the whole package stopped, and it cannot be separated into a drug share and a support share after the fact. What you carry on doing is uncontrolled in that design rather than shown to make no difference.
How fast does it come back?
The extension reports where people were one year out, not a month-by-month curve, so a rate is not something this evidence can give you.
Read the full answer
Appetite returns as the drug leaves your system, and the weight follows that rather than following a calendar. A predictable slope is the wrong shape of expectation to be holding.
If I restart later, will it work as well as it did the first time?
The extension followed people who stayed off treatment, so it says nothing about restarting.
Read the full answer
What the trial data do establish is that the appetite effect is present while the drug is, which is the same reason it faded when they stopped. Whether you pick up at your old dose or work back up is a prescriber question, and it is on the list of things worth a call rather than a guess.

Here is the number. In the off-treatment extension of STEP 1, participants regained a mean of about two-thirds of the weight they had lost within one year of stopping semaglutide 2.4 mg and the accompanying lifestyle intervention. Weight remained roughly 5.6% below where it started, so not everything reversed, but most of it did. Cardiometabolic measures largely tracked the weight back up as well. This is the most useful single fact on this whole site and it is usually the last thing people look up rather than the first. Nothing about it means the drug does not work. It means the drug works while it is present, in the same way a blood pressure tablet does.

What the STEP 1 extension measured

STEP 1 randomised 1,961 adults to semaglutide 2.4 mg or placebo alongside a lifestyle intervention, with treatment running to week 68. The extension followed a subset of those participants after both the drug and the lifestyle intervention were withdrawn at week 68, for a further year off treatment.

That design is what makes the result worth taking seriously. It is a planned follow-up of a randomised cohort rather than a survey of people who stopped for their own reasons, so the regain figure is not confounded by whatever motivated an individual to quit.

Timepoint	What happened
Week 0 to 68, on treatment	Mean weight loss around 14.9% on semaglutide 2.4 mg
One year after stopping	Mean regain of about two-thirds of the weight lost
One year after stopping, net	Weight remained about 5.6% below baseline
Cardiometabolic variables	Largely reverted toward baseline alongside the weight

Two-thirds, and the caveats that come with it

Two-thirds is a mean across a group. Individual outcomes spread widely around it, and some participants held far more of their loss than others. Treat it as the base case rather than as your personal forecast.

The second caveat matters more than people notice. The lifestyle intervention stopped too. Participants lost the structured support at the same moment they lost the drug, so the extension measures what happens when the whole package is withdrawn rather than the drug alone. Real-world stopping often looks similar, which is why the figure is still the right reference point.

The residual 5.6% below baseline is real and worth naming. A year after stopping, the group had not returned all the way. That is a modest but genuine persistent benefit.

The honest framing These drugs suppress appetite while they are in your system. They do not reset the weight your body defends. Planning on that basis before you start is a better position than discovering it a year after you stop.

What happened to blood pressure, lipids and glucose

The extension reported that cardiometabolic improvements largely reverted alongside the weight. Blood pressure, lipid measures and glycaemic markers moved back toward where they had been.

This has a direct practical consequence for anyone whose other medications were reduced while they lost weight. If your antihypertensive dose was cut because your readings fell, and the weight comes back, that dose may need revisiting. The same applies to diabetes medication, where doses are frequently reduced when a GLP-1 is added and may need to go back up when it is removed.

That is the strongest reason to tell your prescriber you are stopping, even when the reason for stopping is cost or supply and there is no decision left to make.

Why appetite comes back

The drug does not change your body's defended weight. It suppresses appetite signalling while it is present. When it is withdrawn, that signalling returns, and it returns into a body that has adapted to being lighter with a lower resting energy expenditure and altered leptin and ghrelin signalling.

So the person coming off the drug faces higher hunger against lower energy requirements at the same time. That combination is the physiology of regain, and describing it as a failure of willpower misreads what is happening. It is the same adaptation that makes weight maintained after any substantial loss harder to hold than the same weight in someone who was never heavier.

Body composition does not reverse symmetrically

Lean soft tissue accounted for roughly 40% of the weight lost in the STEP 1 DXA substudy and about 26% in SURMOUNT-1, with a network meta-analysis putting the class average near 25%. None of those trials included a structured resistance-training programme.

Regained weight is not preferentially lean. Someone who loses weight on the drug, stops, and returns to their original number can arrive there with less muscle and more fat than they started with. Repeat that cycle and the effect compounds.

This is the clearest argument for resistance training and adequate protein during the treatment window rather than after it. The lean tissue you keep while losing is the part of the outcome that does not automatically undo itself. Our pages on working out and protein targets cover the evidence on that.

Tapering: widely discussed, not established

Tapering the dose down rather than stopping outright is common practice and common advice. There is no randomised evidence establishing that it reduces weight regain compared with stopping.

That absence does not make tapering wrong. It makes it unproven, and the distinction is worth holding onto when you read confident claims either way. Some prescribers taper for tolerability or for practical reasons around supply. Whether that helps with regain has not been tested in a trial.

Any change to your dose or schedule is a prescriber decision. Do not construct a taper yourself from something you read.

Unproven is not the same as ineffective Where the evidence is silent, this site says so rather than filling the gap. Tapering may turn out to help. Right now no randomised trial has shown that it does.

What can be carried forward

Several things do not evaporate when the drug does. Lean mass preserved through training persists if the training persists. Habits formed around food and activity remain available. Cardiorespiratory fitness gained through exercise stays with you, and randomised data show fitness improved around 10% in exercise arms and did not improve significantly with GLP-1 treatment alone, so that gain is the training's rather than the drug's.

The group in the extension also stayed about 5.6% below baseline a year out. Modest, but the direction is right.

Stopping means losing the appetite suppression rather than losing everything you built while it was there, and what you built is largely down to what you did beyond taking the injection.

If stopping is not your choice

Many people stop because of cost, supply interruption or insurance changes rather than a considered decision. That is common and it is not a personal failure.

Tell your prescriber anyway. The things that need attention are the same: medications that were reduced during weight loss, a plan for what happens as appetite returns, and a realistic conversation about what regain will look like so it does not arrive as a shock.

When to contact a clinician

You are stopping and other medications were reduced during treatment, particularly insulin or blood pressure treatment
Rapid regain accompanied by returning symptoms such as snoring, daytime sleepiness or breathlessness
Distress, shame or a pull toward restricting food after stopping
You are restarting after a long gap and are unsure whether to re-titrate
Any history of an eating disorder, where stopping deserves specific support

If food and weight are difficult for you Regain after stopping is distressing, and for anyone with a restrictive eating history it can be a genuine trigger. Eating disorder support services are the right route for that, and reaching out early is not an overreaction.

Not medical advice

This page reports published trial results. It is general educational information, not advice about whether to stop, continue or taper your treatment. Those are decisions for you and your prescriber together.

The evidence, one row per claim

Claim	Tier	Source
In the STEP 1 off-treatment extension, participants regained a mean of two-thirds of their prior weight loss within one year of stopping semaglutide 2.4 mg and the lifestyle intervention.	established	Wilding et al., STEP 1 trial extension, Diabetes Obesity and Metabolism
Cardiometabolic variables largely reverted alongside the weight, though weight remained about 5.6% below baseline in the semaglutide arm at one year off treatment.	established	STEP 1 trial extension
The extension followed participants from the original 1,961-person STEP 1 randomisation after treatments were discontinued at week 68.	established	STEP 1 trial extension
Lean soft tissue lost during treatment is not automatically regained as lean tissue when weight returns; regain is predominantly fat unless training and protein continue.	emerging	Muscle Mass and GLP-1 Receptor Agonists (Circulation)
There is no randomised evidence establishing that tapering a GLP-1 reduces weight regain compared with stopping.	anecdotal	unsourced
Tirzepatide: 2.5 mg initiation then 5 / 10 / 15 mg weekly maintenance; 16.0% / (10 mg intermediate) / 22.5% mean loss at 72 weeks (SURMOUNT-1).	established	Eli Lilly / NEJM

Sources

Where this comes from

Researched and edited by Thomas Prommer — biohacker, performance athlete, data enthusiast and health coach.

Every number on this page traces to a named source. There are 6 sourced claims below the fold, each with the document it came from.

Sources consulted: Wilding et al., STEP 1 trial extension, Muscle Mass and GLP-1 Receptor Agonists, unsourced, Eli Lilly / NEJM.

Not clinically reviewed. This page was researched and written against primary regulatory and trial sources, and no clinician has checked it.

Sources last read 2026-08-23.

Keep reading

Educational content, reviewed 2026-08-23. Not medical advice, not a prescription, and not a substitute for a clinician who knows your history. Doses named here are label schedules or doses used in named trials, never a recommendation to you.