Folks often ask me what happens if they stop their GLP-1 medication. Some worry about cost or supply, some are tired of the side effects, and some have reached their goal and want to be done.
The honest answer is that, on average, much of the weight comes back after stopping. Blood pressure, blood sugar and lipids (blood fats) tend to drift back with it. Below, I review what the trials show, what may happen to muscle, and how I plan an exit with the patients I treat.
Why the Weight Comes Back
Obesity is a chronic disease, and a GLP-1 medication treats it for as long as you take it. Semaglutide's FDA label says it decreases calorie intake, likely by affecting appetite, and that effect fades once the medication is gone.
Your body also pushes back after weight loss, as one study of 50 people on a 10-week very-low-calorie diet showed. Researchers tracked their appetite hormones, and one year later, several had still not returned to their starting levels. Those changes favored eating more, and the participants still reported more hunger than before they started.
That study used diet rather than medication, but it still shows that the body actively works to regain lost weight. A GLP-1 medication offsets that push while you take it, and the push is still there when you stop.
What the Trials Show When People Stop
Three clinical trials show what happens when patients stop, and although their designs differ, they point the same way.
The STEP 1 trial extension followed adults for one year after their treatment ended. On average, participants in the semaglutide group lost 17.3% of their body weight over 68 weeks before the medication and the lifestyle program both stopped.
One year later, their weight had gone back up by 11.6 percentage points, which is about two-thirds of what they had lost. On average, they ended 5.6% below their starting weight, so some benefit remained.
Results varied from person to person: in the main STEP 1 trial, 86.4% of participants on semaglutide lost at least 5% of their weight. In the extension, 48.2% were still at least 5% below their starting weight one year after stopping.
In STEP 4, 803 adults took semaglutide for 20 weeks and lost 10.6% of their weight on average. Then some continued the medication, and the rest switched to placebo, an injection with no active medication. Over the next 48 weeks, the semaglutide group lost another 7.9%, while the placebo group gained 6.9%. That regain happened even though both groups continued receiving diet and exercise counseling.
In SURMOUNT-4, a similar withdrawal test with tirzepatide, 670 adults first lost 20.9% of their weight on average over 36 weeks. Over the next 52 weeks, the placebo group gained 14.0%, while the tirzepatide group lost another 5.5%. By the end, 89.5% of the tirzepatide group had kept at least 80% of their weight loss, compared with 16.6% of the placebo group.
Your Labs Drift Back Too
The STEP 1 extension also tracked blood pressure, blood sugar and lipids. In the semaglutide group, most of the gains made during treatment faded within a year of stopping. Here are the averages at the start, at the end of treatment and one year after stopping.
Blood pressure: average systolic pressure (the top number) was 129 mmHg at the start and 121 at the end of treatment. One year after stopping, it had risen to 131, back to about where it began.
Blood sugar: A1c is a long-term measure of blood sugar. On average, it went from 5.7% to 5.2% on treatment and was back up to 5.6% a year after stopping. Among participants who started with prediabetes, 93.6% had a normal A1c at the end of treatment, but only 43.3% did one year later.
Lipids: average triglycerides fell from 131.1 to 95.7 mg/dL on treatment and were back up to 122.4 mg/dL a year after stopping.
A1c and several lipid levels stayed a little better than at the start, but most markers moved back toward where participants began.
One thing I check first: did your blood pressure or diabetes medication change while you were on a GLP-1? If it did, tell your physician before you stop, because those numbers can climb back and that medication may need a second look.
What Happens to Muscle
The semaglutide label says the medication causes more fat loss than lean loss, which still means you lose some lean tissue, including muscle. Our article on keeping muscle while losing fat covers that part in detail.
The concern after stopping is what kind of tissue returns. The STEP 1 extension measured weight and labs but not muscle, so that trial cannot tell us how much of the regained weight was fat.
A diet study offers a clue: 78 women past menopause lost weight on a 5-month calorie-cutting program, some with added exercise. They lost 0.26 kg of lean tissue for every 1 kg of fat. Over the following year, they regained only 0.12 kg of lean tissue for every 1 kg of fat that came back.
That study did not involve a GLP-1 medication, so this concern is based on physiology and has not been proven for these medications. If you lose muscle on the way down and regain mostly fat, you could end up near your old weight with less muscle.
How to Stop Well
Some reasons to stop are medical; for example, the semaglutide label says to stop at least 2 months before a planned pregnancy. Others come down to cost, side effects or supply, and each reason calls for a different plan.
1. Decide with your physician: stopping is a medical decision, just like starting, and we make it together after we hear your reason.
2. Plan before your last dose: record your weight, waist, blood pressure and labs on treatment, so we have a baseline for comparison.
3. Protect muscle: keep up your protein intake and your resistance training, both before and after you stop.
4. Recheck after you stop: we repeat weight and labs in the months after your last dose to identify regain early.
5. Choose a path: options include long-term treatment, a physician-supervised step-down, or stopping outright once you know what to expect.
The step-down option now has some clinical trial evidence behind it, from a 2026 trial called SURMOUNT-MAINTAIN. In that trial, 378 adults who had taken tirzepatide for 60 weeks were split into three groups. For one additional year, they continued their full dose, moved to a lower dose, or switched to placebo. Partway through, anyone who regained more than half of their lost weight could go back on tirzepatide.
By the end, the full-dose group was 21.9% below its starting weight on average, the lower-dose group 16.6% and the placebo group 9.9%. The authors noted that individual responses to a lower dose may vary.
From our practice: One patient had been on a GLP-1 for about a year with strong results. He had lost a healthy amount of weight, and his A1c and lipid profile had improved. He asked whether he could cycle off.
We went over the risks and benefits of stopping completely, including the trial data above. Together, we chose a lower dose instead. So far, he has kept the same benefit on the lower dose. That is one patient, and a lower dose does not work for everyone.
What we don't know: STEP 4 and SURMOUNT-4 switched participants to placebo all at once. SURMOUNT-MAINTAIN tested one lower dose of tirzepatide for one year, so none of these trials show how a step-down plays out over many years. We also don't know whether regain levels off below your starting weight, and the STEP 1 extension authors said longer follow-up is needed to tell.
How We Approach It
I plan the exit before you start, so at the first visit we talk about how long treatment might last. We also talk about what stopping would look like, and that plan stays part of our weight management program from day one.
On treatment, we track more than the scale: we follow blood pressure, A1c and lipids through our biomarker testing. Our guide to what your labs should show on a GLP-1 explains what we look for and why.
We also protect muscle the whole way through with protein targets and resistance training, as our article on keeping muscle on a GLP-1 explains. When it is time to stop, we choose the path together and recheck your weight and labs afterward.
Talk to Us Before the Last Dose
If you are thinking about stopping, schedule a visit before your last dose. A step-down is only possible while you are still taking the medication, so once you stop, the choices narrow to restarting or staying off.