What Happens When You Stop Weight-Loss Medication

When people stop GLP-1 weight-loss medicines, most regain a substantial part of the weight they lost. In the two main withdrawal studies, people who stopped semaglutide regained about two-thirds of their lost weight within a year, and people switched from tirzepatide to placebo regained 14% of their body weight over the following year. If you are thinking about skin surgery, this is one of the most important things to understand before you plan it.

This topic is also in our free guide, The Weight-Loss Medication Guide. Get it emailed to you

What the STEP 1 extension found

The STEP 1 trial tested semaglutide against placebo for 68 weeks. In an extension, 327 participants were followed for a further 52 weeks after all treatment stopped (Wilding et al., Diabetes Obes Metab 2022):

The semaglutide group had lost an average of 17.3% of body weight by week 68.
In the year after stopping, they regained an average of 11.6 percentage points, about two-thirds of the weight they had lost.
By week 120, their net change from the start was −5.6%, compared with −0.1% in the placebo group.
Improvements in cardiometabolic measures, such as markers of heart and metabolic health, largely reverted as well.

What SURMOUNT-4 found

SURMOUNT-4 was designed to test withdrawal directly. All participants took tirzepatide for 36 weeks, then 670 were randomly assigned to continue tirzepatide or switch to placebo for a further 52 weeks (Aronne et al., JAMA 2024):

During the first 36 weeks, participants lost an average of 20.9% of body weight.
Between weeks 36 and 88, those switched to placebo regained an average of 14.0% of body weight. Those who continued lost a further 5.5%.
Across the full 88 weeks, average weight change was −25.3% for those who continued and −9.9% for those who stopped.

Both studies point the same way. Those who stopped were still lighter than when they began, on average, but most of the loss did not hold. Individual results vary, and some people maintain more of their loss than others.

Why the weight comes back

These medicines work by reducing appetite and slowing stomach emptying (healthdirect). When the medicine is withdrawn, those effects wear off and appetite returns. healthdirect is direct about this: weight-loss medicines do not cure obesity, and healthy habits need to continue after treatment. For more on why the body defends its weight, see why we gain weight and keeping the weight off.

Why this matters for planning skin surgery

Body contouring removes skin and tissue to fit the body you have at the time of surgery. If weight is regained afterwards, the result can be affected. Three points from the published literature are relevant:

Stable weight lowers complications. In one cohort study, a stable weight for at least 3 months before body contouring significantly reduced complications (van der Beek et al., Obesity Facts 2011). A review recommends 4–6 months without weight fluctuation (Giordano, Open Access Surgery 2015).
Medication timing is different. A 2025 review suggests contouring may be appropriate after about 8–12 months of semaglutide use once weight has plateaued, but advises caution because of regain when the medicine is stopped (Garbaccio et al., Aesthetic Plast Surg 2025).
Your plan for the medicine matters. A weight that is stable while on treatment may not be stable if you later stop. Your surgeon needs to know whether you intend to continue, reduce or stop, and that decision belongs with your prescribing doctor.

For a fuller discussion of timing, see when is the right time for skin removal.

Questions to raise with your doctors

With your prescribing doctor: Is the plan to continue long term, reduce, or stop? If stopping, how will weight be monitored, and what support is in place?
With your dietitian: How much protein do I need, and how should training change to protect muscle? See protein and muscle and Amy Kellner APD.
With your surgeon: How long should my weight be stable before surgery, given my medicine plan? What happens to the result if my weight changes afterwards?

Do not stop or change a weight-loss medicine in order to qualify for surgery, or for any other reason, without talking to your prescribing doctor first.

Where to next

If your weight has been steady for several months and loose skin is now the main issue, book a consultation with Dr Kumar or take the readiness assessment to see where you stand.