Key points
- In SURMOUNT-4, people who switched from tirzepatide to placebo regained 14% of their body weight within a year.
- In the STEP 1 extension, people regained about two-thirds of the weight lost within a year of stopping semaglutide.
- Regain is driven by biology: appetite returns when the medicine stops.
- A planned step-down, protein and strength training help protect results.
What happens when people stop
Two large trials tested what happens when people stop these medicines after losing weight.
| Trial | What was tested | What happened |
|---|---|---|
| SURMOUNT-4 (tirzepatide) | After 36 weeks on tirzepatide, people either continued or switched to placebo for a year. | Those who switched to placebo regained 14% of their body weight. Those who continued lost a further 5.5%. |
| STEP 1 extension (semaglutide) | People stopped semaglutide after 68 weeks and were followed for a year. | They regained about two-thirds of the weight they had lost, and improvements in blood pressure and blood sugar faded too. |
The reason is biological, not a lack of willpower. When the medicine stops, appetite and the body's drive to regain weight return.
Is it a lifelong medicine?
For many people, obesity is a long-term condition, and the WHO's 2025 guideline treats it that way. Some people stay on a maintenance dose long-term; others step down gradually while habits, strength and nutrition carry more of the load. There isn't one right answer, which is why the plan is made with your doctor.
How Lean Life plans a step-down
- 1
Before you stop
Review
Your doctor checks your weight, InBody results, blood tests and how settled your habits are.
- 2
Gradually
Lower dose
The dose comes down in steps rather than stopping at once, where appropriate.
- 3
Throughout
Protect muscle
Protein and strength training continue, because muscle helps keep weight off.
- 4
For months after
Monitor
Regular check-ins catch regain early, when it's easier to act.
What helps keep weight off
- Strength training two or three times a week, to keep muscle.
- Protein at every meal, and regular meal times.
- Weighing yourself regularly, so small changes are caught early.
- Sleep and stress, which both affect appetite.
- Staying in touch with your care team after treatment ends.
Questions
Should I stop once I reach my goal weight?
Talk to your doctor first. Many people need a maintenance dose or a gradual step-down rather than stopping at once.
Can I restart if the weight comes back?
Yes, under supervision. You'll usually restart at a lower dose and step up again to limit side effects.
Will I regain everything?
Not necessarily. Trials report averages; habits, strength training and follow-up make a real difference for individuals.
References
- Aronne LJ et al. Continued treatment with tirzepatide for maintenance of weight reduction (SURMOUNT-4). JAMA 2024
- Wilding JPH et al. Weight regain and cardiometabolic effects after withdrawal of semaglutide: the STEP 1 trial extension. Diabetes Obes Metab 2022
- World Health Organization. WHO issues global guideline on the use of GLP-1 medicines in treating obesity, 1 December 2025
