What happens when you stop Mounjaro or Wegovy?
On average, half to two-thirds of the weight lost came back within a year. But not for everyone. About 1 in 6 who stopped Mounjaro in one trial kept most of it off.
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What happens when you stop Mounjaro?
For most people, weight starts to come back. In trials, about half to two-thirds of the weight lost had returned a year after the last dose.
In one trial, people lost 20.9% on Mounjaro in 36 weeks. Those then switched to a dummy injection (a placebo) were 9.9% below their start a year later. So about half had come back.
Wegovy looked much the same. A year after stopping, people had regained two-thirds of the weight they lost.
| Group in the trial | Lost on the medicine | A year after stopping |
|---|---|---|
| Stopped Mounjaro at week 36 | 20.9% | 9.9% below their start |
| Stopped Wegovy at week 68 | 17.3% | 5.6% below their start |
| Kept taking Mounjaro to week 88 | 20.9% by week 36 | Still on it: 25.3% below their start |
Sources: SURMOUNT-4; STEP 1 extension
In the Mounjaro trial, diet and activity advice carried on after the switch. In the Wegovy trial, that support stopped too.
It isn’t only weight. Gains like lower blood pressure and blood sugar faded as well. For weight medicines in general, they were projected to be back where they started within 1.4 years.
So if you’re thinking of stopping, plan it with your prescriber first.
How fast does weight come back after stopping Wegovy?
About 0.8 kg a month, on average. That comes from a 2026 review of studies on semaglutide (Wegovy) and tirzepatide (Mounjaro), which tracked weight after the last dose.
People had lost 14.7 kg on average when they stopped. About 9.9 kg of it came back in the first year.
| Time since last dose | Weight back | Still off |
|---|---|---|
| At the last dose | 0 kg | 14.7 kg |
| Each month after | About 0.8 kg | Less each month |
| 1 year | About 9.9 kg | About 4.8 kg |
| 1.5 years (a forecast) | All of it | About 0 kg |
Source: BMJ 2026 review
The 1.5 years is a forecast. The studies followed people for up to 12 months after stopping these two medicines.
Weight came back faster than after a diet programme. After weight medicines in general, it was projected back to the start in 1.7 years. After diet programmes, it was projected at 3.9 years.
So weigh yourself once a week after you stop, to spot a change early. The weight loss percentage calculator turns it into a percentage.
Does everyone regain weight after stopping Mounjaro?
No. That’s the 1 in 6 from the top of this page. A year after stopping, 16.6% had kept at least 80% of the weight they lost.
Source: SURMOUNT-4
The trial doesn’t say what the 1 in 6 did differently. So no one can promise which plan makes you one of them.
What NICE does say is that people stopping weight medicines should be offered support to keep the weight off. Ask for it.
How to stop Mounjaro or Wegovy safely
Talk to your doctor first, and don’t stop suddenly. If you have type 2 diabetes, the NHS says stopping could affect your blood sugar. Your doctor may suggest lowering your dose gradually.
Stopping, step by step
- 1
Talk first
Tell your prescriber you want to stop.
- 2
Agree how
Your doctor may lower the dose gradually.
- 3
Ask for support
NICE says you should be offered help to keep weight off.
- 4
Keep weighing
Once a week, same day and time.
Sources: NHS: tirzepatide; NHS: semaglutide; NICE NG246
Planning a baby? The NHS says to stop Mounjaro at least 4 weeks before you start trying. For Wegovy, it’s at least 2 months.
On the NHS, Wegovy is used for a maximum of 2 years, in a specialist weight service. If that’s you, ask early what support comes after.
Lost under 5% after 6 months on the highest Mounjaro dose you can manage? NICE says to decide whether to carry on. For Wegovy, NICE says to consider stopping below 5% after 6 months.
Never stop or change a prescribed medicine without your prescriber.
How to keep weight off after Mounjaro
Five things to do after your last dose
- Ask your prescriber or weight service for support to keep the weight off.
- Eat a balanced diet for the long term, using the NHS Eatwell guide.
- Build up your activity. People who have lived with obesity and lost weight may need 60 to 90 minutes a day to avoid regaining it.
- Weigh yourself once a week, on the same day and at the same time.
- If the medicine lowered your blood pressure or blood sugar, ask your GP when to check them again.
Sources: NICE NG246: medicines; NICE NG246: activity and diet
60 to 90 minutes sounds a lot. NICE counts everyday activity, like brisk walking, gardening or cycling.
Want ideas? See the best exercise for weight loss and how to keep muscle while losing weight.
For blood checks, see blood tests on Mounjaro and blood tests on Wegovy.
When to speak to a GP
Talk to your GP or prescriber if:
- You want to stop Mounjaro or Wegovy. Don’t stop suddenly, especially if you have type 2 diabetes.
- You want to get pregnant. Stop Mounjaro at least 4 weeks, or Wegovy at least 2 months, before you start trying.
- Your weight is climbing back after stopping and you want help to keep it off.
- Call 111 if you have severe pain in your stomach or back that doesn’t go away, or severe tummy pain. These can be signs of an inflamed pancreas or gallstones.
- Call 111 if you think you’re having any other serious side effect.
Call 999 if you think you’re having a severe allergic reaction. Signs include your lips, mouth, throat or tongue suddenly swelling, struggling to breathe or swallow, a tight throat, or wheezing. Other signs are your skin, tongue or lips turning blue, grey or pale, suddenly feeling very confused, drowsy or dizzy, or fainting.