What Happens When You Stop Taking Mounjaro?

Last Updated: 23 September 2026

How to come off Mounjaro

Speak to us before you stop Mounjaro.

Mounjaro is a once-weekly injection licensed in the UK for weight management and for treatment of type 2 diabetes. Mounjaro works by activating GIP and GLP-1 receptors, which are involved in controlling appetite and blood sugar levels. Tirzepatide is the active ingredient in Mounjaro. Once you stop, the amount in your body halves every five days. The effects of stopping Mounjaro develop over several weeks as tirzepatide levels fall.

Two UK sources say different things about coming off Mounjaro. Mounjaro’s prescribing information does not instruct you to reduce your dose before stopping. The NHS takes a different line and advises people not to stop suddenly. A prescriber may suggest reducing your dose gradually instead.

Most people reach a point in their weight loss journey where stopping treatment starts to look like an option. People stop treatment for many practical reasons: 

• reaching their target weight
• side effects 
• cost 
• changing treatment goals 
• plans for pregnancy

People planning a pregnancy should stop Mounjaro at least a month before they start trying to conceive. The prescribing information gives that timeframe because tirzepatide leaves the body slowly. The NHS puts the same advice at four weeks.

Clinicians review your treatment progress after six months at your highest tolerated dose. At that point your prescriber decides whether continuing is right for you if you have lost less than 5% of your starting body weight.

If you take Mounjaro for type 2 diabetes, agree a plan with your diabetes team before taking your last injection. The patient information leaflet warns that blood sugar levels can rise once you stop using Mounjaro.

What to expect after stopping Mounjaro

Appetite can return within a few weeks, and weight regain in SURMOUNT-4 developed over the months that followed.

Time since your last injection	What tends to happen
About five days	The amount of tirzepatide in your body falls by roughly half
The first few weeks	Appetite returns gradually. Common side effects tend to ease
Around four weeks	Almost all of the medication has left your body
The first few months	Weight regain can begin during the months after stopping
One year after stopping	In SURMOUNT-4, the withdrawal group had regained an average of 14% of body weight

The 14% figure is a change in body weight, not a proportion of the weight previously lost.

Appetite may be the first change you notice after stopping Mounjaro. Tirzepatide reduces hunger and makes you feel fuller for longer while you take it. That effect fades as levels of the medicine in your body fall. Some people notice they feel hungry again well before they notice anything on the scales.

Nausea, vomiting, constipation, diarrhoea and stomach pain are the common side effects the NHS lists for tirzepatide. Those effects may ease as the medicine leaves your body. Evidence does not establish how quickly symptoms may settle after a final injection.

Hunger returning after you stop is a different problem from being still hungry on Mounjaro. If you are finding a lack of appetite suppression from your dose, speak to our clinical team for advice.

Do you gain weight back after stopping Mounjaro?

Yes, weight regain was common after stopping shown in SURMOUNT-4, though the amount varied a great deal between individuals.

The SURMOUNT-4 trial followed 670 people on Mounjaro. They had lost an average of 20.9% of their start body weight over 36 weeks. Half carried on with their injections and half switched to a placebo, an inactive treatment given for comparison purposes.

Measure	Continued Mounjaro	Switched to placebo
Weight reduction at week 36, before randomisation	20.9% (all 670 participants)
Weight change from week 36 to week 88	5.5% further loss	14.0% regained
Total weight reduction, week 0 to week 88	25.3%	9.9%
Retained at least 80% of the weight lost in the first 36 weeks	89.5%	16.6%

All figures come from the SURMOUNT-4 treatment-regimen analysis. Everyone took tirzepatide before the trial split them into two groups.

That gap sounds stark on first reading. Both groups finished the trial lighter than they started, and the table sets out the size of the difference between them.

A follow-up analysis of the same trial looked at 308 participants who stopped after losing at least 10% of their body weight. Around 82% regained at least a quarter of the weight they had previously lost within twelve months. About 18% regained less than a quarter.

Individual results varied widely across that range. The trial cannot predict which people regain weight after stopping, or how much they will regain. It reported average weight regain after stopping Mounjaro, not individual outcomes.

Weight regain developed over months in the trial rather than appearing all at once.

What happens to your blood sugar levels?

Blood sugar levels can rise again once treatment ends. That happens whether you take Mounjaro for weight management or for type 2 diabetes. Tirzepatide lowers blood sugar while you take it, and that effect diminishes as the medicine leaves your body.

The follow-up analysis of SURMOUNT-4 tracked what happened next. Average blood sugar, fasting blood sugar and insulin all moved back towards their starting values. The more weight people regained, the further those measures shifted. Participants who regained less than a quarter of their earlier weight loss held onto most of the improvement, with readings at week 88 close to where they stood at week 36.

If you have type 2 diabetes, your GP or diabetes team may need to review your other medication once you stop.

Are there withdrawal effects from Mounjaro?

Mounjaro is not known to cause withdrawal syndrome. The prescribing information lists no withdrawal reactions after stopping tirzepatide. What happens instead is that the effects of treatment fade. 

Losing a treatment effect is not the same thing as withdrawal. Hunger can return, and control over your eating habits may feel harder than it did while you were injecting.

In our experience, patients describe the same sequence. Food noise comes back first, meaning the constant background thinking about food. Portion sizes creep up next, and the weight gain follows.

No trial has measured this – we are describing what patients tell us rather than a documented effect of stopping Mounjaro.

Can I use another weight loss medication instead?

Another weight loss treatment may be an option, and the right choice, depending on why you are stopping Mounjaro. Switching from Mounjaro to Wegovy moves you from tirzepatide to semaglutide. Semaglutide acts on the GLP-1 receptor alone, while tirzepatide acts on both the GIP and GLP-1 receptors.

Staying with weight loss injections means using the Wegovy pen, once a week as before. It keeps a familiar routine and treatment technique.

The Wegovy tablet removes the injection and adds a strict daily routine instead. You take it on an empty stomach, after at least eight hours without food, with no more than 120mls of water. Then you wait thirty minutes before eating, drinking or taking anything else.

Foundayo is the newest option and the only tablet with no food or water rules. It reached UK pharmacies on 24 August 2026 and is available on private prescription. ATTAIN-MAINTAIN followed people who had lost weight on tirzepatide and then stopped. They took either orforglipron or a placebo. Those on orforglipron held onto around 75% of their earlier weight loss, against around 49% on placebo.

ATTAIN-MAINTAIN did not have a group of people who stayed on their injections. That means it cannot tell you whether switching to Foundayo beats carrying on with Mounjaro.

UK prescribing information for these medications does not give a conversion from a Mounjaro dose. Our clinical team looks at the dose you are on now and advises which Wegovy or Foundayo dose suits you best.

A different medicine carries different warnings. Check its own prescribing information rather than assuming the list of people who cannot take Mounjaro carries across.

How can you maintain weight loss after stopping Mounjaro?

Everyone in SURMOUNT-4 kept receiving diet and activity support after stopping, and the group who stopped still regained weight. Regaining weight after stopping does not mean someone has failed at diet or exercise. The trial gave that support to everyone. It did not test whether doing more of it changed the amount regained.

A body composition sub-study of an earlier tirzepatide trial weighed the fat and the muscle separately. About three quarters of the weight lost was fat and about a quarter was lean tissue, much the same split as in people taking placebo. Losing weight on Mounjaro does not cost you more muscle than losing it any other way.

Build your eating and exercise habits while you are still on Mounjaro rather than afterwards. Cravings are easier to manage during treatment, and you can use this time to implement sustainable changes into your lifestyle and eating habits before your appetite returns.

Checking your body weight regularly helps you spot a change early. If you weigh yourself monthly, writing the result down makes the trend easier to see.

We can help you plan the timing, whether you are stopping, switching or thinking about it.

Frequently asked questions

Can I restart Mounjaro after stopping?

Speak to us before you restart Mounjaro after a longer break. The prescribing information covers a missed dose of up to four days. It says nothing about restarting after a longer break (over 3 weeks), so we rebuild your dose rather than resume the one you were on. Side effects are more common while the dose is going up. No trial has followed losing weight a second time round.

Does reducing your dose before you stop help?

No trial has compared reducing your dose first against stopping outright. The NHS still says a doctor may suggest a gradual reduction. Some people prefer to step down to a lower dose for a few weeks before stopping. But whether that changes how much weight you regain is not something the evidence answers.

How long does Mounjaro (tirzepatide) stay in your system?

Tirzepatide levels fall by about half every five days. Most of the medication has gone within four weeks or so. Because tirzepatide levels fall gradually after the final injection, the effect on appetite can fade over several weeks. The length of time Mounjaro stays in your system is why hunger returns over weeks rather than days.

When should I see a doctor?

The symptoms below need attention whether you are still taking Mounjaro or have recently stopped.

Contact our clinical team about:

• questions on stopping, restarting or reducing your dose
• mild nausea, indigestion or bowel changes still settling after your last injection
• low mood, or food and eating taking up more of your thinking after stopping
• uncertainty about whether to switch rather than stop altogether

Contact your GP or call NHS 111 if you notice any of the following:

• increased thirst, passing urine more often, or unusual tiredness, particularly if you also have type 2 diabetes
• headaches, dizziness, weakness or sweating, if you take insulin or a sulfonylurea. Both are diabetes medicines that can lower blood sugar
• yellowing of the skin or eyes, or severe pain in the upper right of your abdomen
• vomiting or diarrhoea severe enough that you cannot keep fluids down

Stop Mounjaro and call 999 or go to A&E if you notice any of the following:

• severe pain in your stomach or back that does not go away
• swelling of the face, lips or throat, or sudden difficulty breathing
• signs of severe dehydration such as confusion or passing very little urine
• thoughts of harming yourself. Go to A&E and ask for the CRISIS team

Key takeaways

• Appetite returns first, usually within a few weeks of the final injection.
• In SURMOUNT-4, people who stopped regained an average of 14% of their body weight within a year. Those who carried on lost a further 5.5%.
• Mounjaro is not known to cause withdrawal symptoms , but the NHS still advises against stopping suddenly. 
• Blood sugar levels can rise again afterwards. Anyone with type 2 diabetes is recommended to discuss discontinuation with their diabetes team before the last injection.
• Switching to oral Wegovy or Foundayo means starting that medicine’s own dose schedule. Our clinical team advises which dose suits you, based on the Mounjaro dose you are on now. 

References

Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity: The SURMOUNT-4 Randomized Clinical Trial, JAMA, 2024 [Accessed 27 August 2026].

Cardiometabolic Parameter Change by Weight Regain on Tirzepatide Withdrawal in Adults With Obesity: A Post Hoc Analysis of the SURMOUNT-4 Trial, JAMA Internal Medicine, 2026 [Accessed 27 August 2026].

Body composition changes during weight reduction with tirzepatide in the SURMOUNT-1 study of adults with obesity or overweight, Diabetes, Obesity and Metabolism, 2025 [Accessed 27 August 2026].

Mounjaro KwikPen solution for injection in pre-filled pen: Summary of Product Characteristics, electronic medicines compendium, 2026 [Accessed 27 August 2026].

Mounjaro KwikPen solution for injection in pre-filled pen: Patient Information Leaflet, electronic medicines compendium, 2026 [Accessed 27 August 2026].

Tirzepatide: a medicine to manage type 2 diabetes and treat obesity, NHS, 2026 [Accessed 27 August 2026].

Wegovy FlexTouch solution for injection in pre-filled pen: Summary of Product Characteristics, electronic medicines compendium, 2026 [Accessed 27 August 2026].

Wegovy tablets: Summary of Product Characteristics, electronic medicines compendium, 2026 [Accessed 27 August 2026].

Foundayo film-coated tablets: Summary of Product Characteristics, electronic medicines compendium, 2026 [Accessed 27 August 2026].

Orforglipron for maintenance of body weight reduction: the double-blind, randomized phase 3b ATTAIN-MAINTAIN trial, Nature Medicine, 2026 [Accessed 27 August 2026]

Eli Lilly launches oral weight-loss drug Foundayo in UK, RTÉ, 2026 [Accessed 27 August 2026]. 

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