Use our free Weight Regain Prevention Planner
Whether you’re planning to stay on Mounjaro long-term or thinking about coming off in the future, our free planner shows where your habits sit now and what to focus on.
It assesses the 8 habits that most strongly predict whether weight loss is maintained: diet quality, protein, meal planning, aerobic exercise, strength training, emotional eating, sleep, and stress.
The tool shows you which habits are already in place and which still need work, then generates a personalised plan. It takes around 3 minutes and is based on the same evidence and approach we use in our medication-supported programme.
If you select ‘staying on long-term’, the gap analysis still runs, so you can see where to focus while you’re on the medication.
How long should I stay on Mounjaro?
How long you stay on Mounjaro depends on your weight loss goals, how well you tolerate the medication, and whether you’re accessing it privately or through the NHS.
The SURMOUNT-1 trial showed that after 72 weeks on tirzepatide 15 mg, participants lost an average of 20.9% of their body weight.1
The SURMOUNT-4 trial extended this to 88 weeks, with participants who continued on the medication reaching an average total weight loss of 25.3%.3
Most people who reach their target weight do so within 1 to 2 years.
After that, the decision is whether to continue on Mounjaro, step down to a lower dose, or work with your prescriber to come off gradually while focusing on the habits you’ve built.
What the research tells us
| Duration |
What to expect |
Key consideration |
| 0 to 12 weeks |
Initial weight loss begins; side effects most common |
Focus on building habits alongside medication |
| 12 to 36 weeks |
Significant weight loss (average 15 to 21%) |
Reach maintenance dose; monitor progress |
| 36 to 72 weeks |
Continued weight loss, approaching plateau |
Discuss long-term goals with the prescriber |
| 72 to 88 weeks |
Weight loss plateaus (average 22 to 26%) |
Continue, step down, or transition off with habit support |
| 88+ weeks |
Maintenance phase for most people |
Same as above |
How long will I continue to lose weight on Mounjaro?
Weight loss with Mounjaro typically plateaus after around 18 months on the highest tolerated dose.
The average weight loss at this point is around 22 to 26% of starting body weight, though individual results vary. Some people lose 10 to 15%, while others reach 30% or more.1,3
A 2025 post-hoc analysis of the SURMOUNT trials found that the time to reach a weight plateau varied by starting BMI.
Those with class II or III obesity (BMI 35+) typically plateaued around 36 weeks, compared to around 24 to 26 weeks for those with overweight or class I obesity.4
The amount of weight you lose isn’t down to the medication alone. The eating patterns, activity levels, and stress and sleep habits you build while taking Mounjaro all contribute.
Can I stay on a lower maintenance dose?
Yes. Many people who reach their goal weight choose to step down to a lower dose rather than continue at the maximum or stop completely.
The licensed maintenance doses for Mounjaro in the UK are 5 mg, 10 mg, and 15 mg.5
The 2.5 mg, 7.5 mg, and 12.5 mg strengths are titration doses and aren’t licensed as long-term maintenance, though prescribers may sometimes use them off-label for maintenance based on individual response. Discuss this with your clinician.
Staying on a lower dose is a practical middle ground for many people. It can keep hunger lower without the cost or side effect profile of the maximum dose.
The decision about maintenance dosing should be made with your prescriber based on:
- How much weight you’ve lost
- Whether your appetite returns at lower doses
- Any ongoing side effects
- Your long-term weight maintenance goals
- Cost
What does long-term Mounjaro cost?
Cost is a real factor in how long you can realistically stay on Mounjaro privately.
UK private prescription prices vary by provider and dose, but a year on a maintenance dose typically costs in the region of £2,000 to £3,000. Two to three years of continuous use can add up to £4,000 to £9,000 or more.
This is worth weighing against the cost of weight regain. If stopping the medication leads to gradual regain, and that regain affects your health (blood pressure, blood sugar, joint pain, sleep apnoea), the comparison isn’t medication cost vs no cost: it’s medication cost vs the cost of treating regained weight and its consequences.
It’s also why building habits while on the medication is crucial. The stronger the habits you have in place, the lower the chance you’ll need to restart the medication later.
Reasons you might need to pause or stop Mounjaro
Some decisions about how long to stay on Mounjaro aren’t about weight loss progress at all. Three situations that often come up:
Surgery or general anaesthesia
GLP-1 medications slow gastric emptying, which can increase the risk of food being retained in the stomach during anaesthesia.6
UK consensus guidance from the Association of Anaesthetists and the Royal College of Anaesthetists recommends pausing weekly GLP-1 medications, including Mounjaro, for 1 week before elective surgery requiring sedation or general anaesthesia.6
Tell your surgical team well in advance of any planned procedure that you’re on Mounjaro.
For emergency surgery, the anaesthetic team will manage the risk on the day. There’s no need to delay urgent care because of the medication.
Pregnancy planning or pregnancy
Mounjaro isn’t recommended during pregnancy. The UK Summary of Product Characteristics advises that women planning to conceive should stop Mounjaro at least one month before trying.5
Mounjaro can also reduce the effectiveness of oral contraceptives during the first weeks of treatment and after each dose increase, due to delayed gastric emptying.
The MHRA recommends switching to a non-oral contraceptive method (such as an IUD, implant, or injection) or adding a barrier method (such as condoms) for 4 weeks after starting and after every dose escalation.5,7
If you discover you’re pregnant while taking Mounjaro, contact your prescriber immediately.
Persistent or significant side effects
Most side effects of Mounjaro are mild to moderate gastrointestinal symptoms during dose escalation.
In SURMOUNT-1, adverse events led 4.3% to 7.1% of participants to discontinue tirzepatide, depending on dose.1
If side effects persist and don’t resolve, your prescriber may suggest reducing the dose, pausing, or stopping entirely. This isn’t a failure of the medication: it’s a clinical decision based on benefit and tolerability.
What happens when you stop Mounjaro
When you stop Mounjaro, your appetite gradually returns to its previous levels as the medication clears your system, unless you’ve built habits that help to manage hunger levels naturally. This typically takes 3 to 5 weeks because tirzepatide has a half-life of around 5 days.5
The SURMOUNT-4 trial measured what happens when people stop Mounjaro after significant weight loss.3
After 36 weeks on tirzepatide, participants had lost an average of 20.9% of their body weight. They were then randomised to either continue Mounjaro or switch to a placebo. After another 52 weeks (88 weeks total):
- Those who continued Mounjaro lost an additional 5.5%, reaching 25.3% total weight loss
- Those who stopped regained an average of 14% of their body weight, ending at 9.9% total weight loss
A 2025 post-hoc analysis added important detail. Among those who stopped, the people who regained 25% or more of their lost weight also lost most of their early improvements in waist circumference, blood pressure, cholesterol, and blood sugar regulation. Those who regained less than 25% of their weight kept most of their other health improvements.8
In other words, the cardiovascular benefits track closely with the weight kept off. A slower taper combined with habit work makes more of a difference than how quickly you actually stop.
After 88 weeks, the group that stopped had still kept around 10% weight loss, which is clinically significant. But the trajectory was a continued regain over time.
For the full tapering protocol and habit work that support a smooth transition off Mounjaro, see our dedicated guide on coming off Mounjaro.
NHS vs private prescription duration
There’s an important difference between NHS and private prescriptions when it comes to how long you can take Mounjaro.
NHS prescriptions
NICE approved Mounjaro for managing overweight and obesity in December 2024 (TA1026), with the guidance most recently updated in September 2025.2
NICE recommends reviewing treatment if less than 5% of body weight has been lost after 6 months on the highest tolerated dose.
Treatment can continue beyond that point if it’s working, in line with the recognition of obesity as a chronic condition that may need long-term care.2
NHS England’s interim commissioning guidance is rolling Mounjaro out in phases over 3 years, prioritising those with the highest clinical need (BMI 40+ with multiple weight-related conditions).10
Private prescriptions
If you purchase Mounjaro privately, there’s no fixed time limit. You can continue taking the medication for as long as:
- It remains medically appropriate
- You tolerate it well
- Your prescriber approves continued use
Frequently asked questions
Is Mounjaro a lifelong medication?
It can be, but it doesn’t have to be. Some people take Mounjaro long-term to maintain their weight loss.
Others use it for 1 to 2 years to reach their goals and then transition off while keeping their results through habits.
Current clinical guidance treats obesity as a chronic condition that may need long-term treatment for some people.2
Will I regain all the weight if I stop Mounjaro?
Not necessarily. In the SURMOUNT-4 trial, participants who stopped Mounjaro after 36 weeks regained around 14% of their body weight over the following year, but still kept around 10% weight loss compared to baseline.3
The strength of your habits at the point of stopping makes a meaningful difference.
How long does Mounjaro stay in your system after stopping?
Tirzepatide has a half-life of around 5 days, so it takes approximately 25 to 30 days to clear your system fully.5 Your appetite typically returns gradually over this period.
Can I stay on a lower dose once I reach my goal weight?
Yes. Many people transition to a lower licensed maintenance dose (5 mg or 10 mg) once they’ve reached their goal. This can help maintain results while reducing cost. Discuss the right dose for you with your prescriber.
Should I taper off or stop suddenly?
There’s no published clinical guideline mandating tapering for Mounjaro, because the medication doesn’t cause withdrawal.
The reason most prescribers recommend a gradual reduction is behavioural rather than pharmacological: stepping down gives you time to monitor how your appetite changes at each stage and to bed in the habits you’ll rely on once the medication is out of your system.
Can I restart Mounjaro if I regain weight?
Yes, in most cases, you can restart Mounjaro after stopping. You typically start again at the lowest dose (2.5 mg) and titrate up, following the same schedule as when you first started. Discuss this with your prescriber.
Do I need to stop Mounjaro before surgery?
For elective surgery requiring sedation or general anaesthesia, UK consensus guidance recommends pausing weekly GLP-1 medications, including Mounjaro, for one week before the procedure.6 Tell your surgical team about your medication well in advance.
Can I take Mounjaro if I’m planning to get pregnant?
No. The UK Summary of Product Characteristics advises stopping Mounjaro at least one month before trying to conceive.5
Mounjaro can also reduce oral contraceptive effectiveness during titration, so a non-oral or barrier method is recommended for 4 weeks after starting and after each dose increase.
How do I work out the right maintenance dose for me?
The right maintenance dose depends on how well you maintain your weight at different doses, any side effects, and your long-term goals. Most prescribers find this through gradual adjustment rather than picking a dose upfront.
Take home message
There’s no fixed time limit on how long you can take Mounjaro privately. Most people reach their weight-loss goals within 1 to 2 years, after which they can continue at a maintenance dose, step down, or transition off with habit support.
The SURMOUNT-4 data shows that continuing Mounjaro maintains and slightly extends weight loss, while stopping leads to some regain, with the cardiovascular benefits tracking closely with the weight kept off.
The amount of regain varies, and the strength of your habits at the point of stopping is the biggest modifiable factor.
The eating patterns, activity habits, and coping strategies you build while on Mounjaro shape what happens after. Surgery, pregnancy planning, side effects, and cost are all valid reasons to pause or stop, separate from weight loss progress.
If you haven’t already, scroll back up and use our Weight Regain Prevention Planner to see where your habits sit and what to focus on.
Second Nature's Mounjaro and Wegovy programmes
Second Nature provides Mounjaro or Wegovy as part of our Mounjaro and Wegovy weight-loss programmes.
Why choose Second Nature over other medication providers, assuming you're eligible?
Because peace of mind matters.
We've had the privilege of working with the NHS for over eight years, helping people across the UK take meaningful steps toward a healthier, happier life.
Our programmes are designed to meet people where they are, whether that means support with weight loss through compassionate one-to-one health coaching, or access to the latest weight-loss medications (like Mounjaro and Wegovy) delivered alongside expert care from a multidisciplinary team of doctors, psychologists, dietitians, and personal trainers.
At the heart of everything we do is a simple belief: real, lasting change comes from building better habits, not relying on quick fixes. We're here to support that change every step of the way.
With over a decade of experience, thousands of lives changed, and a long-standing record of delivering programmes used by the NHS, we believe we're the UK's most trusted weight-loss programme.
We hope to offer you something invaluable: peace of mind, and the support you need to take that first step.
References
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- Jastreboff AM, Aronne LJ, Ahmad NN, et al. (2022). Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine, 387(3), 205-216.
- National Institute for Health and Care Excellence. (2024, updated 2025). Tirzepatide for managing overweight and obesity (TA1026).
- Aronne LJ, Sattar N, Horn DB, et al. (2024). Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity: The SURMOUNT-4 Randomized Clinical Trial. JAMA, 331(1), 38-48.
- Horn DB, Kahan S, Batterham RL, et al. (2025). Time to weight plateau with tirzepatide treatment in the SURMOUNT-1 and SURMOUNT-4 clinical trials. Clinical Obesity, 15(3), e12734.
- Electronic Medicines Compendium. (2026). Mounjaro KwikPen 15mg solution for injection in pre-filled pen — Summary of Product Characteristics. Eli Lilly and Company Limited.
- El-Boghdadly K, et al. (2025). Elective peri-operative management of adults taking glucagon-like peptide-1 receptor agonists, glucose-dependent insulinotropic peptide agonists and sodium-glucose cotransporter-2 inhibitors: a multidisciplinary consensus statement. Anaesthesia.
- Medicines and Healthcare products Regulatory Agency. (2025). GLP-1 medicines for weight loss and diabetes: what you need to know. GOV.UK, 5 June 2025.
- Horn DB, Linetzky B, Davies MJ, et al. (2025). 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.
- Richards R, Lunt W, Whitman M, Spaltro G, Hall R. (2025). Semaglutide and Tirzepatide in a Remote Weight Management Program: 12-Month Retrospective Observational Study. JMIR Formative Research, 9, e81912. doi:10.2196/81912.
- NHS England. (2025). Interim commissioning guidance: implementation of NICE TA1026 for tirzepatide.
