Maintenance evidence at a glance
Three Phase 3 trials (large human trials with thousands of participants) have tested what happens after a GLP-1 medication is stopped or switched.
| Trial |
Weight loss-phase medication |
Maintenance arm result |
Stopped or placebo arm result |
| STEP 4 (semaglutide) |
Wegovy 2.4 mg for 20 weeks (~10.6% loss) |
Continued Wegovy: a further 7.9% loss over 48 weeks2 |
Switched to placebo: 6.9% regain over 48 weeks2 |
| SURMOUNT-4 (tirzepatide) |
Mounjaro up to 15 mg for 36 weeks (~20.9% loss) |
Continued Mounjaro: a further 5.5% loss; 25.3% total at 88 weeks3 |
Switched to placebo: 14% regain; 9.9% total at 88 weeks3 |
| ATTAIN-MAINTAIN, Mounjaro group |
Mounjaro during SURMOUNT-5 (72 weeks) |
Switched to oral orforglipron: 74.7% of weight loss kept over 52 weeks1 |
Switched to placebo: 49.2% of weight loss kept over 52 weeks1 |
| ATTAIN-MAINTAIN, Wegovy group |
Wegovy during SURMOUNT-5 (72 weeks) |
Switched to oral orforglipron: 79.3% of weight loss kept over 52 weeks1 |
Switched to placebo: 37.6% of weight loss kept over 52 weeks1 |
All four arms also included diet and physical activity support, which contributed to the results above.
Why weight regain happens when you stop an injection
When you’re on GLP-1 medications, the drug helps to maintain lower hunger levels and cravings. It does this by slowing digestion and communicating with the brain’s appetite control centre.
If you stop taking the medication, those effects are removed. If you haven’t developed the healthy habits needed to maintain lower hunger levels naturally, then appetite is likely to return.
Additionally, this effect of returning appetite may be enhanced if you stop taking the medication suddenly, without tapering down the doses gradually.
STEP 4, published in JAMA in 2021, took 803 adults who’d lost an average of 10.6% of their body weight on weekly semaglutide over 20 weeks, then randomised them either to continue semaglutide or switch to placebo for a further 48 weeks.2
People who kept taking Wegovy lost a further 7.9% on average, while those who switched to placebo regained 6.9%, giving a difference of 14.8 percentage points by week 68.2
SURMOUNT-4 did the same experiment with Mounjaro. After 36 weeks on tirzepatide, 670 participants who’d lost around 20.9% of their body weight were randomised to continue or switch to placebo for 52 weeks.3
Those who continued Mounjaro lost a further 5.5%, bringing the total weight loss to 25.3%. Those who switched to the placebo regained an average of 14%, ending with a total weight loss of 9.9%.3
The finding isn’t that GLP-1 medications cause regain when they’re stopped. But these results do show that when you stop taking the medication suddenly, and you don’t develop the habits you need to naturally maintain lower hunger levels, then weight regain is likely.
What the ATTAIN-MAINTAIN trial found
ATTAIN-MAINTAIN is the first Phase 3 trial to test whether an oral GLP-1 medication can be used to support weight maintenance after weight loss is achieved with GLP-1 injections.1
Researchers recruited 376 people who’d completed SURMOUNT-5, a trial that directly compared injectable Mounjaro with injectable Wegovy over 72 weeks.
By the end of SURMOUNT-5, everyone had lost a substantial amount of weight on one of the two injections.
ATTAIN-MAINTAIN asked whether a daily oral medication could support weight maintenance over the next 52 weeks.1
Participants were randomised in a 3:2 ratio to either oral orforglipron at the maximum tolerated dose (24 mg or 36 mg in the trial, broadly equivalent to the approved Foundayo tablet doses) or placebo.
Everyone continued the lifestyle support they’d had during SURMOUNT-5, which included diet and physical activity guidance.1
The results were reported separately for the two groups, based on which injection people had been on:
- Mounjaro switchers (205 participants): orforglipron kept on average 74.7% of the weight loss from SURMOUNT-5, compared with 49.2% on placebo. That’s a treatment difference of 25.5 percentage points. People on orforglipron regained around 5 kg over the year; people on placebo regained substantially more.1
- Wegovy switchers (171 participants): orforglipron kept on average 79.3% of the weight loss from SURMOUNT-5, compared with 37.6% on placebo. That’s a treatment difference of around 42 percentage points. People on orforglipron regained roughly 1 kg over the year.1
43.7% of Mounjaro switchers on orforglipron maintained at least 80% of their original weight loss, compared with 16.4% on placebo.
The Wegovy figures were 55.0% on orforglipron and 6.9% on placebo.1 Improvements in cholesterol, blood pressure, and blood sugar control from SURMOUNT-5 were largely preserved.1
Orforglipron isn’t as potent for active weight loss as injectable Mounjaro.
The earlier ATTAIN-1 trial in adults with obesity or overweight produced an average loss of around 11.2% at 72 weeks, below the 20.2% seen with Mounjaro in SURMOUNT-5.
ATTAIN-MAINTAIN suggests maintaining weight loss may not need a medication as potent as the one that produced the initial loss, especially with sustained habit support.
What this means if you’re coming off Mounjaro or Wegovy
ATTAIN-MAINTAIN adds a new option for someone who’s reached their weight loss goals with Mounjaro or Wegovy.
The existing routes are continuing the injection, stepping down to a lower dose, or coming off and maintaining weight loss without medication support.
Once Foundayo reaches the UK, switching to a daily oral medication will to maintain weight loss will provide another option for patients.
Most people on the maintenance arm of ATTAIN-MAINTAIN still regained some weight (around 5 kg for Mounjaro switchers, around 1 kg for Wegovy switchers), so the realistic goal is to keep most of the loss rather than expecting to keep it all off.1
In ATTAIN-MAINTAIN, everyone on orforglipron continued the diet and physical activity coaching they’d received during SURMOUNT-5.
So the results suggest that combining oral medication with lifestyle changes led to weight maintenance, not the medications on their own.
If you stop the injection and don’t continue to focus on maintaining healthy habits, you have less chance of maintaining weight loss in the long term.
For more on the practical questions around tapering and timing on Mounjaro specifically, see our guide on how long you can stay on Mounjaro, and on Wegovy, how long you can stay on Wegovy.
Maintaining muscle mass through the transition
People who’ve lost 15 to 25% of their body weight on injectable Mounjaro or Wegovy may have lost a share of that weight as muscle and other lean tissue.
Maintaining muscle mass becomes more important during the transition off the injection, when appetite returns, and protein intake can drop.
Three things help maintain muscle mass during weight loss and through the transition into maintenance.
The first is to ensure that you’re eating enough. To maintain a healthier weight in the long term, it’s essential to provide your body with everything it needs to function.
So, while protein and fibre are essential, so are fat and carbohydrate. Eating enough energy to support the function of our essential systems is crucial to support our health and our ability to maintain weight loss in the long term.
The second is eating around 1.2 to 1.6 grams of protein per kg of body weight per day, which is roughly a serving the size of the palm of your hand at each meal. For someone weighing 90 kg, that’s around 110-145 grams of protein daily.
The third is resistance training a couple of times a week. That can be bodyweight exercises (squats, lunges, press-ups), resistance bands, dumbbells, or weight machines.
During the transition off an injection, you’ll gradually lose the support of the medication to lower hunger and cravings. So, it’s essential to maintain the healthy habits that help to keep our hunger lower naturally.
Could the Wegovy pill be used for maintenance?
Theoretically, yes, there’s no reason why you couldn’t use the Wegovy pill for weight-loss maintenance.
The Wegovy pill (oral semaglutide 25 mg) is expected in the UK sooner than Foundayo. See our Wegovy pill guide for more on the medication itself.
Still, there’s no maintenance trial for the Wegovy pill yet.
OASIS 4, published in the New England Journal of Medicine in 2025, tested oral semaglutide 25 mg against placebo for 64 weeks in 307 adults, with the pill arm losing 13.6% of body weight against 2.2% on placebo.5
That’s a result for actively achieving weight loss, not maintaining it after stopping an injection.
ATTAIN-MAINTAIN is the only Phase 3 maintenance trial of an oral GLP-1 medication to date.
A prescriber could consider the Wegovy pill as a step-down from injectable Wegovy on practical grounds (both contain semaglutide), but the dosing and timing differ, and there’s no published trials investigating the use of the Wegovy pill for maintenance.
UK availability and timing
Foundayo (orforglipron) was approved by the U.S. FDA on 1 April 2026 for chronic weight management in adults with obesity, or with overweight and a weight-related condition.6 It hasn’t been approved by the MHRA yet.
Eli Lilly has submitted in more than 40 countries, including the UK, and UK approval is likely in late 2026 or 2027 based on typical timelines.6
After MHRA approval, NICE would need to complete a health technology assessment before NHS access, so private providers would likely offer Foundayo first.
U.S. self-pay pricing launched at around $149 a month for the lowest dose and $349 a month for the highest dose, a useful reference for likely UK private pricing.6
The Wegovy pill is further ahead in the UK pipeline. Novo Nordisk submitted oral semaglutide 25 mg for European and UK regulatory review in the second half of 2025, with approval expected in late 2026.
Until then, the existing UK maintenance options are continuing injectable Mounjaro, continuing injectable Wegovy (now available at both 2.4 mg and the higher 7.2 mg dose, which was MHRA-approved in January 2026), or stepping down to a lower maintenance dose of either injection.
The role of habits in long-term maintenance
Habits and lifestyle are the foundation of maintaining weight loss regardless of the medication.
ATTAIN-MAINTAIN tested orforglipron alongside continued diet and physical activity coaching, so the result is what happens when an oral medication and habit support are combined, not what the medication does on its own.
Think of it as if you were learning to ride a bike. The medication is the stabilisers, but the habits are the bike itself.
Eventually, you might be able to remove the stabilisers and ride your bike without them. But you can’t ride your bike with only your stabilisers.
The weight loss the medication produces gives people a chance to establish new eating patterns, develop a healthier relationship with food, build physical activity into their week, and learn how their body responds to a lower body weight before the medication is removed or stepped down.
The Second Nature programme is built around this principle. We pair medication with structured habit support that supports weight loss maintenance when the medication’s effect reduces, whether that’s maintaining at a lower dose, switching medications, or coming off entirely.
Frequently asked questions
What is ATTAIN-MAINTAIN?
ATTAIN-MAINTAIN is a 52-week Phase 3 trial that tested whether oral orforglipron (Foundayo) could maintain weight loss achieved during a previous injectable GLP-1 trial.1
It’s the first Phase 3 trial of an oral GLP-1 used specifically for maintenance after stopping an injection.
Can a pill maintain weight loss as well as an injection?
In ATTAIN-MAINTAIN, oral orforglipron preserved most of the weight loss participants had achieved on Mounjaro or Wegovy: 74.7 to 79.3% on average vs 37.6 to 49.2% on placebo.1
All participants received lifestyle support throughout the trial.
Is Foundayo available in the UK?
Not yet. Foundayo was approved by the U.S. FDA on 1 April 2026.6
UK approval through the MHRA is likely in late 2026 or 2027, with NHS access following any subsequent NICE assessment.
Is the Wegovy pill approved for maintenance after stopping the injection?
No. The Wegovy pill (oral semaglutide 25 mg) has been tested as a treatment for weight loss in the OASIS 4 trial.5
It hasn’t been tested specifically as a maintenance medication after stopping injectable Wegovy or Mounjaro.
Can I just step down to a lower dose of Mounjaro or Wegovy instead?
Yes, and it doesn’t require waiting for any pill to be approved. Wegovy is available at 2.4 mg and 7.2 mg, with the higher dose MHRA-approved in January 2026.
Mounjaro is available in doses from 2.5 mg to 15 mg, so stepping down to a lower dose is also possible.
The right choice depends on how you’re tolerating the medication, the dose you reached, and what your prescriber recommends.
Why would someone switch from Mounjaro to a pill for maintenance?
The main reasons people consider switching are convenience (a daily tablet rather than a weekly injection) and potentially cost, once UK private pricing for the pills is set.
Switching isn’t a routine clinical decision yet because Foundayo isn’t UK-approved.
Will I regain all my weight if I stop Mounjaro or Wegovy?
Not necessarily. In SURMOUNT-4, people who stopped Mounjaro without continuing any maintenance medication regained around 14% on average, but kept around 10% of their weight loss compared with their starting weight.3
How much regain happens depends largely on the habits built during treatment and on whether maintenance support continues.
How long does Mounjaro or Wegovy stay in the system after stopping?
Tirzepatide has a half-life of around 5 days and semaglutide around 7 days, so both typically clear the body fully over 4 to 6 weeks after the last dose.7,8
Appetite usually returns gradually over this window rather than suddenly. However, this will depend on the habits you’ve developed prior to coming off the medication.
What’s the role of habits if a maintenance pill is coming?
Habits remain the foundation. ATTAIN-MAINTAIN itself paired the maintenance pill with ongoing lifestyle support, and orforglipron is less potent than the injections people were stepping down from.1
The medication makes maintenance easier; the habits make it sustainable in the long term.
Is there a maintenance trial for the Wegovy pill underway?
No published or announced maintenance trial of oral semaglutide 25 mg specifically after stopping an injection has been identified at the time of writing. This is clear evidence of a gap and one to watch as the Wegovy pill reaches the UK.
Can I switch directly from Mounjaro to Foundayo when it arrives in the UK?
That’s a clinical decision for a prescriber to make once Foundayo is available in the UK.
ATTAIN-MAINTAIN supports the broad approach of switching from an injection to oral orforglipron for maintenance, but the right dose and timing for an individual would be set by the clinician.
Take home message
ATTAIN-MAINTAIN is the first Phase 3 trial to show that a daily oral GLP-1 medication can preserve most of the weight loss achieved with injectable Mounjaro or Wegovy when paired with ongoing lifestyle support.1
For UK readers, the practical options today are continuing the injection, stepping down to a lower injectable dose (including Wegovy 7.2 mg, MHRA-approved in January 2026), or coming off with structured habit support.
Second Nature’s published research shows that members on semaglutide combined with structured habit-change coaching achieved an average weight loss of 19.1% at 12 months, with 77.7% achieving at least 10% weight loss.9
Our programme is designed around the balanced plate model (half vegetables, a quarter protein, a quarter complex carbohydrates, plus a serving of fat) and focuses on building habits that support long-term weight loss after the medication ends or the dose is reduced.
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
- Aronne LJ, et al. (2026). Orforglipron for maintenance of body weight reduction: the double-blind, randomized phase 3b ATTAIN-MAINTAIN trial. Nature Medicine.
- Rubino D, Abrahamsson N, Davies M, et al. (2021). Effect of continued weekly subcutaneous semaglutide vs placebo on weight loss maintenance in adults with overweight or obesity: the STEP 4 randomized clinical trial. JAMA, 325(14), 1414-1425.
- 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, 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.
- Wharton S, et al. (2025). Oral semaglutide at a dose of 25 mg in adults with overweight or obesity. New England Journal of Medicine.
- Eli Lilly and Company. (2026). FDA approves Lilly’s Foundayo (orforglipron), the only GLP-1 pill for weight loss that can be taken any time of day without food or water restrictions. Press release, 1 April 2026.
- Electronic Medicines Compendium. (2026). Mounjaro KwikPen 15mg solution for injection in pre-filled pen: Summary of Product Characteristics. Eli Lilly and Company Limited.
- Electronic Medicines Compendium. (2026). Wegovy 2.4mg, solution for injection in pre-filled pen: Summary of Product Characteristics. Novo Nordisk Limited.
- Richards R, Whitman M, Wren G, Campion P. (2025). A Remotely Delivered GLP-1RA-Supported Specialist Weight Management Program in Adults Living With Obesity: Retrospective Service Evaluation. JMIR Formative Research, 9(1), e72577.
