Why am I not losing weight on Mounjaro?

There are lots of reasons for slowed or stalled weight loss on Mounjaro, and being able to figure out what may be causing this can help you make the correct changes to continue with your journey. Working on your diet and exercise usually helps, and in some cases, it’s just more time that’s needed. Here we explore 8 possible reasons for not losing weight on Mounjaro.

1. You need to make changes to your diet

Diet plays a very important role in losing weight with Mounjaro. Not sticking to a healthy diet plan or overeating can reduce weight loss or stop you from losing weight. To lose weight, you should maintain a ‘calorie deficit’. This means eating fewer calories than you burn.

Eating more calories than you burn will lead to weight gain, regardless of whether you’re taking Mounjaro. Remember, Mounjaro helps reduce your appetite so you can eat less without being hungry – it does not make you lose weight on its own.

Guidance on normal calorie intake:

• for people assigned male at birth, the recommended daily calorie intake is 2,500 calories
• for people assigned female at birth, the recommended daily calorie intake is around 2,000 calories

How does a calorie deficit help me lose weight?

Calories are the energy your body gets from food and drinks. Your body uses this energy to carry out daily tasks, exercise, and anything else it needs. If you eat more calories than you use, your body stores the excess as fat, leading to weight gain.

When you eat at a calorie deficit, your body uses its fat reserves for the extra energy it needs, so you lose weight because you're burning fat. By sticking to a calorie deficit, regularly taking your medication and exercising, you should see weight loss results.

While a calorie deficit can help you lose weight, it's important to remember that eating too few calories can also have a negative effect. This can plateau weight loss and make side effects worse. You need to make sure you're getting the right amount of calories and nutrients for safe and effective weight loss.

What to eat on Mounjaro

Here we take a quick look at Mounjaro diet do’s and don’ts. But for more information, our ‘what to eat on Mounjaro’ guide contains lots of helpful advice on nutrition on Mounjaro, including what to eat and what to avoid, especially if you get certain side effects like nausea or gas. In general, it’s good to:

There are apps (like the NHS food scanner) that track calories and nutrition, so you can make sure you’re cutting calories but still getting all the nutrients you need. Here are some quick and easy changes you can make to reduce your calorie intake:

✔ choose reduced-fat options and avoid saturated fats – opt for lean cuts of meat, like reduced-fat mince and use food labels as a guide

✔ choose water and squash instead of fizzy drinks – a regular can of cola can contain as much as 9 cubes of sugar, which is more than the recommended daily limit for adults

✔ reduce your portion sizes – by eating smaller portions, your calories will go down, and you’ll still be able to enjoy your favourite foods

✘ ditch the takeaways – takeaways are packed with calories, and you cannot always tell how many calories your meal contains, while cooking from scratch helps you to know exactly what you’re consuming

✘ stop cooking with oil – oil contains a lot of calories, so by swapping it out for a low-calorie spray, using an air fryer, or ditching it altogether, you can lose more weight and reduce your fat intake

If you make healthier choices and eat smaller portions, you may not need to count your calories as much because you should be losing weight at a safe and steady pace. But, if you find you are not losing weight or are putting on weight on Mounjaro, it’s best to use a calorie tracker until you get the hang of understanding calories and portion sizes.

2. You need to be more active

Physical activity plays another essential part in weight loss. The more your body moves, the more energy it uses and fat it burns. If you’re not as active as you could be, this may be why you’re not losing weight or not losing weight at the rate you’d like. While you may still lose weight without exercising, exercise plays a vital role in helping you build a healthier lifestyle and maintain weight loss after treatment.

The right workout for you

We understand that the idea of exercise can be daunting during a weight loss journey, and we're not saying you need to get up and go for a run straight away. People are at different stages of their fitness journey, and what's achievable for you may not work for someone else. It's important to understand that just doing a little more activity than you're used to can benefit your health and help you lose more weight effectively.

If you've never exercised before:

Start small. Go for a light walk, do some housework or gardening, and then try to increase the amount you do each week. Even if it's just going on a slightly longer walk every day, the more you do, the easier it will be and the better it will feel. You just need to take small steps and stay consistent. It can also help if you feel like you want to snack to do something active instead, even if this is going up and down the stairs in your home a few times or doing some hoovering.

If you're already exercising:

It might be time to start working out more regularly or making your workouts more intense. We recommend a minimum of 30 minutes of cardio (running, cycling, rowing) at least 3 times a week and working your way up to either 150 minutes of moderate-intensity activity or 75 minutes of vigorous-intensity activity a week.

According to NHS guidelines for adults aged 19 to 64, you should aim to:

• do strengthening exercises as well as cardio, such as lifting weights at least 2 days a week
• spread your exercise over 4 or 5 days a week, or every day if you’re more used to exercising or you’re doing shorter bursts
• reduce the amount of time you spend sitting or lying down and break up long periods of sitting down, such as going for a short walk on your lunch break at work or doing some light stretches every few hours if you work on a computer

"Staying active during your weight loss journey always leads to better weight loss results. It also benefits your health in other ways, improving your heart health and cholesterol levels which is especially important for protecting your health now and in the future." Dr Kathryn Basford

3. You need to give Mounjaro more time to work

Weight loss is never an overnight process. That’s why we call it a journey. And while Mounjaro can help you lose an average 22.5% of your body weight on the 15mg maintenance dose, this is over 72 weeks. So, while you may lose weight faster with Mounjaro, it’s still a gradual process. Read more about what to expect on Mounjaro, including how much weight people lose on average per week.

Different bodies, different weight loss

Everyone reacts differently to medication, so some people find they lose weight faster, while others take a while to adjust. There are also other factors that can affect your weight loss journey, like your:

Age

How old you are may affect how you lose weight. It can often be harder to lose weight as you age, especially if your metabolism has slowed down a lot, or you find it more difficult to stay active, and it may take a little more time.

Metabolism

Everyone’s metabolism is different. Some people burn more calories at rest so lose weight more quickly, and others find it harder as their metabolism is slower. If you have a slower metabolism, your weight loss might take a little longer.

Starting weight

If you have a higher starting weight, you might lose weight much faster when you first take Mounjaro. You might also find you lose weight more slowly once you’ve lost some weight. This is normal, and you just need to stick with it.

Lifestyle

People with more active lifestyles may lose weight faster than more sedentary people. If your lifestyle is not very active, it might take you a little longer.

Medications

Certain medications can cause weight gain or make it more difficult to lose weight. You should not stop taking medications you need for this reason, but if you are concerned about this, you should discuss it with your doctor.

Health conditions

Some health conditions make it harder to lose weight and can cause weight gain (such as hyperthyroidism or polycystic ovary syndrome). If you have a condition like this, your doctor will work with you, and you’ll still see results, but it may take a bit longer.

How long will it take to lose weight with Mounjaro?

Everyone loses weight at different rates, but studies into Mounjaro show an average weight loss of:

Month 1: 1 to 3% of body weight.

Month 2: 6% of body weight.

Month 3: 8 to 9% of body weight.

Month 4: 11% of body weight.

Month 5: 12% of body weight.

Average weight loss after 17 months: 16 to 22.5% of body weight.

4. You haven’t reached the highest maintenance dose

Your maintenance dose is the dose of Mounjaro that is most effective for helping you lose weight, but you do not start at this dose. You start at the lowest treatment dose (2.5mg) and slowly titrate until you reach your chosen maintenance dose, which is usually 5mg, 10mg or 15mg.

Mounjaro doses are increased like this to make sure your body safely gets used to the medication and to reduce side effects. You will still lose weight at lower doses and notice the effects of the medication, but you may notice things progress more smoothly once you reach your chosen maintenance dose.

On average, after 72 weeks of treatment, people taking:

• 5mg lost 16% of their weight
• 10mg lost 21.4%
• 15mg lost 22.5%

If you’re not losing weight at the rate you’d like at your starter or a lower dose, we recommend sticking with your treatment until you reach a higher maintenance dose. You may find that this dose works better for you and will notice more weight loss. You can also stay on any maintenance dose, such as 10mg, if you find that you start getting results and do not want to increase your dose again. You can always change your mind and increase it later.

5. You’re in a weight loss plateau

A weight loss plateau occurs when you've been steadily losing weight and then suddenly stop without making any changes to your medication, diet, lifestyle, or exercise plan. This is completely normal and happens to many people during their weight loss journey.

One reason this can happen is that when you first start losing weight, you usually lose more weight faster as you're making significant changes to your diet and starting medication. As you lose weight quickly, your body can kick into 'survival mode'. This is when your body starts storing more calories as fat to make sure you have reserves. When this happens, your weight loss journey slows down, but this is only temporary.

Another cause of a weight loss plateau is water weight. Our bodies are made up of 60% water, and when we introduce exercise, start a diet and make lifestyle changes, we can lose 'water weight' rapidly, but this isn't fat loss. This water is also quickly replaced, so while you may suddenly see a large change on the scales, it could be water weight, and temporary.

This can make it feel like you're losing less weight than you thought or that you're gaining weight, but it's just part of the process. You will still be losing fat, and while losing water weight is temporary, the fat you lose can lead to long-term weight loss if you stick to your routine.

Whatever is causing a weight loss plateau, it's important to remember that it's normal, and there are things you can do to keep your journey going.

What to do in a Mounjaro weight loss plateau:

1. Keep going with your medication: Do not stop taking your medication because you’ve hit a plateau. Keep taking your medication as prescribed and step up to your next dose if it’s time to. You should see your weight loss resume.
2. Adjust your diet: It might be time to change your caloric intake or look at the different foods you're eating. You might find you’ve hit a plateau because you’re eating too much or not enough.
3. Do more exercise: As your body gets used to exercising, you may need to push your limits more. Try increasing how often you exercise or the intensity of the exercise you’re doing.

If you cannot figure out why you’re experiencing a weight loss plateau, or it’s going on indefinitely, you should speak to one of our doctors. They can advise you and discuss your options if you need to make a change.

6. You’re stressed

Your emotions play a large role in weight loss, and stress can impact your journey more than you think. When you’re stressed, your body releases a hormone called cortisol to help protect itself. However, having high cortisol levels over a long period can lead to overeating and your body storing more energy as fat. This is where the term ‘stress eating’ comes from. You get more stressed, so you eat more food as a way to manage and gain more weight.

Studies have also shown that cortisol is linked to storing more fat in your belly. As your cortisol levels go up, so does your blood sugar. When you have higher blood sugar, your body produces more insulin, leading to weight gain. In addition, high cortisol levels can lead to muscle breakdown.

With this in mind, it’s important to check in with yourself to see if your stress levels are stopping you from losing weight as quickly as you’d like.

If you are feeling stressed, you can look into strategies to reduce your stress levels and try to make sure it does not affect your diet plan.

1. Talk to your doctor: If you’re finding your stress levels unmanageable, talk to your doctor. They can help provide mental health support, such as access to Talking Therapies or counselling, which can teach you strategies to cope better.
2. Try relaxation techniques: Introduce some breathing exercises, yoga and mindfulness to your daily routine.
3. Do some activity: Often, going for a short walk or a run can reduce your stress levels.
4. Avoid stress eating: If you’ve already eaten and know you do not need to eat, try not to. It’s much harder to stop stress eating once you’ve started. Pour yourself a large glass of water, and do a breathing exercise before getting something to eat. If you’re struggling with stress eating, speak to your doctor as soon as possible to get the right support.
5. Identify your triggers: Try to find the source of your stress. You can talk to a health professional about this and take steps to reduce your stress better when you know exactly what’s causing it.

You might find that by reducing your stress, you lose more weight.

7. You might have a health condition

There are health conditions that can make it harder to lose weight, but you should not jump to any conclusions before speaking to your doctor.

Health conditions that can affect weight loss include:

• vitamin deficiencies
• hormone imbalances
• depression and chronic stress
• thyroid disorders
• diabetes

How each condition affects weight loss can differ, and you may need more support on your journey or more time to lose weight, but it won’t make it impossible.

If you develop any new symptoms and stop losing weight for a consistent period while taking Mounjaro, you should speak to your GP. They may want to conduct a few tests to ensure another condition isn’t impacting your health or weight loss journey.

> Read more about general reasons why you might not be losing weight.

8. Mounjaro is not right for you

In rare cases, you may not be losing weight with Mounjaro because it’s not the right treatment for you. Everyone reacts to different medications differently, and some medications are more effective for certain people than others. It's also vital to remember that no medication is 100% effective for everyone.

Fortunately, many alternative weight loss medications are available if Mounjaro is not the one for you and our doctors can support you in making a change to something more suitable if required.

Before making a change, closely monitor your progress with Mounjaro and keep a record of your exercise and diet habits. This way, you can be certain that it’s the medication that’s not working for you rather than a problem with your lifestyle or diet.

Alternatives to Mounjaro

If Mounjaro is not right for you, we can prescribe other weight loss medications, including other injections and tablets.

Weight loss injections

Wegovy

Wegovy works in a similar way to Mounjaro but contains a different active ingredient. It makes you feel more full from eating less food, leading to weight loss. It’s an effective medication and very similar in effectiveness to Mounjaro, with an average 21% weight loss after 72 weeks on the 7.2mg maximum dose.

Nevolat

A generic, prescription-only injectable pen, Nevolat works similar to Mounjaro however it is taken daily and contains liraglutide, a different active ingredient. It mimics the GLP-1 hormone which is typically released from your intestines after you eat a meal to tell your brain that you are full, helping to reduce your appetite and cravings. Patients have seen an average 8% weight loss after 56 weeks on the maintenance dose.

Weight loss tablets

Orlistat/Xenical

You take orlistat (generic Xenical) after each meal, which reduces the amount of fat you absorb from that meal. Instead of being absorbed, more fat leaves your body as waste. By eating and absorbing less fat, you lose more weight. It can help 37% of people lose 5% or more of their weight after taking it for 12 weeks.

Mysimba

Mysimba works by reducing your appetite and food cravings. This effect makes it easier to lose weight as you can stick to a lower-calorie diet and feel less hungry. The average weight loss when taking Mysimba is 8.1% after 56 weeks of treatment.

alli

alli works in exactly the same way as Xenical and orlistat, but you do not need a prescription for it. You can get it over the counter, provided the pharmacist thinks it’s safe and suitable. It can help around 46.7% of people lose at least 5% of their weight after 6 months. You should not take alli for more than 6 months.

“You should contact your doctor if Mounjaro is not working at all for you, such as if you’re not getting any appetite suppression, feeling fuller for longer, or losing weight after taking it for a few months. Your doctor will recommend stopping Mounjaro if you’ve not lost 5% of your starting weight by month 6.

You should also contact a doctor if Mounjaro is not working and you:

• are making all the necessary changes to your diet and exercise
• are dealing with stress that you cannot manage on your own
• have any symptoms of an underlying condition, such as thyroid problems
• think you might be pregnant – if there’s a chance you could be pregnant and you’re putting on weight or not losing it, you should take a test straight away as you must not take Mounjaro if you’re pregnant
• are getting side effects
• have missed several doses
• are taking medication that you think might be the cause.” - Dr Kathryn Basford

Does Mounjaro work for everyone?

It’s rare, but Mounjaro does not work for everyone, perhaps because of other health conditions, medication, stress, or simply because the medication is not the right fit. Everybody reacts differently to medication, and now and again a medication does not work as it should, but this does not mean an alternative would not work. However, Mounjaro does work for most people, with 89 to 96% of people losing at least 5% of their weight, depending on which maintenance dose they stayed on.

What shall I do if Mounjaro is not working for me?

If Mounjaro is not working for you, you should speak to your doctor. Make sure you’ve kept a record of your diet, exercise and doses. This will help your doctor understand what’s happening with your treatment and what to do next.

If Mounjaro doesn't work for me, will Wegovy?

It might. Just because Mounjaro did not work or was not the right fit for you, it does not mean Wegovy won’t work. For some people, taking a different active ingredient can help, whether this is because Mounjaro was not causing weight loss or due to side effects.

Before considering switching, it’s important to rule out everything else, like whether your diet or lifestyle could be affecting your weight loss results. If your diet is slowing your weight loss, Wegovy will not work for you either. This is because Mounjaro and Wegovy both work by reducing your appetite and keeping you fuller, but do not cause weight loss on their own.

Can I switch from Mounjaro to Wegovy?

Yes. If you’re not sure if Mounjaro is right for you, you can switch to an alternative medication like Wegovy. We have a service at Asda Online Doctor that makes switching safe and simple.

If you’re already a patient at Asda Online Doctor, you can request a switch by completing a quick health questionnaire in your account. Many of our patients eligible for Mounjaro can also switch to Wegovy, but your doctor will always check to make sure it’s safe and suitable for you before approving your switch.

If you’re new to our services and want to switch from Mounjaro to Wegovy, simply request Wegovy treatment. Then, one of our doctors will review your medical history and confirm if you meet the eligibility criteria.

If your request is approved, your doctor will confirm if the dose of Wegovy you have selected is correct based on your current Mounjaro dose. Even if you are on the highest dose of Mounjaro, you will need to switch to a lower dose of Wegovy and build up the doses to find the dose that works for you. You will need to stop taking Mounjaro for 7 days before starting your first dose of Wegovy. If your request is not approved, we can suggest an alternative option so that you can continue your weight loss journey safely in a way that is best for you.

For more information on switching from Mounjaro to Wegovy, check out our guide.

Why am I gaining weight on Mounjaro?

The most likely reason you're gaining weight on Mounjaro is your diet. If you’re not sticking to a healthy diet or overeating, you can still gain weight. You should also make sure you’re regularly exercising. If you are doing these things, you may have an underlying health condition, or there may be a problem with your dosage. Speak to your doctor if you’re gaining weight on Mounjaro.

Why has my weight loss stalled on Mounjaro?

If your weight loss has stalled on Mounjaro, you may be experiencing a weight loss plateau. This is quite a common thing that happens. You should continue taking your treatment and review your diet and exercise plan. You may also need to discuss changing your dose with your doctor.

Can you lose weight on the Mounjaro 2.5 dose?

Yes. You can lose weight on the Mounjaro 2.5mg dose. According to studies, people can lose around 4% of their body weight during their first 2 months on Mounjaro, which is when you will take the 2.5mg dose.

Why am I not losing weight on Mounjaro 5mg?

Mounjaro 5mg is the lowest maintenance dose and so causes the least weight loss compared to higher maintenance doses. While Mounjaro 5mg can help you lose weight, you might need a higher dose to feel and see the full effects of the medication.

Can you lose weight on Mounjaro without dieting?

Maybe, but not a lot. You might lose some weight on Mounjaro without dieting if you are eating less than before because you have a reduced appetite, or if you’re skipping meals. However, this is not a safe and sustainable way to lose weight, and you’re much more likely to put weight back on when you finish treatment if you do not diet.

When we talk about ‘dieting’ on Mounjaro though, we do not mean reducing calories to the extreme or following fad diets. A Mounjaro diet is a focus on eating healthy, nutritious food and sticking to a safe calorie deficit for weight loss based on your health and fitness levels. This is something you need to continue after stopping Mounjaro, or weight regain is very likely.