Mounjaro® Weight Loss by Week: Tips & What to Expect
Key takeaways:
Mounjaro® weight loss by week looks different for everyone.
You might notice less hunger, fewer cravings, and more fullness within the first few days and weeks.
Your weight may gradually drop in the first few weeks. Some people lose about 3.7 kg after three weeks on 5 mg of Mounjaro®.
How much weight you lose depends on your dose, starting weight, and the lifestyle changes you make.
Mounjaro® (tirzepatide) is a once-a-week weight loss injection licensed in the United Kingdom for type 2 diabetes and weight loss.
With Mounjaro® weight loss, weekly progress can vary from person to person, but your hunger levels and weight should steadily go down week by week. You might lose about half a stone by your third week, but this is just an average estimate.
Read on for our guide to Mounjaro® weight loss by week, including what to expect week on week with your weight, side effects, and dose.
Mounjaro® Weight Loss by Week
Here’s what to expect when taking Mounjaro®, looking at the dose you’ll take, the effects on your appetite, weight loss, and common side effects.
Week 1 and 2
Dose
You’ll start on a 2.5-milligram (mg) dose of Mounjaro®. Starting on a low dose that gradually increases gives your body time to adjust to the medication, reducing the chances of side effects.
Effects on Appetite
You might start to feel some of the effects of Mounjaro® within your first week. That can include:
Less hunger
More fullness
Fewer cravings
Don’t worry if this doesn’t happen straight away. As your dose increases, you should start feeling the effects more and more.
Weight Changes
Feeling less hunger and having fewer cravings can help you stick to healthy meals and the right portion sizes, which can promote weight loss. You might start noticing gradual weight loss of about a kilogram (kg) — or a few pounds — in your first two weeks, but this can take a little longer.
Side Effects
When you start taking Mounjaro®, you might experience side effects, such as:
Nausea
Vomiting
Diarrhoea
Constipation
Stomach pain
Side effects tend to be mild or moderate and are common when you first take the medicine. They should gradually get better, though.
Week 3 and 4
Dose
You’ll continue taking a 2.5-mg dose of Mounjaro® in weeks three and four.
Effects on Appetite
By now, you might notice reduced appetite and cravings.
By the third week of Mounjaro® treatment, participants in a 2025 study reported:
Lower appetite
More fullness (satiety)
Fewer cravings — especially for high-fat foods, starchy carbs, and sweets
Less overeating
Less eating in response to stress and anxiety
Participants in this study were taking a 5-mg dose, though, so don’t fret if you don’t notice a difference yet. We all react differently to medications, and you may just need a higher dose to feel the effects.
Focus on healthy habits — like eating a balanced diet, doing movement every day, keeping stress levels low, and getting enough sleep. These habits can help keep your appetite in check and encourage healthy weight loss.
Weight loss your way
Weight Changes
You might start to notice weight loss or continue to lose weight in your third and fourth weeks.
In the 2025 study mentioned above, participants lost an average of 3.7 kilograms — about half a stone — after three weeks of taking Mounjaro®.
How quickly you lose weight on Mounjaro® depends on a few factors, such as:
Your starting weight
When you feel the medication’s full effects on your hunger
The lifestyle changes you make — such as adjustments to eating, exercise, and sleep habits
If you have any medical conditions
Certain medical conditions and medications can make weight loss harder or slower.
Side Effects
You may still experience Mounjaro® side effects during this time, like nausea and vomiting.
Week 5 and 6
Dose
After four weeks at 2.5 mg, you’ll move to a 5-mg dose of Mounjaro®.
Effects on Appetite
Since your dose is now higher, you might notice more appetite suppression.
Weight Changes
Research from 2022 found that participants taking 5 mg of Mounjaro® for four weeks lost an average of roughly 4 percent of their body weight. You might experience less weight loss than this since you’ve been on a lower dose than 5 mg.
If you haven’t noticed any weight loss in your first month, reach out to your GP (general practitioner) or prescribing clinician. They can let you know if you need to make any further lifestyle adjustments or increase your dose after four weeks at the 5-mg dose.
Side Effects
You might experience side effects as your dose increases. This can include nausea and vomiting. Again, these tend to be mild or moderate and should lessen with time.
If Mounjaro® side effects are bothering you, try:
Eating slowly
Eating smaller meals more regularly
Avoiding physical activity after meals
Eating only when hungry and stopping before you get overfull
Let your GP or clinician know if nausea is really bad. They can prescribe anti-nausea medication to help.
Week 7 and 8
Dose
You’ll stay on the 5-mg dose of Mounjaro® during weeks seven and eight.
Effects on Appetite
You should continue seeing a change in your appetite, with less hunger and more fullness. This will likely level out by now.
Weight Changes
After six weeks on Mounjaro®, participants in the 2025 study saw an average weight loss of 7 kilograms, about a stone.
However, they took 5 mg for the first three weeks and 10 mg for three weeks after that — so you may notice less weight loss on a lower dose.
Remember, we all lose weight at different rates, and so many factors affect how quickly you lose weight.
Side Effects
You may continue experiencing side effects, like nausea and vomiting. But you might notice that these gradually get better as your body adjusts to the medicine.
Week 8 and Beyond
Dose
If needed, you’ll move up to a 7.5-mg dose of Mounjaro® after four weeks on the 5-mg dose. Then, your dose could increase every four weeks in 2.5-mg increments if needed. The maximum dose of Mounjaro® is 15 mg.
Your dosage schedule could look like this:
Week 9: 7.5 mg
Week 13: 10 mg
Week 17: 12.5 mg
Week 21 onwards: 15 mg
If you experience side effects, your GP or private provider might keep you on a lower dose longer before increasing it to give you more time to adjust.
Your provider can tell if you need a higher dose, when to increase it, and what dose to take at each stage.
Effects on Appetite
You’ll continue to feel Mounjaro®’s effects on your appetite. This will probably level out by now.
Weight Changes
After eight weeks on Mounjaro®, participants in the 2022 study lost an average of 6 percent of their starting body weight. Weight gradually decreased from there, and higher doses led to more weight loss.
For example, after 72 weeks on Mounjaro® — almost a year and five months — participants taking:
5 mg lost an average of 16 percent of their body weight
10 mg lost an average of 21.4 percent of their body weight
15 mg lost an average of 22.5 percent of their body weight
One thing to note is that weight loss plateaus can happen. A weight loss plateau is when weight loss slows down or stops altogether. It’s normal — even when taking weight loss medicine.
On Mounjaro®, you might hit a weight loss plateau after 24 to 36 weeks.
Stick to your medication schedule and healthy habits, and you should notice further weight loss soon. If you don’t, make small adjustments — like adding an extra strength-training session or increasing your protein intake — to stimulate weight loss again.
Side Effects
You might find side effects have cleared up by now — although they may crop up again if you increase your dose.
Let your prescribing clinician know if side effects are hard to manage. They may recommend lowering your dose of Mounjaro®, or they can prescribe treatments to help.
Unlock your treatment plan
How Much Weight Can You Lose on Mounjaro® Each Week?
How much weight you can lose on Mounjaro® each week depends on many factors, including your dose, your starting weight, and the lifestyle changes you make.
To give you an idea, one study found that participants lost an average of 3.7 kilograms — about half a stone — after three weeks on Mounjaro®. So, you may lose around a kilogram (2.2 pounds or so) each week.
Another study found that participants lost an average of 4 percent of their body weight in four weeks on Mounjaro®. So, you may lose roughly 1 percent of your body weight per week.
Weight loss slows down over time, and it doesn’t always happen at an even rate. You might not lose any weight one week and then lose more weight the next.
Plus, in both studies, participants took a 5-mg dose of Mounjaro®. You’ll probably start on a lower dose that gradually increases to reduce the risk of side effects, which may lead to less weekly weight loss.
Tips to Lose Weight on Mounjaro® Week by Week
To lose weight on Mounjaro® each week and work towards your weight loss goals, focus on eating nutritious foods, doing more movement, getting enough sleep, and lowering stress levels.
Eat Nutritious Foods
There isn’t a strict meal plan to follow when taking Mounjaro®, but you should aim to eat a balanced diet of nutritious food.
That includes:
Fruits and veg
Legumes, like chickpeas, beans, and lentils
Lean protein sources, like chicken, turkey, fish, and tofu
Whole grains, like brown rice, quinoa, wholemeal bread, and oats
Healthy fats, like olive oil, nuts, and avocados
If you find it hard to get enough nutrients on Mounjaro®, try eating smaller meals more regularly. And make sure your snacks are high in protein and fibre.
Also, don’t forget to drink enough water — especially if you have vomiting or diarrhoea. Having a suppressed appetite on Mounjaro® can make it harder to get in enough liquids, so set yourself reminders to sip water or carry a reusable water bottle with you.
Do More Movement
Aim for at least 150 minutes of moderate-intensity activity or 75 minutes of vigorous-intensity activity each week. Also, try to do at least two strength-training sessions a week.
You don’t need to hit those numbers right away. Gradually work up how much physical activity you do as your fitness levels increase.
Outside of your exercise routine, try to stand and move more throughout the day.
Get Enough Sleep
Aim for seven to nine hours of sleep a night.
You can improve your sleep by:
Exercising regularly (but not within 90 minutes of bedtime)
Turning off screens at least an hour before bed
Keeping sleep and wake-up times the same throughout the week
Making your bedroom dark, cool, and quiet
This can keep your hunger levels in check and give you more energy for your workouts.
Lower Your Stress Levels
Stress can spike your appetite and cravings, especially for fatty and sugary foods.
Keep stress as low as possible by:
Reaching out for support from friends, family, or a therapist
Taking time for enjoyable activities and hobbies
Doing breathing exercises, meditation, or yoga
Try not to stress over your Mounjaro® weight loss week by week progress. Weight loss is different for everyone — so while it’s nice to know what to expect, your journey may look different from everyone else’s.
Focus on building healthy habits and enjoying the process of working towards a healthier you.
Mounjaro® Weight Loss by Week: In Summary
When you start a weight loss journey, it’s normal to want to see results quickly. But Mounjaro® isn’t a quick fix, and it’s much healthier to lose weight slowly and steadily.
Here’s a reminder of what you can expect week on week with Mounjaro®:
You might notice appetite changes within a few days. You may have less hunger, more fullness, and fewer cravings. These changes could come on in a few days or take a few weeks to show up as you move up to higher doses.
Weight loss can happen in a few weeks. Everyone’s different, but you may start losing about a kilogram a week. Dose, starting weight, and lifestyle changes can all impact the rate of weight loss.
Side effects are usually front-loaded. Side effects, like nausea and vomiting, typically crop up when you first start Mounjaro® and when your dose increases. They should get better with time.
If you’re considering Mounjaro® or any other weight loss medication, explore your options through the Hers U.K. platform.
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FAQs
See answers to common questions about Mounjaro® weight loss by week.
How much weight will I lose on Mounjaro® in four weeks?
Research shows that participants lose about 4 percent of their body weight after four weeks on Mounjaro®. How much weight you’ll lose depends on your dose, starting weight, how your body reacts to the medication, and the lifestyle changes you make.
How long does it take to lose weight on Mounjaro®?
You may start seeing weight loss in your first few weeks on Mounjaro®. Research shows that people lose about 4 percent of their body weight after four weeks. How long it takes to lose weight depends on your starting weight, your dose, and the lifestyle changes you make, though.
How fast can you lose weight on Mounjaro®?
You may notice weight loss in your first few weeks on Mounjaro®. Slow and steady weight loss is the safest way to lose weight. The National Health Service (NHS) recommends losing 0.5 to 1 kilograms (or 1 to 2 pounds) a week.
This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your GP about the risks and benefits of any treatment.