No weight loss on Mounjaro? Try these 6 expert tips
Learn what to do if Mounjaro's not working for you. Here are 6 expert tips from the SemaPen team.
Mounjaro is one of the latest injectable obesity treatments. As with similar drugs like Wegovy, it works by mimicking natural hormones that make us feel full, help control food cravings and boost metabolism.
The drug is clinically proven to be safe and effective when prescribed by a healthcare professional. If you take Mounjaro for a full course of treatment and follow medical advice, you can expect to lose around 21% of your body weight.
However, that's an average. Like any medication, Mounjaro can work differently for different people. Your starting weight, your diet and certain medical conditions can all influence how much weight loss you experience.
Seeing no weight loss on Mounjaro is rare. But it's not uncommon for people to wonder if they should be losing more – especially in the first few weeks of treatment.
With that in mind, is there anything you can do to give your weight loss journey a little leg-up?
Absolutely. Here are six tips you can try if Mounjaro's not working the way you expected. They might not all work for you – or even be relevant to your situation. But with a little luck, you'll find just what you need to get your weight loss back on track.
What to do if Mounjaro's not working for weight loss
1. Wait a little longer
Mounjaro is like a marathon runner. It tends to start slowly and then pick up speed as it goes.
This is partly by design. When you join a Mounjaro programme, you're first prescribed a low dose before gradually stepping up to higher doses as your treatment continues. Doctors do this to minimise side effects and help your body get used to the medication.
It's easy to feel downhearted when we don't see results straight away. But if you've only just started taking Mounjaro, you may simply have to wait a little longer for the drug to do its work.
To give you an idea, most users don't notice any weight loss in the first month. You can learn more by reading our guide to Mounjaro weekly weight loss.
2. Switch to a higher dose
Mounjaro's dosing schedule is carefully designed to minimise side effects and help you build up a tolerance to the drug. Most users switch to a higher dose every four weeks until they reach the maximum dose (15mg).
However, this isn't the case for everyone. Some people stick to a lower dose because they find the higher doses difficult to tolerate.
We certainly wouldn't recommend increasing your dose too early. However, if you've stuck to one dose for a while and aren't seeing the results you want, it might be time to consider upping it.
Be sure to speak to your healthcare team first and let them know you're thinking about increasing your dose. If you're on the SemaPen programme, you can get in touch easily using the SemaPen app.
3. Make lifestyle changes
Are you on the right dose? Have you been taking Mounjaro for a while? If you're still not losing weight, you might need to look at what you're eating and your physical activity level.
Remember that Mounjaro isn't a replacement for diet and exercise. We still need to maintain a calorie deficit to lose weight, even while taking drugs like Mounjaro. A calorie deficit happens when we eat fewer calories than we burn.
You don't need to count calories when taking Mounjaro, though some people find it helpful. It's more important to practise good portion control and make healthy choices when selecting and preparing meals.
Maintaining a regular exercise routine can be just as difficult as changing how we eat. You'll find the habit is more likely to stick if you choose a type of exercise you enjoy.
And be careful not to overdo it – you'll only burn yourself out. Instead, it's best to start at a comfortable level and gradually increase the intensity as you get used to it.
4. Push through your weight loss plateau
When Mounjaro starts working, you might notice that you lose lots of weight quite quickly. This is normal. It means your lifestyle changes are working and your body is responding by burning through its fat deposits.
However, it's also common for this steady weight loss to suddenly slow down or stop altogether. This is known as a 'weight loss plateau'.
Weight loss plateaus can occur for a number of reasons. Unfortunately, weight loss can become more challenging over time due to some metabolic adaptation. This is when the body changes how it absorbs and uses energy.
Generally the lighter we are, the fewer calories we need. It can therefore become more difficult to maintain the calorie deficit needed for weight loss. Keeping active and maintaining muscle mass is vitally important to help combat weight loss pleateus.
In any case, weight loss plateaus are temporary and are a normal part of the weight loss process. If you stick it out and stay active, you should see the scales start to drop again.
5. Tell your doctor
If you've ruled out common factors like dosage, diet and exercise, you should let your healthcare team know you're not losing weight on Mounjaro.
That's because there may be a medical reason why you're finding it hard to lose weight. Conditions like insulin resistance, hypothyroidism and polycystic ovary syndrome can contribute to weight gain and make losing weight more difficult.
Another possibility is that you're taking medication that's interfering with weight loss. This can happen with certain antidepressants, antihistamines and blood pressure and blood sugar medications, among others.
In any case, a GP or weight loss professional can provide tailored, expert advice to help you continue your journey on the right foot.
6. Switch to a guided weight loss programme
By helping us control the urge to snack and overeat, Mounjaro can make losing weight much easier. However, it's not a magic wand for weight loss. It still takes hard work and willpower – especially when we hit hurdles that we're not sure how to overcome.
That's why it's so important to choose a planned weight loss programme guided by obesity experts. Unfortunately, with some online pharmacies, this kind of expert guidance is lacking.
If you feel you need more input from your Mounjaro provider, why not consider switching to the SemaPen programme? Unlike most pharmacies, we provide step-by-step support whenever you need it. And our programme is designed by real weight loss specialists, including the former president of the British Obesity & Metabolic Surgery Society.
It's easy to find out if you're eligible. Simply take our online consultation and we'll recommend the best treatment pathway for you.
Sources
1. Jastreboff, A.M. et al. (2022) "Tirzepatide Once Weekly for the Treatment of Obesity" New England Journal of Medicine, 387(3) https://doi.org/10.1056/NEJMoa2206038
This article was reviewed by and approved by Alice Fletcher, Lead Bariatric Dietitian, on
3 April 2025.
