Yes, it is safe to switch and you can switch from Mounjaro to Wegovy if a doctor approves that you are eligible and if it is suitable for you. If you are already eligible for Mounjaro it is likely you will also be eligible for Wegovy but our doctors will always check if a treatment is right for you. You will always need to wait 7 days between your last Mounjaro dose and your first Wegovy dose. Please note that when switching using our dose conversion guide, you may not experience the same effect (which can improve with dose titration), as the treatments are not necessarily medically equivalent.

New to our service?

You will need to make a patient account and request treatment for Wegovy by filling in a short questionnaire. One of our doctors will review this and check if you are eligible and if it is suitable and safe for you to take.

Already with us?

Switching is simple if you already have an account with us. Just request Wegovy via a health questionnaire. This will let us know that you would like to switch. It is likely that you will be eligible for Wegovy if you are already eligible for Mounjaro, but our doctors will always check if Wegovy is right for you.

If your treatment for Wegovy is approved, switching is straightforward:

1. Dose confirmation – your doctor will suggest a starting dose of Wegovy based on your current Mounjaro dose, and whether you’ve had any side effects
2. Stop taking Mounjaro after your final injection – you can stop straight away if you no longer want to take it, or you might choose to finish your medication first so as not to waste it.
3. Wait 7 days before starting Wegovy – this makes sure it’s safe to start taking Wegovy.
4. Start Wegovy – take your dose of Wegovy when you would expect to take your next dose of Mounjaro, 7 days after the last one.
5. Increase your dose gradually over several weeks if you want to, just as you may have done with Mounjaro.

Wondering how doses between Mounjaro to Wegovy work? Here is a dose conversion guide for more information:

Before you make the switch, your doctor will check that you:

• are not pregnant or breastfeeding
• have not had serious side effects from Mounjaro, like pancreatitis or a severe allergic reaction (this could make Wegovy unsuitable too)
• are not allergic to semaglutide (the active ingredient in Wegovy)

If you’re eligible for Mounjaro, you’re very likely to be eligible for Wegovy – but it’s always important to confirm. You may be able to switch even if you've reached a healthy BMI of 25 or lower.

What can I expect during the switch?

Your doctor will choose the dose that’s right for you. You won’t need to go back to the very lowest dose, but it’s important to start on a dose your body can manage.

You might notice your appetite feels a little stronger at first, this is normal and should settle as your treatment is adjusted.

Some people get mild side effects when changing medications, but these usually improve as your body gets used to Wegovy.

Both Mounjaro and Wegovy are injectable weight loss medications taken once a week. They contain active ingredients that act on glucagon-like peptide-1 (GLP-1) receptors in your body, helping to:

• reduce your appetite
• keep you feeling full for longer
• lower your blood sugar levels
• support healthy eating and lifestyle changes

Mounjaro contains tirzepatide, which works on 2 hormones: GLP-1 and glucose-dependent insulinotropic polypeptide (GIP), while Wegovy contains semaglutide, which works on GLP-1 alone. The result is similar, it becomes easier to eat less and lose weight over time.

Cost

Generally, Mounjaro is more expensive than Wegovy. So, if you’re looking for a more cost-effective weight loss option, Wegovy may be more suitable for you. If you’re currently using Mounjaro and you’re concerned about the cost, we’re here to help. We’ve updated our processes for switching from Mounjaro to Wegovy, which makes it easier to switch, with less disruption to your treatment.

Other reasons for switching

Other reasons you might decide to move from Mounjaro to Wegovy because of:

• availability – one medication may be easier to get hold of than the other, as there are sometimes stock shortages due to the popularity of weight loss injections
• side effects – you may tolerate Wegovy better than Mounjaro if you’re getting unmanageable side effects from Mounjaro
• weight loss results – if you’ve not seen the results you hoped for with Mounjaro, switching may help
• doctor’s advice – your healthcare provider may recommend Wegovy for your individual needs

Not getting the results on Mounjaro?

Studies show Mounjaro can lead to slightly greater weight loss than Wegovy at the highest dose — around 22.5% after 72 weeks, compared to 20% after 68 weeks with Wegovy. But weight loss is different for everyone. Some people may see better results with Wegovy: almost a third of people in its trial lost 25% or more of their starting weight after a year on the maximum 7.2mg dose.

Clinical benefits of Wegovy

Wegovy is licensed in the UK for reducing cardiovascular risk in adults with established CVD and BMI ≥27

You should not get any withdrawal symptoms from stopping Mounjaro within the 7 days after stopping it. However, you might notice that you start to get your appetite back a little bit. This may happen particularly if you have switched to a slightly lower dose of Wegovy compared to your dose of Mounjaro, this is usually for safety reasons.

When you start Wegovy, you might notice some temporary common side effects, especially after dose increases. Even if you didn't experience side effects on Mounjaro, there is a chance you could experience side effects on Wegovy. These usually go away as your body adjusts to the medication, you are no less or more likely to get side effects from switching medications alone. The 7 day break between Mounjaro and Wegovy is what makes it safe to switch from one to the other.

Common side effects include:

• nausea or vomiting (feeling or being sick)
• diarrhoea or constipation
• stomach pain
• headache
• tiredness

To help manage Wegovy side effects we recommend:

• eating smaller, lighter meals
• avoiding greasy or spicy food
• staying well hydrated
• resting if you feel tired
• eating enough fibre to pass stools
• using over-the-counter medications, like painkillers, for headaches

Most side effects improve as your body gets used to the medication. If they’re severe or persistent, speak to your doctor.

If you do not want to take Wegovy as an alternative, or it’s not suitable for you, there are other weight loss medication options available.

Injections

Nevolat (generic liraglutide) is another GLP-1 medication that works exactly like Wegovy, but is taken once a day. Though, if you cannot take Wegovy, liraglutide is probably not suitable either.

Tablets

Orlistat is a generic weight loss tablet that works differently from weight loss injections. Orlistat is a lipase inhibitor, meaning it blocks the action of the enzyme lipase from breaking down a third of the fat you eat at each meal. You take orlistat with low-fat meals, and the fat that is not broken down will be removed in your stool instead. This helps with weight loss as less dietary fat is absorbed. Orlistat is also available as Xenical (a branded version that costs more), and alli, an over-the-counter version with half dose of the active ingredient.

Mysimba is the other weight loss tablet available in the UK, and you can only get it with a private prescription. Mysimba is similar to weight loss injections in that it can also reduce your appetite, but instead it works on the parts of your brain responsible for hunger and cravings rather than GLP-1 hormones. Mysimba contains the active ingredients naltrexone and bupropion.

Is it safe to switch without a break between Mounjaro and Wegovy?

No, it’s not safe to switch without a break between Mounjaro and Wegovy because there is a risk of serious side effects. Be sure to wait at least 7 days between these medications.

Will switching affect my weight loss progress?

It may not. As you switch, you may find your appetite increases slightly as you may be moving onto a relatively lower dose of Wegovy. Until you move up in Wegovy doses, you may find your progress slows down temporarily.

You may also continue losing weight, especially if you can keep up with your healthy diet and exercise changes. While Mounjaro and Wegovy help with weight loss, they do not cause it – it’s the changes you make to your lifestyle that cause weight loss, the injections just make it easier to stick to these changes.

Are side effects worse when switching from Mounjaro to Wegovy?

No, switching does not make side effects any more or less likely or severe, as long as you wait 7 days between doses.

How long does it take to adjust to Wegovy after switching?

It depends. Everyone reacts differently, and you may adjust straight away because your body was used to Mounjaro, which works similarly, or you may take some time.

Can I switch back to Mounjaro if Wegovy does not work for me?

Yes, but be aware that like with switching from Mounjaro to Wegovy, you’ll need to switch to a slightly lower dose of Mounjaro for safety reasons. These medications are not interchangeable, and we do not recommend switching back and forth often, as it could slow your progress.

Does switching weight loss injections mean I have to start from scratch?

No. With our switching service, swapping from Mounjaro to Wegovy is safe and simple. If your doctor approves your request to switch, meaning that Wegovy is safe for you to use, you can start your first dose of Wegovy just 7 days after finishing your last dose of Mounjaro.