Switching from Wegovy to Mounjaro: How it Works

If you’re currently taking Wegovy for weight loss, there’s a good chance that you’ve also heard about its closest competitor, Mounjaro. Containing the active ingredient, tirzepatide, Mounjaro has become widely known for delivering impressive before-and-after transformations. 

While both are brilliant medications for supporting weight loss, Mounjaro is always seen as having the edge in terms of potential results, while Wegovy is considered more cost-effective. So, should you stick with what you’re currently taking or move on to something else?

There are many reasons why you may want to change your weight loss medication. Perhaps you’re no longer losing weight with Wegovy, are struggling with side effects, or simply think that Mounjaro would be better suited to your body and lifestyle. 

Whether you’re just deliberating or are determined to make the change, this article outlines everything you need to know about switching from Wegovy to Mounjaro, so you have a clear idea of what to expect. Let’s begin. 

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How Are Wegovy and Mounjaro Different?

While both Wegovy and Mounjaro are weekly weight loss injections, they’re not the same. Wegovy contains semaglutide, which mimics a hormone called Glucagon-Like Peptide-1 (GLP-1) to promote feelings of fullness. Mounjaro, on the other hand, contains tirzepatide and targets both the GLP-1 and Gastric Inhibitory Polypeptide (GIP) hormone pathways, making it a dual agonist.  

In clinical trials, Wegovy has been shown to help people lose an average of 14.9% of their body weight over a 60-week period. Meanwhile, Mounjaro users may experience a 22.5% drop after 72 weeks. 

When placed head-to-head, people using Mounjaro lost approximately 20% of their body weight compared to 14% with Wegovy over 72 weeks. These results explain why Mounjaro is considered the most effective medication for weight loss. 

Can You Switch from Wegovy to Mounjaro?

Yes, it is possible to switch from Wegovy to Mounjaro. You’ll need a new prescription and proper medical supervision to do so safely, since each treatment contains different active ingredients and may affect your body differently. A clinician will therefore need to assess whether Mounjaro is right for your situation and health history before proceeding.  

While the side effects of Wegovy are similar to those of Mounjaro, some individuals may tolerate one medication better than the other. As a result, it’s essential to have a clear understanding of where you stand. It’s ultimately not as simple as just swapping one injection for another.

Another point to consider when thinking about switching from Wegovy to Mounjaro is the starting dosage of the new treatment. Even if you’re currently on the highest dose of Wegovy, you’ll need to begin with Mounjaro at the 2.5 mg starting dose and work your way up gradually. 

Who Can Take Each Medication?

Both Mounjaro and Wegovy have similar eligibility requirements. You’ll typically need to have a body mass index (BMI) of 30 or above (which is classified as obesity) or a BMI of 27-30 with weight-related health conditions, such as diabetes, high blood pressure, or high cholesterol. 

Your medical history matters, too. Each treatment may interact differently with other medications you may be taking, while neither of them is suitable if you’ve had certain types of thyroid cancer or severe stomach problems. All of this needs to be taken into account so any potential switch can be carried out as safely as possible. 

Why Change from Wegovy to Mounjaro?

There are several reasons why you may want to change from Wegovy to Mounjaro. These range from the potential for better weight loss results to each medication having a different side effect profile. Careful consideration of all these points is necessary to make an informed decision about which treatment is best suited for your specific circumstances.

Let’s take a look at the main reasons for changing from Wegovy to Mounjaro in more detail: 

• Weight Loss Potential: Although it’s still possible to achieve great results with Wegovy, several real-world studies have shown that Mounjaro delivers superior weight loss. This can largely be down to the higher maintenance dose and the dual-agonistic properties of tirzepatide. 
• Breaking Through Plateaus: If your weight loss has stalled on Wegovy, switching to Mounjaro's different mechanism might get things moving again. Some people find the switch gives them a fresh start.
• Different Side Effect Profile: While both medications can cause similar side effects (mainly stomach-related), some people find they tolerate one better than the other. If you're struggling with persistent nausea or other issues on Wegovy, Mounjaro might be gentler for you.

Mounjaro

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• Approved Weight Loss Treatment
• Suitable for adults with a BMI of +30kg/m²
• Pre-filled injection pen

• Discreet delivery next working day
• Online prescription - No doctor visit

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How to Switch from Wegovy to Mounjaro

Switching from Wegovy to Mounjaro is a relatively straightforward process; however, it requires some forward planning. You’ll need to start a new consultation, discuss your medical history, and complete a brief transition period before commencing the new treatment. 

Here’s an explanation about how to switch from Wegovy to Mounjaro in a bit more detail:

1. Start a New Consultation: You’ll need to speak with a clinician who can prescribe Mounjaro. This will usually be your current provider of Wegovy. 
2. Provide Relevant Information: It’s essential to review your medical history and discuss your experience with Wegovy, so that the prescriber can determine whether Mounjaro would be suitable for you. They may even ask you about your weight loss goals.
3. Stop Taking Wegovy: If your new Mounjaro prescription is approved, you’ll need to stop using Wegovy once your current pen finishes. Should you be unable to handle Wegovy’s side effects, consult your clinician, and they may advise you to stop treatment immediately. 
4. Wait it Out: You’ll need to wait until Wegovy has left your system before starting Mounjaro treatment.
5. Begin Mounjaro: It’s now time to administer your Mounjaro injections. Remember that you’ll need to start with the lowest dose of tirzepatide and gradually increase it.
6. Be Patient: Although Mounjaro is highly effective for weight loss, results don’t happen immediately. It may take several weeks for you to feel the effects of your new medication. 

Since both Wegovy and Mounjaro follow similar dosing schedules, you should be able to incorporate the new treatment into your existing routine. You may also want to research the foods to eat with Mounjaro and potential exercise routines to help support you in your journey. 

How Long Does Wegovy Take to Leave Your System?

Semaglutide (Wegovy’s active ingredient) has an elimination half-life of approximately 7 days. This is the amount of time it takes for a drug to decrease to half its original amount in the body. As a result, it can take between 5 and 7 weeks for the medication to fully leave your system. 

“It’s important to allow Wegovy to fully leave your system before starting Mounjaro. This is because both medications act on gut hormone pathways known as incretin. Incretins are natural hormones released after eating that help regulate appetite and stimulate insulin release to control blood sugar. The fact that both treatments impact incretins means that taking them too close together could result in overlapping drug effects. This may lead to an increased risk of gastrointestinal side effects and low blood sugar (hypoglycemia). Allowing Wegovy to fully clear before starting Mounjaro reduces the potential of cumulative side effects and also provides a safer baseline to monitor how your body responds to tirzepatide.”

Cong Cao, Pharmacist

Changing from Wegovy to Mounjaro: Dosage Information

Even if you’re currently taking the highest dose of Wegovy (2.4 mg taken once per week), it’s not possible to jump straight to a high dose of Mounjaro. You’ll instead need to start on the lowest strength of tirzepatide. 

Although this may seem frustrating, there is a good reason behind it. Wegovy and Mounjaro contain completely different active ingredients that work through different pathways in your body. It’s therefore essential to start at a very low dosage to give your system the chance to safely adjust to tirzepatide and minimise the risk of side effects. 

Once you’ve started, you should then be able to increase your dosage every four weeks until you reach the maximum maintenance dose of Mounjaro. This may take longer than the usual schedule if your body needs extra time to adapt to the medication, though this will be assessed on a case-by-case basis. 

Here’s how Wegovy’s dosage schedule compares with Mounjaro: 

Wegovy Schedule 

Wegovy’s starting dose is 0.25 mg of semaglutide, administered once weekly. This will usually increase every four weeks until you reach the maximum dose of 2.4 mg. 

Mounjaro Schedule

Mounjaro treatment begins with a 2.5 mg dose of tirzepatide, administered once per week. The strength will typically increase on a monthly basis, up to the maximum maintenance dose of 15 mg. 

What to Expect When Moving from Wegovy to Mounjaro

The transition period can feel a bit unsettled as one medication leaves your system and the other takes over. Initially, you may experience a return of appetite or cravings as the effects of Wegovy wear off and before Mounjaro reaches its full effect. This is completely normal and typically resolves as your Mounjaro dose increases.

Clinical studies have shown that people switching from Wegovy to Mounjaro, or from any other GLP-1 medication, typically experience continued weight loss and improved results with tirzepatide. Some individuals have even reported that Mounjaro provides smoother and more consistent appetite control when compared to Wegovy, though each person’s experience will be different. 

Mounjaro

Rated 0 out of 5 based on 0 reviews

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• Approved Weight Loss Treatment
• Suitable for adults with a BMI of +30kg/m²
• Pre-filled injection pen

• Discreet delivery next working day
• Online prescription - No doctor visit

Prices from £179.99 Review More Prices

Start Order More Info

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Switching from Wegovy to Mounjaro: Frequently Asked Questions

Can You Alternate Between Wegovy and Mounjaro?

No, it’s not recommended to alternate between Wegovy and Mounjaro. This practice could be unsafe due to unpredictable drug interactions and dosing complications. Indeed, switching back and forth would make it impossible to properly titrate either medication to its optimal dose for weight loss. 

Both Mounjaro and Wegovy need consistent use to build up to therapeutic levels and maintain stable effects. As a result, healthcare providers will typically recommend committing to one medication for several months before considering any changes. 

Can You Take Wegovy and Mounjaro at the Same Time?

No, taking Wegovy and Mounjaro at the same time is not recommended. Doing so could significantly increase your risk of severe side effects without providing any additional benefits. Both treatments can cause similar reactions in the body, so combining them will likely amplify things such as nausea, vomiting, and stomach pain.

Due to this, it may be hazardous for you to take both treatments simultaneously. You should instead always stick to one GLP-1 medication at a time. 

Can You Switch from Mounjaro to Wegovy?

Yes, it’s possible to switch from Mounjaro to Wegovy. You would need to start a new consultation, receive a prescription for semaglutide, and begin at the lowest dose of Wegovy. Your healthcare provider will also assess your reasons for wanting to change to ensure total safety. 

Some individuals may find that they need to switch back from Mounjaro to Wegovy if their initial switch didn’t go as planned. This is completely normal and will be facilitated by a clinician. It’s essential not to switch back and forth too frequently, as this can have a detrimental effect on your weight loss progress.

Will I Get Withdrawal Symptoms When Switching from Wegovy to Mounjaro?

No, you won’t get withdrawal symptoms when switching from Wegovy to Mounjaro. However, you may notice a gradual return of appetite and cravings as semaglutide clears from your system. The impact of this is generally mild and should improve once you’ve started tirzepatide and the new drug has reached therapeutic levels in your body. 

During this transitional period, it’s crucial that you maintain the healthy routine you started with Wegovy. Be sure to stick to a calorie-controlled diet and engage in regular exercise to minimise the risk of a plateau or weight gain.

Make The Switch From Wegovy to Mounjaro

Switching from Wegovy to Mounjaro can be an excellent strategy for enhancing your weight loss journey, whether you're looking for better results, improved tolerability, or simply want to try the most advanced treatment available. The key is doing it properly with medical supervision and realistic expectations about the process involved.

At Prescription Doctor, we understand that your weight loss journey is personal and important. That's why we offer comprehensive consultations with experienced, GPhC-registered pharmacists who can help determine the best medication for your individual circumstances. 

We've been supporting people with their weight management goals since 2013, and make the process as smooth as possible with discreet packaging and next-day delivery when orders are approved before 3 pm on weekdays. 

We also offer ongoing guidance to help you get the best results from whichever treatment you choose. Our clinicians will regularly check in with you to monitor your progress and ensure everything is working correctly. They are also available to answer any questions you may have about your medication. 

Ready to explore whether Mounjaro might be right for you? Start your consultation with Prescription Doctor today and let us help you take the next step toward achieving your weight loss goals.

Authored By

Sam Jeans

Medical Content Writer

Sam has been a freelance writer since 2015, with extensive experience in the medical, scientific, and technology fields. He holds an MSc in International Development and Social Anthropology, bringing

Published on: 29/09/2025

Reviewed By

Mohamed Imran Lakhi

MPharm - Lead Pharmacist

Imran Lakhi is the superintendent pharmacist and founder at Prescription Doctor. He has been at the core of our team.

Reviewed on: 29/09/2025