Switching From Mounjaro To Wegovy: Is It Possible?

Changing from one weight loss medication to another can feel daunting, especially if you’re unsure whether it’s possible or how to do it safely. If you are currently taking Mounjaro and wondering if Wegovy might be a better fit, this article will help. We’ll explain the key differences between Mounjaro and Wegovy, why some people consider switching, who is eligible and how to switch safely under medical supervision.

Key Takeaways

Here are the five biggest takeaways from this article about switching from Mounjaro to Wegovy:

• Mounjaro contains tirzepatide, while Wegovy contains semaglutide. Both are effective for weight loss but act slightly differently in the body.

• To switch, you must meet the eligibility criteria for Wegovy, usually a BMI of 30 or more (or 27–30 with a weight-related condition).

• You will normally need a wash-out period of at least four to five weeks to allow Mounjaro to leave your system before starting Wegovy.

• Wegovy is started at the lowest dose and gradually increased to help reduce side effects such as nausea, diarrhoea or constipation.

• Switching should always be done with the support of a healthcare professional to keep the process safe and effective.

What are the differences between Mounjaro and Wegovy?

Mounjaro and Wegovy are both prescription-only treatments for weight loss, but they are not the same.

• Mounjaro (tirzepatide): Targets two different receptors (GIP and GLP-1), which can help regulate blood sugar and appetite. It is licensed in the UK for type 2 diabetes, but also used for weight management.

• Wegovy (semaglutide): Targets GLP-1 receptors only, helping to reduce appetite and slow digestion. It is specifically licensed for weight loss in the UK.

Both follow titration dosing schedules, starting at a low dose and gradually increasing to reduce side effects such as nausea, vomiting, constipation or diarrhoea.

• Learn more about the titration dosing schedule for Wegovy

• Learn more about the titration dosing schedule for Mounjaro

Why would I consider switching from Mounjaro to Wegovy?

There are several reasons you may think about changing from Mounjaro to Wegovy:

Different effectiveness

Some people respond better to semaglutide (Wegovy) than tirzepatide (Mounjaro), even though clinical trials suggest tirzepatide may produce more weight loss for some.

Side effect tolerance

Everyone’s body reacts differently. If you’ve experienced unwanted side effects with Mounjaro, Wegovy may be more suitable.

Personal preference

Some patients simply wish to try an alternative after not seeing the results they expected on Mounjaro.

Price changes

It was recently announced that Eli Lilly, the company that supplies Mounjaro, would be increasing the price of Mounjaro to suppliers [1]. This subsequently increases Mounjaro prices for customers. This makes Wegovy an attractive alternative due to its lower price.

Whatever your reason, a doctor or independent prescriber can help you decide if switching is appropriate.

Am I eligible to switch from Mounjaro to Wegovy?

You may be eligible if you meet the standard prescribing requirements for Wegovy. This usually means:

• BMI 30 or higher, or between 27 and 30 with a weight-related condition such as high blood pressure or prediabetes.

• Being over 18.

• Not being pregnant or breastfeeding.

• Not taking medicines that interact with semaglutide.

A healthcare professional will need to review your medical history, allergies and current treatment before confirming whether Wegovy is suitable for you.

How to switch from Mounjaro to Wegovy

Switching from Mounjaro to Wegovy should be carefully planned. The process usually involves:

1. Stopping Mounjaro

Consult with a healthcare provider to get advice on when and how to stop taking Mounjaro. Some people may be able to stop directly, while others may stop more gradually depending on their dose and tolerance.

2. Wash-out period

You’ll typically need to wait around seven days before starting Wegovy. This allows tirzepatide to clear from your system and helps avoid overlapping effects or side effects. During this break, you may notice your appetite returning to pre-treatment levels, but this is not the same as withdrawal.

3. Starting Wegovy

Once the wash-out is complete, you will usually start on the lowest dose. Like Mounjaro, Wegovy dosing increases gradually over time until you reach a maintenance level. This helps your body adjust and reduces the chance of side effects [2]. The strength of Mounjaro you were using may influence the dose of Wegovy you start on. You may be told to use the doses below:

• 2.5mg Mounjaro = 0.25mg Wegovy

• 5mg Mounjaro = 0.5mg Wegovy

• 7.5mg Mounjaro = 1mg Wegovy

• 10-15mg Mounjaro = 1.7mg Wegovy

It is important to consult with a healthcare professional if you are thinking about switching from Mounjaro to Wegovy.

FAQs about switching from Mounjaro to Wegovy

Can I use Mounjaro and Wegovy at the same time?

No. The two should not be used together. Combining them would increase the risk of side effects and is unsafe.

Can I switch directly from Mounjaro to Wegovy without waiting?

No. A wash-out period of at least four to five weeks is recommended. This ensures tirzepatide has left your system before starting semaglutide.

Will I get withdrawal symptoms?

No. Stopping Mounjaro does not usually cause withdrawal. However, you may notice your appetite increasing during the waiting period.

Is Wegovy less effective than Mounjaro?

Not necessarily. Some people respond better to semaglutide, while others do better with tirzepatide. Effectiveness varies from person to person.

Final Thoughts

Switching from Mounjaro to Wegovy is possible, but it must be done with medical guidance. Both are effective weight loss treatments, but they contain different active ingredients and work in slightly different ways. A safe transition usually involves stopping Mounjaro, waiting four to five weeks, and then starting Wegovy at a low dose.

If you are considering switching, always consult with a healthcare professional. They will ensure the process is safe, check that you meet the eligibility criteria and help you achieve the best outcome for your weight loss journey.

Sources

[1] Mounjaro UK Price Increase (September 2025 Edition) - UK Meds

[2] A Simple Guide To Wegovy Dosing & Titration: When & How To Take The Semaglutide Injection For Weight Loss - UK Meds