Switch from Mounjaro to Wegovy

Mounjaro and Wegovy are both injectable weight loss medications that work in a very similar way, as they both contain a glucagon-like peptide-1 (GLP-1) receptor agonist. They reduce your appetite and keep your stomach fuller for longer, so it becomes easier to reduce your calorie intake and follow healthy lifestyle changes to lose weight.

There are many reasons people switch between medications, such as if one is significantly cheaper than the other, which is now the case for Mounjaro and Wegovy. Switching from Mounjaro to Wegovy is relatively easy. If you’re already eligible for Mounjaro, you’re likely to be eligible for Wegovy too.

Here, we look at how you can switch from Mounjaro to Wegovy, how long it takes, and answer any other questions you may have about the process.

Yes, after you’ve had Wegovy treatment approved for you by a doctor, you can stop Mounjaro after your last dose. Then, you’ll simply need to wait for 7 days before taking your first Wegovy dose. The process is relatively straightforward.

Most patients can switch from Mounjaro to Wegovy, following a doctor safety review since Wegovy has the same body mass index (BMI) requirements and similar health considerations. 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.

This means you can request to switch:

• even if you've reached a healthy BMI of 25 or lower
• if you're not pregnant or breastfeeding
• as long as have not had severe side effects from Mounjaro, such as pancreatitis or a severe allergic reaction (this may make Wegovy unsuitable for you)
• if you have no allergies to its active ingredients

To switch from Mounjaro to Wegovy:

• submit a treatment request for Wegovy – our doctors will review and approve the switch where safe and appropriate.
• stop taking Mounjaro after your last injection – stop Mounjaro when you’re ready, there’s no need to wean yourself off it.
• wait 7 days before starting Wegovy – you should wait until the day your next Mounjaro dose is due to take your first dose of Wegovy to make sure you’re taking it safely.
• start Wegovy at the new dose your doctor has approved for you, 7 days after your last Mounjaro dose.

➤ Find out more about the Wegovy dosage schedule.

Here’s a guide for the maximum dose of Wegovy you could switch to based on your current Mounjaro dose:

A doctor will confirm the right dose for you to switch to when they approve treatment. This may be lower than the maximum switching dose if you’ve experienced side effects on Mounjaro.

Mounjaro vs Wegovy comparison

There are many reasons why people switch from Mounjaro to Wegovy, some are listed here.

Cost

Eli Lilly, the manufacturer of Mounjaro, has increased its prices as of 1 September 2025. If you can no longer afford Moujaro at its new price, or you’d prefer not to spend that much, Wegovy is now the most affordable option.

➤ See our Mounjaro price change FAQs for more information.

If you are not getting the weight loss results you expect on Mounjaro

Mounjaro has been proven to be slightly more effective in clinical trials, with up to 22.5% weight loss reduction at 72 weeks compared to an average of 21% for Wegovy at 72 weeks, both at the maximum dose. However, people’s individual experiences with medications can differ. Some people may not see the results they are expecting from Mounjaro and could respond better to a different treatment.

Side effects

Mounjaro and Wegovy can both cause side effects, and because they work in a similar way, side effects are quite similar. That being said, just because you get Mounjaro side effects does not necessarily mean you’ll get Wegovy side effects, as it’s still a different medication. If your side effects are not going away, you and your doctor may decide switching is best.

If your side effects are very severe, you must let your doctor know, as it may be that weight loss injections like Mounjaro and Wegovy are not suitable for you.

You can switch from Mounjaro to Wegovy if you still meet the prescribing guidelines for Mounjaro, as Wegovy has the same body mass index (BMI) requirements and considerations.

This means you can switch:

• even if you've reached a healthy BMI of 25 or lower
• if you're not pregnant or breastfeeding
• as long as have not had severe side effects from Mounjaro, such as pancreatitis or a severe allergic reaction (this may make Wegovy unsuitable for you)
• if you have no allergies to its active ingredients

Although you’re likely to be able to take Wegovy if you can take Mounjaro, you should always check with your doctor or request a Wegovy prescription first to make sure.

There are no withdrawal symptoms from stopping Mounjaro, even if you stop it suddenly or on the highest dose. During the 7 days after stopping Mounjaro, you should not notice any changes, since this is how long you would normally wait between doses.

You may notice your appetite increases slightly. This is because you might be switching to a slightly lower dose of Wegovy relative to your Mounjaro one, for safety reasons. This means you may feel slightly less effective from your treatment, at least until you titrate up again.

Common side effects when switching from Mounjaro to Wegovy

Once you start Wegovy, there’s a chance that you’ll get some Wegovy side effects, which are most common when starting treatment and after a dose increase. Very common side effects of Wegovy that may be likely when you first switch include:

• feeling tired or weak
• headaches
• feeling and/or being sick (nausea and vomiting)
• diarrhoea or constipation
• pain in your stomach

You may get side effects on Wegovy even if you did not with Mounjaro, or you may not get any even if you did with Mounjaro. These side effects usually go away as your body adjusts to the medication, and you are no more or less likely to get side effects from switching.

If there’s a reason you can no longer take Mounjaro, such as due to the price increase, switching could be a great alternative to stopping treatment altogether. Although Mounjaro has slightly higher weight loss results, Wegovy is still a very effective weight loss medication that works in almost the same way, so you do not need to let this stop you from reaching your goal weight.

Learn more about Wegovy before switching:

Mounjaro KwikPen 2.5mg solution for injection in pre-filled pen, emc [accessed 15 August 2025]

Wegovy 0.25 mg, FlexTouch solution for injection in pre-filled pen, emc [accessed 13 January 2026]

Cost of weight-loss drug Mounjaro could rise significantly, BBC News [accessed 15 August 2025]

Mounjaro, Eli Lilly [accessed 15 August 2025]

Overweight and obesity management, NICE guidelines [accessed 15 August 2025]