There are many reasons why you might want to switch from Mounjaro to Wegovy. It could be because one isn’t working well for you, or because you’re looking for a cheaper treatment. Either way, it’s possible to switch between weight loss injections if your clinician thinks it’s safe and suitable for you.
In this article, we’ll cover what to expect when switching from Mounjaro to Wegovy so you can continue your weight loss journey safely with the treatment that's best for you.
Three key takeaways
The gap you leave between treatments will be advised by your clinician. This would be at least seven days between your final Mounjaro dose and your first Wegovy dose.
Your new starting dose will be adjusted to help reduce side effects while still supporting weight loss.
Yes, it's possible to switch from Mounjaro to Wegovy, but not right away.
Most people find that a seven-day gap between their final dose of Mounjaro and their first dose of Wegovy is enough to reduce the risk of overlapping side effects, like bloating and nausea.
Plus, there’s no conflict between how Mounjaro and Wegovy work in the body, so there’s very little chance of them interacting with each other.
However, it’s important to note that the manufacturer does recommend leaving 30 days (one month) from your last dose of Mounjaro and your first dose of Wegovy to further reduce the risk of side effects.
If you’ve never taken a weight loss injection before, Wegovy has the same eligibility criteria as Mounjaro. This means you're likely to be approved for Wegovy if you have:
Possibly. If you’ve already lost weight while taking Mounjaro and are now below the eligibility criteria, you may still be able to switch, as long as a clinician approves it.
There are a range of reasons why you might want to switch from Mounjaro to Wegovy, from cost to a lack of cold-chain delivery.
It's cheaper
One of the main reasons you might consider switching from Mounjaro to Wegovy is the cost.
Since the price increases in August 2025, there’s a notable difference between the two. For instance, the starting dose of Wegovy costs £99 at Chemist4U, compared to £148 for Mounjaro.
"This is because there's currently no evidence that semaglutide, the active ingredient in Wegovy, reduces how well the pill works. This is different to Mounjaro, which works slightly differently from other GLP-1 agonists.
“If you're taking Mounjaro alongside the pill, you'll need to use a barrier method, like condoms, for four weeks after starting and for four weeks after any dose increase, or think about switching to a non-oral method of contraception instead."
Unlike Mounjaro, Wegovy doesn't need cold-chain delivery, so it can be shipped to you in regular packaging rather than with ice packs. For some people, this takes the stress out of receiving their order, since there's no need to worry about it staying cold in transit.
The only exception is the highest dose of Wegovy, 7.2mg, as it comes in four separate pens rather than one pen for the month, and still requires cold-chain delivery.
It may work better for you
"Your body is unique, and it can respond differently to various treatments. While Mounjaro and Wegovy work in similar ways, some people tolerate one better than the other, whether that's fewer side effects or better weight loss.
"If you haven't seen the results you were hoping for on Mounjaro, or you're finding the side effects hard to manage, switching to Wegovy could help you find what works best for you."
Ian Budd, Prescribing Pharmacist at Chemist4U
Mounjaro vs Wegovy at a glance
While Mounjaro and Wegovy are similar in many ways, there are some differences, too. Below, we've outlined a comparison between the two to help you decide if switching is the right choice.
Your starting dose of Wegovy depends on which dose of Mounjaro you were taking. But your prescriber will always take your health and how you got on with Mounjaro into account before confirming your dose.
Here's how it breaks down:
Current Mounjaro dose
Starting Wegovy dose
2.5mg
0.5mg
5mg
0.5mg
7.5mg
0.5mg
10mg
1mg
12.5mg
1mg
15mg
1mg
Why does Mounjaro have a higher dose than Wegovy?
Although they work in similar ways, Mounjaro and Wegovy contain different active ingredients, so their doses aren't directly equivalent, and different amounts are needed to achieve similar effects.
How to switch from Mounjaro to Wegovy
Since Mounjaro and Wegovy work in similar ways, with similar ingredients and half-lives, switching between them is considered safe and effective, as long as it's done under the supervision of a medical professional.
Here's how it works:
Request Wegovy by completing an online consultation.
Our clinical team will assess if you can safely switch.
If you're eligible, we'll issue your Wegovy prescription.
Stop taking Mounjaro, then start taking Wegovy after the gap advised by your clinician. This would be at least seven days.
We'll deliver your prescription in discreet packaging.
Start using your new medication and carry on with your weight loss journey.
What to expect when switching from Mounjaro to Wegovy
You might notice mild side effects. Since Mounjaro and Wegovy work in similar ways, most people move across smoothly. That said, some experience slight nausea or an upset stomach for a week or two as their bodies adjust.
Your weight loss shouldn't stall. Mounjaro's effects carry on for a few days after your last dose, so it's unlikely you'll gain weight during the switch. You'll start Wegovy shortly after, keeping your weight loss journey on track.
They're different treatments, not a straight swap. Mounjaro and Wegovy have different active ingredients, so it's best not to think of Wegovy as a direct replacement. Your results and how you respond might feel a little different, and that's completely normal.
Your body might need a bit of time to readjust. Even though both treatments work in similar ways, your body still needs time to get used to something new. Starting on a lower dose helps you ease in gently and keeps side effects to a minimum.
Your pace of weight loss may shift slightly. Everyone responds differently, so you might lose weight faster or slower on Wegovy than you did on Mounjaro. Sticking to a healthy diet and exercise routine alongside your treatment will help you get the best results.
5 tips for safely switching from Mounjaro to Wegovy
Don't rush switching. Leave at least seven days between your last Mounjaro dose and your first Wegovy dose.
Start on the right dose. Begin on the Wegovy dose your prescriber recommends, even if you were on a higher dose of Mounjaro.
Watch out for side effects. Mild nausea or an upset stomach for a week or two is normal, but flag anything that feels off to your prescriber.
Keep your routine. Stick with your healthy eating and exercise habits to help maintain your progress during the switch.
Stay in touch with your prescriber. They're there to help you adjust safely if anything doesn't feel right.
How Chemist4U can help with your switch
Switching treatments can feel like a big step, but our clinical team is with you every step of the way, from your online consultation through to your first Wegovy delivery.
We'll help you find the right starting dose based on your Mounjaro dose, and we're always on hand if you've got questions along the way.
If Wegovy doesn't feel like the right fit, there are other options you can explore, too, like:
Wegovy pill: A once-daily tablet containing semaglutide, the same active ingredient as the Wegovy injection.
Foundayo: A once-daily tablet containing orforglipron, with no food or water restrictions.
Saxenda: A daily weight loss injection containing liraglutide.
Mysimba: A tablet you gradually build up to taking four times a day. Targets the brain's hunger and reward centres to reduce your appetite.
Orlistat (Alli, Orlos, Xenical): Over-the-counter and prescription-only options available. It works by blocking some of the fat in your food from being absorbed. Take one tablet three times daily.
Frequently asked questions about switching from Mounjaro to Wegovy
Can I switch back to Mounjaro after switching to Wegovy?
Yes, you can switch back to Mounjaro, but our prescribers will advise you on how to do this based on your previous treatment use. For more information on switching, read our in-depth guide on switching from Wegovy to Mounjaro.
Is it safe to switch from Mounjaro to Wegovy?
It’s safe to switch from Mounjaro to Wegovy as long as you’re following your prescriber’s advice on how to do so. This means leaving at least seven days between your final Mounjaro dose and first Wegovy dose, and ensuring Wegovy is safe and suitable for you to take.
What is more effective, Mounjaro or Wegovy?
Mounjaro is slightly more effective than Wegovy at its highest dose. On average, people lose 22.5% of their body weight on Mounjaro 15mg, compared to 21% on Wegovy 7.2mg.
Will I experience withdrawal when I stop taking Mounjaro?
There are no withdrawal symptoms when you stop Mounjaro, at least not in the usual sense. Some people notice their appetite increasing as the medicine wears off, but this is completely normal. It's why building healthy habits alongside your treatment is so important to prevent weight regain.
If you feel unwell or are unsure what to expect, speak to our pharmacists.
If I switch to Wegovy, do I need to start from the lowest dose?
If you’re switching to Wegovy from a higher dose of Mounjaro, it’s unlikely that you’ll need to start from the lowest dose. Your starting dose of Wegovy will depend on what dose of Mounjaro you were on, and what your prescriber thinks is safe and suitable for you.
Will I gain weight while switching from Mounjaro to Wegovy?
You may experience an increased appetite initially when you switch to Wegovy. However, as you gradually increase your Wegovy dose, the appetite suppression will become more significant.
Do I need to change my diet after switching?
No, most people won’t need to make any changes, especially if they’re already following a healthy diet. As with Mounjaro, it’s best to stick to a well-balanced diet and limit high-fat foods, alcohol, and caffeine, as these can trigger or worsen symptoms like nausea and indigestion.
If you’re already eating well on Mounjaro, there should be nothing to worry about.
Can you switch from weight loss injections to pills?
Yes, you can switch from injections to pills. Whether you're on Wegovy injections or Mounjaro, it's possible to switch to the Wegovy pill.
In most cases, you'd take your last injection as usual, wait seven days, then start the pill, which you'd take once per day.
Your prescriber will work out the right starting dose for you based on your current dose and how you've been getting on with your medication. Don't stop your injections or start the Wegovy pill without speaking to your prescriber first.
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