If you’re currently using Mounjaro and are thinking about moving to Wegovy, you’ll be pleased to know that switching is possible, but only if your pharmacist or healthcare provider feels it’s appropriate for you. Because these medications work in similar ways, the changeover needs to be done carefully to ensure it’s both safe and effective.
Typically, there should be a gap of around seven days between your final dose of Mounjaro and your first dose of Wegovy. The dose you start on with Wegovy will also depend on the strength of Mounjaro you were previously prescribed, so your treatment plan may need to be adjusted.
This article will walk you through what to expect when making the switch, the benefits of each option, and the practical steps you’ll need to follow. Our goal is to give you the information you need to make a confident and informed decision about your weight-loss journey. If you ever feel unsure, remember that your pharmacist or clinician is the best person to give tailored advice.
How the treatments work
Both Wegovy and Mounjaro belong to the same family of medicines known as GLP-1 receptor agonists. They support weight loss by helping you feel fuller for longer and slowing down how quickly food leaves your stomach. The main difference is that Mounjaro also works on GIP receptors, which means it can aid in blood sugar control as well as weight management.
A short pause is needed when switching
You shouldn’t move directly from one treatment to the other. Most patients are advised to leave at least a week between their last Mounjaro dose and their first Wegovy injection to ensure the transition is smooth.
Your dose may be different
When starting Wegovy, your pharmacist will adjust the dose according to the strength of Mounjaro you were previously using. This step helps your body adapt and reduces the risk of side effects.
Why patients switch
People choose to move from Mounjaro to Wegovy for different reasons, sometimes because Wegovy can be the more cost-effective option, or because of side effects, or simply a preference for one treatment over the other. Studies have shown that both medicines are safe, reliable, and deliver comparable weight-loss results.
If you’re considering moving from Mounjaro to Wegovy, the process is straightforward but must be done carefully to keep you safe. Here’s how it works:
Begin with an online consultation
Simply complete our short health assessment form. This gives our clinicians the information they need to understand your medical history and current treatment.
Clinical review by our experts
Our healthcare team will carefully check whether changing to Wegovy is suitable for you. Safety always comes first, so they’ll only recommend the switch if it’s appropriate.
Prescription issued if approved
If you’re eligible, a prescription for Wegovy will be written for you.
Pause your Mounjaro treatment
Before starting Wegovy, you’ll need to stop using Mounjaro. This ensures your body has time to reset.
Allow a 7-day gap
A waiting period of at least one week is required between your last Mounjaro dose and your first Wegovy injection. This “washout” time reduces the risk of side effects.
Discreet home delivery
Once prescribed, your medication will be sent directly to your address in plain, secure packaging. Remember, Wegovy must be stored in the fridge as soon as it arrives.
Begin your new treatment
After the waiting period, you can start Wegovy as advised. With the right support, you can continue progressing toward your weight-loss goals.
Wondering if you qualify for Wegovy? The eligibility requirements are very similar to those for Mounjaro, so if you’ve been considering weight-loss injections, chances are you may be suitable.
You could be prescribed Wegovy if you meet one of the following criteria:
If you’ve already started your weight-loss journey with Mounjaro and your BMI has dropped below these thresholds, you may still be able to move across to Wegovy. In these cases, a pharmacist or prescriber can authorise Wegovy as part of your long-term weight-management plan, helping you maintain your progress and continue building healthy habits.
Yes, in some cases. If you’ve already been using Mounjaro and have successfully reduced your weight below the BMI threshold, or you’re now using the medication simply to help maintain your target weight, you may still qualify to switch to Wegovy. Before making that change, our clinical team will carefully review your health background to confirm whether the treatment is both safe and appropriate for you.
You should not stop taking Mounjaro on your own. Always wait until a pharmacist or prescriber has officially approved your switch to Wegovy. Once the change is confirmed, or if you’ve already taken your final Mounjaro injection, simply leave a minimum gap of seven days before beginning Wegovy. There’s nothing further you need to do other than not taking another Mounjaro dose.
Wegovy should be started at least one week after your last Mounjaro injection, at the dose recommended by your prescriber. The medication comes as a once-weekly pre-filled injection pen, which you can administer yourself into the abdomen, thigh, or upper arm. It’s important to use it on the same day each week for consistency. If you’d like more detail, including step-by-step instructions and illustrations, you can refer to our injection guide.
Although Mounjaro and Wegovy are similar, you’ll notice a few small but practical differences when moving from one to the other.
Injection Pens
Wegovy: The pen only needs to be primed before the first use. After that, you can inject directly without priming each time.
Mounjaro: Requires priming before every single injection, which can be slightly less convenient.
Storage Conditions
Both medicines should be kept refrigerated until the pen is first used.
Once in use:
Mounjaro can be stored at room temperature (up to 30°C) for 30 days.
Wegovy lasts longer — it can remain at room temperature for up to 42 days.
For most patients, switching from Mounjaro to Wegovy is considered safe if done correctly. Here’s why:
Similar Mechanism: Both act on GLP-1 receptors, slowing digestion and reducing appetite.
Additional Action with Mounjaro: Mounjaro also targets GIP receptors, but these effects gradually wear off when the treatment is stopped.
Washout Period: A short seven-day break is usually enough to reduce the overlap between treatments and avoid compounding side effects like nausea, bloating, or constipation.
No Interaction Risk: The medicines don’t conflict with one another, and both have a long half-life (they remain in the body for days after injection), which helps make the transition smoother.
Important: Some clinical guidance recommends waiting up to 30 days between treatments to further lower the chance of side effects. However, this may slow down progress in your weight-loss journey. Always follow the advice of your prescriber.
Switching medications is a personal choice, but here are some of the most common reasons:
1. Side Effects and Tolerability
Even though the two drugs are similar, people react differently. Some patients find they tolerate Wegovy better, with fewer issues like diarrhoea, constipation, or vomiting. If Mounjaro side effects are interfering with daily life, Wegovy may feel easier to manage.
2. Progress and Effectiveness
Weight-loss journeys often hit a plateau. While this is normal, if your weight loss stalls for an extended period, it might be due to how your body is responding to treatment. Wegovy could help you break through that plateau.
Recent clinical trials show Wegovy patients losing an average of 20.7% of their body weight, with some individuals losing 25% or more. These results are now approaching the weight loss outcomes typically seen with Mounjaro.
3. Cost Considerations
For many patients, Wegovy is the more affordable option, making long-term treatment more sustainable.
4. Heart Health Benefits
Wegovy is the only weight-loss injection currently licensed to lower the risk of serious cardiovascular events (heart attack, stroke) in patients with obesity and existing heart disease. While early research suggests Mounjaro may provide similar benefits, it is not yet licensed for this purpose.
5. Contraception
Unlike Mounjaro, Wegovy does not interfere with oral contraceptives, meaning you won’t need to make changes to your birth control.
Will I Experience Side Effects When Switching?
Some people notice side effects during the transition, especially if switching after only one week. These may include:
Nausea
Bloating
Constipation
Diarrhoea
Usually, these symptoms are mild and temporary, easing within a couple of weeks.
To make the switch smoother:
Your pharmacist may start you on a lower dose of Wegovy and increase gradually.
Waiting longer than seven days before starting Wegovy can further reduce side effects.
If you tolerated Mounjaro well, you’ll likely adjust to Wegovy without major issues.
Yes, you can switch back, but only if your prescriber feels it’s safe for you. They’ll want to understand your reasons first, just to make sure it’s the best choice for your health
Yes, you can safely switch from Mounjaro to Wegovy but only if you follow your prescriber’s guidance. Usually, this means leaving at least seven days between your last Mounjaro dose and your first Wegovy dose, and making sure Wegovy is the right and safe option for you.
You won’t get “withdrawal” symptoms in the typical sense. What some people do notice is that their appetite comes back once the medicine wears off. Any side effects you’ve had usually fade once you stop taking it. If you’re ever unsure or don’t feel well, our pharmacists are here to help, just reach out.
If you’re moving over to Wegovy after taking a higher dose of Mounjaro, you probably won’t need to begin at the very lowest dose. The dose you start with on Wegovy will depend on the amount of Mounjaro you were previously using, and on what your prescriber feels is safe and right for you.
It’s not very likely that you’ll gain weight when switching. The effects of Mounjaro last for about a week after your final dose, and you’ll start Wegovy straight away, which works in a similar way. This means your treatment keeps going without a break, so you should be able to carry on losing weight especially if you keep up with your eating plan and regular exercise.
Not really. If you’re already eating a healthy, balanced diet, you usually don’t need to make any changes. Just like with Mounjaro, it’s a good idea to keep meals balanced and try to avoid too much fatty food, alcohol, or caffeine, as these can sometimes make side effects like nausea or indigestion worse. If your diet was working well for you on Mounjaro, you should be absolutely fine.
