Switching from Mounjaro to Wegovy: What to Expect and How to Do It Safely

Medically reviewed by Puja Vyas.

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The reasons why you are looking for answers here could be that your supply got disrupted, the cost has gone up, your provider has changed, or maybe your clinician has a clinical reason to recommend Wegovy instead. Whatever the reason, we are glad you’re not making an uninformed switch.

Firstly, is it okay to switch from Mounjaro to Wegovy? Yes. Switching from Mounjaro to Wegovy is absolutely possible, and it’s more common than you might think. But it’s not as simple as swapping one pen for another.

These are two different medications that work in different ways, and switching safely means understanding what changes, what stays, and what your body may go through during the transition.

We’ve got you covered for all the answers!

Key Takeaways

• Switching from Mounjaro to Wegovy is possible and safe when done under clinical guidance
• A one-week gap between your last Mounjaro dose and first Wegovy dose is usually enough
• Your prescriber may start your Wegovy dose at a lower level as compared to your latest Mounjaro dose
• There may be a short adjustment period, but your weight loss journey should typically resume after that
• Wegovy 7.2mg, the highest semaglutide dose now available, has now been approved in the UK since January 2026 
• Wegovy is now also licensed to reduce the risk of heart attacks and strokes in eligible patients
• At SheMed, we manage every switch with a full blood test and clinician-led dose review from day one

Why Patients Switch from Mounjaro to Wegovy

We’ve already mentioned some of the reasons in the intro paragraph. But just in case you’re curious, here’s an elaborated version of the same -

• Supply and availability - Mounjaro faced some supply constraints in the UK (particularly for the higher-dose pens like 12.5mg and 15mg), which affected many patients in 2025.
• Cost - From September 2025, Eli Lilly increased the list price of Mounjaro significantly across all doses, with 12.5mg and 15mg pens rising to £330 per pack.
• Side effects - Mounjaro’s dual-hormone action may seem more intense for some women, particularly at higher doses.
• Clinical recommendation - Wegovy now has the license to claim reduced risk of heart attacks and strokes in people with established cardiovascular disease. For women with relevant cardiac history, Wegovy becomes a medically preferred choice.
• Provider change – In case of switching providers, the new one may prescribe Wegovy as part of their clinical pathway.

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Should I Switch from Mounjaro to Wegovy?

Let’s start with ‘can’ first, and then we will provide you with all the information you need, so that by the end of the article, you will be able to answer this question yourself.

Can You Swap from Mounjaro to Wegovy?

Yes, you can. But ‘swapping’ isn’t the right word here. It’s not like changing toothbrushes. We are talking about two completely different mechanisms that will work very differently on your body. Hence, switching should only be done under proper clinical guidance.

Here’s why -

How Mounjaro and Wegovy Work Differently in the Body

Both are weekly injections. Both help with weight loss by reducing appetite and slowing the rate at which your stomach empties. But they do this through different hormonal pathways -

• Wegovy contains semaglutide, which acts only on the GLP-1 hormone to slow down stomach emptying and trigger the brain's fullness signals.
• Mounjaro contains tirzepatide, which triggers GLP-1 but also adds a second hormone called GIP. This second hormone improves how your body processes sugar and works as a team with GLP-1, creating a more powerful combined effect on weight loss and appetite control than Wegovy can achieve alone.

Think of it this way: Wegovy turns down the volume on your hunger. Mounjaro turns down the volume and also adjusts the bass. When you switch from Mounjaro to Wegovy, you’re removing the GIP effect. So your appetite control may feel slightly different in the first few weeks as your body recalibrates. That’s completely normal, and usually settles.

Hence, switching requires a proper clinical handover: a review of your history, a decision on starting dose, and a plan for titration.

The most important thing to know here is: Wegovy is a highly effective medication in its own right. It’s not a lesser option.

Will you be starting from scratch if you switch from Mounjaro to Wegovy?

Absolutely not. If you’ve been on Mounjaro and tolerate it well, your body already has an established relationship with GLP-1 receptor activity, one of the two hormone pathways Mounjaro uses, and the same pathway Wegovy uses. That means the transition should be smoother than starting a GLP-1 medication for the first time.

When is switching from Mounjaro to Wegovy not recommended?

Only when it is done impulsively, without clinical input, or because some random reel said that one medication is universally ‘better’ than the other. Both are effective. It’s always about what is right for you, your body and your circumstances.

Is Wegovy as Effective as Mounjaro for Weight Loss?

On paper, Mounjaro has shown slightly higher average weight loss results.

• Mounjaro 15mg produced an average weight loss of 22.5% of body weight over 72 weeks (SURMOUNT-1 trial)
• Wegovy 2.4mg produced an average weight loss of 20.7% over 72 weeks (STEP UP trial)

But the game has changed since Jan, 2026.

•  Wegovy 7.2mg, the newly approved higher dose, produced an average of 20.7% weight loss in the same trial, with 33.2% of participants achieving 25% or more weight loss, a result previously only associated with bariatric surgery or Mounjaro 15mg

This means that the gap between the two medications in terms of results has narrowed considerably with the introduction of Wegovy 7.2mg. For women switching from Mounjaro, the goal of reaching and maintaining 7.2mg Wegovy over time brings efficacy outcomes into a very similar range.

Wegovy 7.2mg: What You Need to Know. 

The MHRA approved Wegovy 7.2mg in the UK on 12 January 2026. It’s intended for people who have already reached and tolerated the 2.4mg dose and need additional support. Currently, it’s administered as three 2.4mg injections in one sitting; a dedicated single-dose pen is expected later in 2026. 

How to Switch from Mounjaro to Wegovy: Step by Step

The process is simple. First of all, you don’t need to decide for yourself. All you need to do is seek guidance and continue your ongoing treatment till then.

Contact Your Current Provider

Let your current provider know you’re considering a switch. They may facilitate it themselves, or they may confirm your details so you can move to a new provider. Either way, don’t just stop taking Mounjaro without a plan. You don’t want an unmanaged gap in your treatment.

If you’re switching to SheMed, you don’t need a referral. We’ll do a clinical assessment and blood test before anything is prescribed.

Keep your documents ready

When you start with a new provider, having your treatment history to hand makes everything easier and safer. Try to have:

• Your current Mounjaro dose and how long you’ve been on it
• The date of your last injection
• Any side effects you’ve experienced, even if you don’t experience them anymore
• Your most recent weight and any blood test results if available
• List of any other medications you take
• BMI before GLP1 treatment was initiated.

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You don’t need a formal letter from your previous provider however we do ask for evidence of your previous prescription of Mounjaro/Wegovy within the last 2 months. 

You can provide either of the following:

• A photo of your medication box with the label clearly visible, showing:
• Your full name
• Prescribed GLP-1 medication and dose
• Date of prescription
• Pharmacy that issued the prescription

OR

• A copy of your current prescription containing the same details.

Once received, we’ll be able to process your switch.

What Happens to Your Prescription

Mounjaro and Wegovy are separate prescriptions. You cannot use a Mounjaro prescription to obtain Wegovy, or vice versa. Once you register with your new provider and complete the clinical assessment, they will issue a new Wegovy prescription independently.

You’re basically just going to start a fresh new treatment.

Do You Need to Restart Your Dosage When Switching?

Not a restart, but you will start Wegovy at a lower dose than you were taking with Mounjaro. You may think of it as a step back, but it’s not. Let us explain - 

What Dose of Wegovy Will You Start On?

There is no officially published dose conversion chart between Mounjaro and Wegovy. This is because the two medications work differently and can’t be directly compared by milligram number.

What prescribers do instead is use clinical judgement, based on your history, tolerance, and the dose ranges of each medication.

So,

• If you were on lower Mounjaro doses (2.5mg–5mg), you’ll typically start Wegovy at 0.25mg–0.5mg
• If you were on mid-range doses (7.5mg–10mg), a starting point of 0.5mg–1mg is more common
• If you were on higher doses (12.5mg–15mg), your prescriber may consider starting at 1mg, though this is always an individual clinical decision

As we said earlier, this isn’t a step backwards. It’s how your prescriber protects you from unnecessary side effects while your body adjusts to Wegovy’s mechanism.

How Long Does the Switch Take?

A one-week gap between your last Mounjaro injection and your first Wegovy injection is generally all that’s needed. Tirzepatide (Mounjaro) has a half-life of approximately five days. This means that by the time you take your first Wegovy dose, your Mounjaro levels will have cleared sufficiently.

The titration period, which is working up to your maintenance Wegovy dose, would take you around 16 to 20 weeks in total.

What to Expect in the First 4 Weeks on Wegovy

The first month is for letting your body adjust to the new mechanism. Here’s what you may experience -

• Appetite changes - Wegovy works on GLP-1 only, as compared to Mounjaro, which works on GIP as well. Naturally, appetite suppression may feel less strong initially.
• The ‘reset’ feeling – Since you’ll be starting Wegovy on a lower dose irrespective of your latest Mounjaro dose, the feeling may be the same as when you started taking Mounjaro.
• Nausea – Some women experience a brief return of nausea initially. Even if you do, it usually goes away in a week or two.
• Weight loss usually continues – If your switch is managed well, your weight loss journey won’t stop. The pace may change initially, but it will catch up soon.

The three most important things to remember here are –

1.    Take your weekly injection on the same day

2.    Stay in contact with your clinical team,

3.     and flag anything that feels unusual

Managing Side Effects After Moving from Mounjaro to Wegovy

You’ve been on Mounjaro, so you’re already familiar with the side effects. It’s going to be similar with Wegovy - nausea, constipation, diarrhoea, and sometimes vomiting, particularly in the early weeks or after a dose increase.

However, a few things are worth knowing when switching -

• Side effects of Wegovy may feel different to what you experienced on Mounjaro - While the list of culprits is the same, different people have different tolerance levels. And some women actually find Wegovy more manageable.
• Starting at a lower dose reduces risk -This is one of the main reasons you don’t start where you left off on Mounjaro. You need to give your body time to adjust to the new mechanism.
• Practical tips - Eat smaller portions, avoid fatty or greasy foods particularly around injection day, stay well hydrated, and don’t lie down immediately after eating.
• Worst case - If side effects get severe, you must inform your prescriber immediately. You can also report side effects to the MHRA via the Yellow Card scheme.

Can You Switch Back from Wegovy to Mounjaro?

Yes, you can, but we would recommend that you let your prescriber make that choice for you.

If you do get a green signal, the same principles apply in reverse: a one-week gap, lower starting Mounjaro dose, and then titrating up based on your response.

Switching from Mounjaro to Wegovy at SheMed

At SheMed, we provide more than just a prescription. If you’re switching from Mounjaro, here’s what your experience with us would look like:

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• Blood test before we prescribe anything - Every new SheMed member gets an at-home blood test as part of onboarding. It helps our clinicians understand your thyroid function, liver enzymes, HbA1c, and cholesterol. This gives them a full metabolic picture and directly informs your Mounjaro starting dose.
• Clinician-led dose decision - Your starting Mounjaro dose is decided by our clinical team based on your Wegovy history, your blood results, and your individual health picture. While we will ask for your preference, our recommended dose will always be data-backed.
• Side-effect care pack included - We know the difficulties you may experience during the switch. And if and when you do, you won’t be left alone. Our side-effect care pack you received when you first joined, is included to help you navigate it smoothly. Our

clinicians are also available to advise about managing side effects.

• 6 and 12-month repeat blood tests - We monitor your metabolic health throughout the programme, not just your weight. We are like that best friend whom you can almost call ‘mom’. 

As we said, you’re not just getting a prescription. You’re going to be in for a personalized treatment plan planned by someone who genuinely cares for you.

And this is why we are trusted by 100,000+ members. 

You can be a part of our family for only £59!

See the Switch & Save offer →

Quick Summary: Just in case you missed something

• You can switch safely as long as the decision is backed by clinicians
• A one-week gap between your last Mounjaro dose and first Wegovy dose is generally all that’s needed
• You’ll start Wegovy at a lower dose than your Mounjaro dose. This is to ensure a smooth transition for your body
• Your body may take 4-6 weeks to adjust to the new mechanism.
• Wegovy 7.2mg has now been approved in the UK since January 2026, and has brought efficacy outcomes closer to Mounjaro’s
• Wegovy is the first GLP-1 medication approved in the UK to also reduce heart attack and stroke risk

And lastly, a good provider will run blood tests, review your history, and manage your overall health, not just issue a prescription.

Frequently Asked Questions

Can I switch from Mounjaro to Wegovy?

Yes. Switching is possible and relatively common in the UK. It should always be done under medical supervision, with a proper clinical assessment and a decided starting dose.

How long do I need to wait between my last Mounjaro and first Wegovy dose?

A one-week gap is generally sufficient. Tirzepatide (Mounjaro) has a half-life of approximately five days, so by the time you take your first Wegovy injection, Mounjaro will have cleared from your system adequately. Your prescriber will confirm the exact timing.

Will I lose my weight loss progress when I switch?

Not if the switch is managed well. Most women continue to lose weight through a well-managed transition. There may be a short adjustment period in the first few weeks, but progress typically resumes as the Wegovy dose increases.

Why does Wegovy start at such a low dose compared to Mounjaro?

The dose ranges for Mounjaro and Wegovy are completely different. They measure different strengths in different units. Hence, the numbers can’t be directly compared. Starting at a lower Wegovy dose lets your body adjust to the different mechanism and reduces the risk of side effects.

Is Wegovy as good as Mounjaro for weight loss?

Both are highly effective. In clinical trials, Mounjaro 15mg showed slightly higher average weight loss (22.5% vs 20.7% at 72 weeks for Wegovy 2.4mg). However, Wegovy 7.2mg, now approved in the UK since January 2026, has produced results comparable to Mounjaro’s highest dose, with 33.2% of participants achieving 25%+ weight loss.

What is Wegovy 7.2mg and does it affect my switch?

Wegovy 7.2mg is the newest and highest dose of semaglutide, approved by the MHRA in January 2026. It’s a step-up option for people already on 2.4mg who need further support.

Can I switch back to Mounjaro if Wegovy doesn’t work for me?

Yes, with clinical support. Switching in either direction is possible. If you switch back to Mounjaro from Wegovy, you’ll still need to start at a lower dose (typically 2.5mg or 5mg) regardless of your previous Mounjaro history, because Mounjaro’s GIP mechanism will be new to your body again.

Sources & Further Reading

1. MHRA — GLP-1 Medicines for Weight Loss and Diabetes: What You Need to Know (GOV.UK, updated 2026)

2. NHS England — Over a million people could be offered Wegovy to cut heart attack and stroke risk (April 2026)

3. NICE — Tirzepatide (Mounjaro) for Managing Overweight and Obesity (TA1026)

4. SURMOUNT-1 Trial — Tirzepatide Once Weekly for the Treatment of Obesity (NEJM, 2022)

5. STEP UP Trial — Once-Weekly Semaglutide 7.2mg in Adults with Obesity (Lancet Diabetes & Endocrinology, 2025)

6. NHS — Obesity Treatment Overview

7. SheMed — Switch to SheMed: Blood-Test-Included GLP-1 Programme