Mounjaro vs Wegovy: What’s the Difference and Which One’s Right For You?
Mounjaro vs Wegovy: What’s the Difference and Which One’s Right For You?
When you're weighing up weight loss treatments, it helps to know exactly what you're choosing between.
You've now got three main options: the Wegovy injection, the newer Wegovy pill, and Mounjaro. All have been proven safe and effective for weight loss, though there are some differences to be aware of, like price, active ingredient, and the doses on offer.
Here's everything you need to know about all three, so you can work out which one fits your weight loss journey best.
Three key takeaways
Mounjaro and Wegovy both work in a similar way. Whichever form you take, the active ingredient sends signals to your brain to help you feel fuller after eating, in addition to slowing how quickly food leaves your stomach, so that feeling of fullness lasts longer.
Since they’re all the same type of medication, all three share similar common side effects.
Is Mounjaro or Wegovy better for weight loss?
Mounjaro is considered slightly more effective on average, but all three treatments have helped people safely and successfully reach their weight loss goals.
In clinical trials, Mounjaro helped people lose an average of 22.5% of their body weight over 72 weeks.
The Wegovy pill has also been shown to be very effective. During the initial OASIS 4 clinical trial, patients on average lost around 17% of their starting weight, though in a later analysis, early responders (people who'd lost more than 10% of their starting weight by week 16) went on to lose 22% on average by the end of 64 weeks.
This means that all three treatments are effective for weight loss, but Mounjaro may lead to slightly greater results for some people. That said, everyone reacts to treatments differently, so there's no single best or most effective option for everyone. It's about finding what works best for you.
Whether you're taking Mounjaro, the Wegovy injection, or the Wegovy pill, these treatments support weight loss by reducing your appetite and helping you feel fuller for longer.
That makes it easier to stick to a calorie deficit and a healthy diet. Combined with regular exercise, this can lead to faster and more sustainable weight loss.
They belong to a group of medications called GLP-1s, which mimic a hormone your body produces naturally. Mounjaro goes a step further, as it's a dual GIP/GLP-1 receptor agonist, meaning it acts on the GIP hormone as well.
By copying these hormones, the treatments:
send signals to your brain telling it you're full, as if you've just eaten, which helps reduce your appetite
delay how quickly your stomach empties, so you feel fuller for longer
The Wegovy pill uses the same active ingredient and the same mechanism as the injection. The clever part is how it survives your stomach long enough to work. Semaglutide is combined with a carrier molecule that protects it just long enough to be absorbed into your bloodstream, at which point it acts exactly like the injected version.
What's the difference between Mounjaro and Wegovy?
Mounjaro and Wegovy injections contain different active ingredients, but both work in similar ways to help you manage your weight. Both are approved and licensed for use in the UK, though the Wegovy injection has been around for longer.
The Wegovy pill is the newest option, approved by the MHRA in June 2026 and available in the UK from July 2026.
The main differences come down to active ingredient, effectiveness, price, and how you take them.
The Wegovy injection and Wegovy pill both contain semaglutide, a GLP-1 receptor agonist.Mounjaro contains tirzepatide, a dual GIP/GLP-1 receptor agonist. Both active ingredients can help you lose weight when combined with a healthy diet and exercise plan.
GLP-1 is a hormone your body releases after eating to tell your brain you're full. It slows how quickly your stomach empties and helps lower blood sugar by improving how your body produces insulin. Semaglutide mimics this hormone, helping you feel satisfied with less food, which makes it easier to reduce your calorie intake without feeling too hungry between meals.
Mounjaro also acts on the GIP pathway, which works a little differently to GLP-1. Activating GIP helps your body release insulin after eating and may improve how your body processes fat, so you store less over time. Together, GIP and GLP-1 activity can support greater weight loss for most people.
With all three treatments, your dose is usually increased every four weeks, though you can stay on the same dose for longer if it's working well, or you want a bit more time to adjust.
Dosing scheduling
The Wegovy injection and Mounjaro come in different doses, but they're administered in the same way: once a week. The Wegovy pill, meanwhile, is taken once a day.
With all three treatments, you start on the lowest dose and gradually increase until you reach your maintenance dose. This allows your body to adjust safely, while helping to minimise side effects.
It's important to note that not everyone needs the highest dose to achieve meaningful weight loss.
Mounjaro vs Wegovy cost
While Mounjaro is more expensive, the cost of your treatment increases as you move up your dose, regardless of what treatment you’re on.
Who makes Wegovy and Mounjaro?
Mounjaro is manufactured by Eli Lilly, a North American company. The Wegovy injection and Wegovy pill are both manufactured by Novo Nordisk, a Danish company which also makes Ozempic, Rybelsus, and Saxenda.
Delivery
The tirzepatide in Mounjaro must be kept at 2 to 8°C during delivery, so your order arrives with ice packs to keep it at the right temperature.
Aside from the 7.2mg dose, the Wegovy injection can be delivered at room temperature (below 30°C), so it won't arrive in refrigerated packaging. You should still pop your pens in the fridge as soon as they arrive though, until first use.
The Wegovy pill doesn't need refrigeration at all. The manufacturer recommends storing it somewhere dry, away from moisture, so it's best to keep it out of a steamy bathroom.
How you take each treatment depends on which one you're on. Mounjaro and the Wegovy injection are both given once a week using a prefilled pen, while the Wegovy pill is a daily tablet.
How to use Mounjaro and Wegovy injection pens
Mounjaro and the Wegovy injection both come as multi-dose injectable pens, which you can use yourself at home. Each pen lasts four weeks, and all pens are prefilled, so you don't need to worry about drawing up your own medication.
The one exception is the Wegovy 7.2mg dose, which comes as four single dose pens instead. Each pen only holds one dose, which you'll use once a week, so the four pens together still give you a month's supply.
Both injections are taken in exactly the same way. You inject it once a week, on the same day and time, with or without food. Sticking to a regular schedule helps keep the treatment effective and your appetite suppressed.
How to take the Wegovy pill
Here's how to take the Wegovy pill:
Take it first thing in the morning, on an empty stomach, before eating, drinking or taking any other oral medication.
Swallow it whole with no more than 120ml of plain water, not tea, coffee, juice or sparkling water.
Wait at least 30 minutes before eating, drinking anything other than water, or taking other medications.
Don't crush, chew or split the tablet.
Try to take it at the same time every morning so it becomes part of your routine.
If you miss a dose, just skip it and take your next tablet the following morning as normal. Don't double up, as this won't help and could increase side effects. If you miss several doses in a row, speak to your prescriber before continuing.
Mounjaro vs Wegovy side effects
Wegovy side effects are similar to Mounjaro side effects. However, unlike injections, which can sometimes cause site reactions, you won’t experience this with the Wegovy pill.
Most side effects from Wegovy and Mounjaro tend to be mild and go away on their own as your body adjusts to the treatment.
If you’re struggling to manage side effects or think you may be experiencing serious ones, it’s important to speak to your prescriber or seek urgent medical help.
All three are prescription only
All three weight loss treatments are prescription-only and can only be issued by healthcare professional, like a prescribing pharmacist or doctor. This is so they can check the treatment is safe and suitable for you. You may be eligible if you:
have a BMI of 30 or above
or a BMI of 27 to 30 with a weight-related medical condition or risk factor, like prediabetes
aren’t taking any medications, or have any medical conditions, that would make it unsafe to use
don’t have an allergy to any of the ingredients
You can use our BMI calculator to check if you meet the criteria.
Is Mounjaro better than Wegovy?
Mounjaro isn’t ‘better’ than either form of Wegovy. Which one suits you best depends on things like:
how you experience side effects
your body's response to the active ingredients
whether you're on any other medications that might interact
whether you'd rather take a weekly injection or a daily tablet
If you're finding one medication difficult, another may suit you better, and you can always switch if your clinician thinks it's safe to do so.
Can you switch between treatments?
Yes, you can switch between treatments as long as your prescriber thinks it's safe and suitable. Our prescribers will advise you how to do this based on the dose of your previous treatment and how well you tolerated this.
"If you're moving from an injection to the Wegovy pill, your new dose depends on which injection strength you were on. For example, someone on the 2.4mg Wegovy injection would typically move to the 25mg pill, and someone on the 10mg Mounjaro dose would move to the 9mg pill.
"If you're switching between treatments with different active ingredients, the manufacturers recommend a full wash-out of the previous medication before starting a new one. However, many patients prefer to begin sooner to avoid a stall in their weight loss journey.
“This, however, may increase the likelihood of side effects like nausea and diarrhoea. We can discuss this as part of your consultation.
"Any switch like this should always be done under clinical supervision, since your prescriber needs to work out the right dose for you."
you're experiencing side effects that are hard to manage
you'd prefer a different price, effectiveness, or a different way of taking your treatment, like swapping a weekly injection for a daily tablet
Can you take more than one of these at the same time?
No. You shouldn't take any weight loss treatment together. Taking more than one at once increases your risk of serious side effects, and can cause you to lose weight too quickly, which can affect your health.
This is also why you need to leave a gap when switching treatments.
Which weight loss treatment is best for me?
All three have been proven safe and effective, so it's really about finding what works for you. Here's what to think about:
Suitability: When you request treatment, we review your medical history to make sure it's safe and suitable, and help you land on the safest, most effective option for your health.
Price: Your budget matters too. The Wegovy injection and the Wegovy pill both start from £99, while Mounjaro starts from £148, so cost may influence your decision.
Side effects: All the medications share similar side effects, but some are more common depending on the treatment, and people react differently to each one.
Your current medication:Mounjaro can reduce the effectiveness of oral contraception early on in treatment and when increasing your dose, so during these periods, you'd need to use alternative contraception like condoms while taking it. Both forms of Wegovy don’t have this interaction listed, so it may make either one a better choice if you rely on the pill for birth control.
Your preference: At the end of the day, it comes down to what feels right for you, including whether a daily tablet or a weekly injection fits your routine better. Our clinical team will still need to approve your choice, but they do take your preference into account.
If you're not sure, our pharmacists can help you decide.
Alternative weight loss treatments
Wegovy and Mounjaro, whether injected or taken as a tablet, aren't the only options. We can also provide weight loss tablets or capsules like orlistat or Mysimba, if these are more suitable for you.
How Chemist4U can help
Whichever weight loss medication you'd prefer, our dedicated team is here to support you every step of the way. If you need guidance, call us on 01695 474 433 or submit your request directly here.
"We're committed to making your healthcare journey as simple, safe, and convenient as possible. When you order from us, you'll benefit from expert clinical support, convenient reorder reminders, and carefully curated resources to help you maintain momentum toward your weight loss goals."
All three have shown strong results in trials. The Wegovy injection helped people lose an average of 21% or more of their starting weight after 72 weeks on the 7.2mg dose. Mounjaro helped people lose up to 22.5% after 72 weeks on the 15mg dose. Meanwhile, the Wegovy pill helped people lose up to 17% after 64 weeks, with early responders losing up to 22% on the 25mg dose.
As the trials ran for different lengths of time and weren't designed as a direct comparison, it's not possible to say for certain which is most effective.
How long do I need to stay on treatment to lose weight?
You can stay on Mounjaro, the Wegovy injection, or the Wegovy pill for as long as it takes to reach your goal weight, and you can continue afterwards to help maintain it.
Can I get these on the NHS?
Mounjaro and the Wegovy injection are available on the NHS, though access is limited and usually only through a tier 3 specialist weight management service.
Wegovy pills aren't currently available on the NHS, as NICE still needs to assess whether they're cost-effective enough to recommend.
Your GP can refer you if you meet the eligibility criteria, but waiting times can be long and vary by area.
Is the Wegovy pill the same as Rybelsus?
Both are tablets, contain semaglutide, and are made by Novo Nordisk, but they're licensed for different things. Rybelsus is licensed for type 2 diabetes, not weight loss, and comes in doses of 1.5mg, 4mg, and 9mg.
The Wegovy pill is licensed specifically for weight management, in doses of 1.5mg, 4mg, 9mg, and 25mg. Using Rybelsus for weight loss would be considered off label use, and would only happen if your prescriber thought it was appropriate for you.
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