Mounjaro vs Wegovy: Which Is Right for You?

If you're researching this for the first time, you're not alone.

Most people spend weeks reading about GLP-1 medications before they decide.

That's reasonable. These are prescription treatments with real results and real side effects, and choosing between two options that work in similar ways is genuinely difficult.

This article is not a recommendation.

The final decision on whether either treatment is right for you is made by a GMC-registered prescriber after reviewing your medical history.

We've written this guide the same way our prescribers handle a consultation. Straight answers, tangible clinical data, no hype.

Our goal here is to help you have an informed conversation with your doctor so that you can choose the best for your health.

If GLP-1 medications are completely new to you, our complete UK guide to GLP-1 medications covers the basics first.

Before we begin: A bit about OnlineClinic

OnlineClinic has been operating since 2011 and has treated more than 2.1 million patients.

The pharmacy is registered with the General Pharmaceutical Council (GPhC), our prescribers are registered with the General Medical Council (GMC), and the service is regulated by the Care Quality Commission (CQC).

On Trustpilot, OnlineClinic has a rating of 4.6 out of 5 based on 6,114 reviews.

If you have any questions about Mounjaro or Wegovy during your treatment, you can message a prescriber through your account without a charge.

Trial results are from peer-reviewed publications referenced at the end of this article.

Your gut naturally releases hormones called GLP-1 and GIP after you eat.

These hormones tell your brain you're full and slow how quickly your stomach empties.

The GLP-1 medications, such as Mounjaro and Wegovy, mimic these hormones, but at a much stronger and longer-lasting level than your body produces on its own.

The practical effect:

• You feel full sooner during meals
• You feel full for longer between meals
• Cravings, especially for high-calorie foods, tend to reduce
• Stomach emptying slows down

Where they differ:

Wegovy targets the GLP-1 receptor only.

Mounjaro targets both GLP-1 and GIP.

The dual action is part of why Mounjaro produces slightly greater average weight loss.

Wegovy compensates by being available at a higher milligram dose.

The 7.2mg dose is three times the previous 2.4mg dose and substantially narrows the gap.

Between Mounjaro and Wegovy, which weight loss drug helps you lose more weight? We’ve established an answer from clinical trials and data.

Mounjaro vs Wegovy: the head-to-head comparison

The SURMOUNT-5 trial directly compared Mounjaro with Wegovy in 751 adults with obesity (without diabetes) over 72 weeks. The results, published in the New England Journal of Medicine in May 2025:

• Mounjaro (upto 15mg): 20.2% average weight loss
• Wegovy (upto 2.4mg — the highest dose available at the time of the trial): 13.7% average weight loss

An important caveat: SURMOUNT-5 compared Mounjaro against the older 2.4mg Wegovy dose, not the new 7.2mg dose.

As of May 2026, no published trial has directly compared Mounjaro 15mg with Wegovy 7.2mg.

Based on the individual trials, the gap between the two highest doses is around 1–2 percentage points of body weight loss, which is much closer than the older SURMOUNT-5 comparison suggested.

A second caveat: Trial averages are averages.

Some people on Wegovy lose more than they do on Mounjaro.

Response to GLP-1 medications varies between individuals, and no one can tell you in advance how you specifically will respond.

Here’s the key thing you should know about Wegovy. Since mid-2024, Wegovy has a UK regulatory status that Mounjaro doesn't.

What the SELECT trial showed

The SELECT trial enrolled 17,604 adults with established cardiovascular disease and a BMI of 27 or above.

Half received Wegovy 2.4mg, half received a placebo, both alongside standard care. Participants were followed for an average of around three years.

The headline result: Wegovy reduced the risk of major adverse cardiovascular events (heart attack, stroke, or cardiovascular death) by 20% compared with placebo. Read the trial

What the UK regulator decided

• MHRA, July 2024: approved Wegovy 2.4mg for reducing the risk of cardiovascular events in adults with established cardiovascuh3lar disease and a BMI of 27 or above. MHRA announcement
• NICE, April 2026: recommended Wegovy on this indication. It's the first and only GLP-1 medication NICE has recommended for cardiovascular risk reduction in the UK. NICE recommendation

What this means practically

If you have an established cardiovascular disease, a history of heart attack, stroke, or peripheral artery disease, taking Wegovy reduces your risk of a future cardiovascular event.

For some patients in this group, the cardiovascular benefit matters as much as the weight loss.

Mounjaro has its own ongoing cardiovascular outcomes trial (SURPASS-CVOT), but the results are not yet published.

Mounjaro does not currently hold a UK licence for cardiovascular risk reduction.

If cardiovascular protection is a relevant factor for you, that's a meaningful point in Wegovy's favour today.

We cover the cardiovascular evidence in more depth in Wegovy and heart disease: the UK cardiovascular indication explained.

Both medications have similar side effect profiles because they work in similar ways.

The most common side effects are gastrointestinal and tend to be worse in the first few weeks, as the dose increases.

We cover the timeline in detail in Mounjaro side effects week by week.

Common side effects (more than 1 in 10 people)

• Nausea: most common in the first 4–8 weeks
• Diarrhoea
• Constipation
• Vomiting: less common but real
• Reduced appetite: which is partly the point, but it can feel uncomfortable at first
• Tiredness

Less common but serious

• Inflammation of the pancreas (pancreatitis): Rare but serious. Stop and seek medical advice if you get severe stomach pain that doesn't go away
• Gallbladder problems: Rapid weight loss of any kind can trigger gallstones
• Low blood sugar: Particularly if you're taking other diabetes medications
• Allergic reactions: Rare but require immediate attention

What helps with the early side effects

These side effects might sound quite intimidating at first. But don’t let that stop you from starting your GLP-1 treatment.

Here are some easy, practical tips that can help you manage the side effects from your treatment:

• Start at the lowest dose and gradually increase the doses. Both treatments are designed this way for a reason to allow your body to adjust to each dose over 1-2 weeks before the next increase.
• Eat smaller meals. Slowed stomach emptying may make it hard for you to have large meals.
• Avoid very high-fat foods, especially in the first few weeks after taking your dose.
• Dehydration can cause constipation. Hydrate well to manage the side effect.
• Tell your prescriber if a side effect doesn't ease after a few weeks. Sometimes staying on the current dose for an extra cycle or going back to a lower dose can help.

Our prices:

• Wegovy starts at £69.99 for the starter dose. Higher doses, including the new 7.2mg, cost more.
• Mounjaro starts at £139.99 for the 2.5mg starter pen. The 15mg pen costs £263.99.

Every price includes the prescription, the consultation, the packaging, and next-day delivery. There are no hidden fees.

Both treatments have a subscription option with savings on repeat deliveries. You can pause, skip, or cancel at any time from your account.

Neither Mounjaro nor Wegovy are suitable if you:

• Are allergic to tirzepatide or semaglutide.
• Are pregnant, planning to become pregnant, or breastfeeding.
• Have a personal or family history of medullary thyroid carcinoma (a rare thyroid cancer).
• Have Multiple Endocrine Neoplasia syndrome type 2.
• Have had a serious allergic reaction to either medication's active ingredient.

You should discuss with a prescriber if you have:

• A history of pancreatitis or gallbladder disease
• Severe kidney or liver problems
• Diabetic retinopathy (eye problems linked to diabetes)
• A history of eating disorders
• Other diabetes medications, particularly insulin or sulphonylureas
• Oral contraception: GLP-1 medications can reduce absorption; see Mounjaro and contraception for what to discuss with your prescriber

Eligibility for treatment also requires:

• BMI of 30 or above, or
• BMI of 27 or above with at least one weight-related health condition (type 2 diabetes, high blood pressure, sleep apnoea, fatty liver disease, PCOS, osteoarthritis, or heart disease)

If neither applies, GLP-1 medication isn't the right treatment. Our prescribers will explain why and what alternatives might help.

There's no single right answer. The choice usually comes down to a few practical factors.

Wegovy tends to be the better choice if:

• You have established cardiovascular disease and a BMI of 27 or above. The NICE-recommended cardiovascular indication is unique to Wegovy in the UK
• Cost is a meaningful factor. Wegovy is typically the lower-priced option, particularly at starting doses
• You've responded well to GLP-1-only medications in the past
• The 7.2mg dose suits your prescriber's clinical judgement

Mounjaro tends to be the better choice if:

• You're prioritising the highest average weight loss possible
• You've tried Wegovy and not lost enough weight on the maximum dose
• You have a higher starting BMI and want the option of dual GLP-1/GIP action

Either may be appropriate if:

• You're starting GLP-1 treatment for the first time and have no particular preference
• Both options fit within your budget
• Your prescriber recommends either after reviewing your medical history

The prescriber's role is an important one here.

They look at your full medical history, current medications, BMI, and any health conditions, and they advise on which medicine is suitable for you.

Straightforward. From start to finish:

1. Fill in a short medical questionnaire. It takes 5–10 minutes.

   The questions cover your medical history, current medications, weight and height, and any conditions or allergies.

   The prescriber uses these questions to ensure that the treatment is safe for you.

2. A GMC-registered prescriber reviews your answers. If they need more information, they message you through your account.

   No phone tag, no in-person visit.

3. If the treatment is approved, it's dispensed and dispatched.

   Next-day delivery, with temperature-controlled packaging when required, plus all the supplies you need (needles, sharps bin, full patient information leaflet).

   Mounjaro pens ship in cold packaging.

   Wegovy pens are stable below 30°C and ship in standard insulated packaging. Hence, no ice pack required.

4. If the treatment isn't approved, the prescriber explains why.

   They may suggest an alternative or recommend you discuss with your GP. You're not charged for treatment that isn't issued.

Our pharmacy is registered with the General Pharmaceutical Council (GPhC).

Our prescribers are registered with the General Medical Council (GMC). The service is regulated by the Care Quality Commission (CQC).

These are the regulators that oversee every UK pharmacy, ensuring it operates to the same clinical standards.