Wegovy vs Mounjaro: UK Comparison (October 2026)

01 · The verdict

Wegovy or Mounjaro: how do they compare for weight loss?

Both are effective, licensed once-weekly injections, and neither is right for everyone. In the first large head-to-head trial, SURMOUNT-5, average weight loss was higher on tirzepatide (Mounjaro) than on semaglutide 2.4mg (Wegovy).¹⁵ Those are averages. Which medicine suits you depends on your health profile, how you tolerate it and your prescriber's advice, not the headline number alone.¹⁵

For a worked example, someone starting at 100 kg who matched the trial averages would lose about 20 kg on tirzepatide (20.2%) or about 14 kg on semaglutide (13.7%). Your own result may be higher or lower, and treatment works alongside a reduced-calorie diet and more physical activity, not instead of them.¹⁵

02 · At a glance

Wegovy vs Mounjaro comparison table

All trial figures come from SURMOUNT-5, in which 751 adults took either medicine for 72 weeks. Prices are per month (one 4-week pen) and were checked 24 October 2026. You can see current prices on the Mounjaro pen page and the Wegovy pen page.

03 · Decision factors

How to decide between Wegovy and Mounjaro

The decision rests on a handful of practical questions, and your prescriber will weigh them with you. Neither medicine is a shortcut, and you should never take both at the same time.

• Your health history: conditions, current medicines and any previous GLP-1 treatment all matter, which is why a prescriber reviews every request.
• Tolerance: if digestive side effects were hard on one medicine, tell your prescriber so the plan can be reviewed.
• Dose pace: Wegovy reaches its 2.4mg maintenance dose from week 17, while Mounjaro steps up at a minimum of 4-week intervals and many people settle on 5mg, 10mg or 15mg.¹⁸¹
• Cost and access: compare first order with first order, then standard price with standard price.
• Trial evidence: SURMOUNT-5 is the first large head-to-head trial, so it is the fairest comparison available, but trial averages do not predict your own result.

When you are ready, start your free consultation. Your answers are reviewed by a GPhC-registered prescriber, who decides whether treatment is suitable and which medicine fits.

04 · Head-to-head trial results

What the trials say about Wegovy vs Mounjaro

SURMOUNT-5 is the first large head-to-head trial of tirzepatide and semaglutide for weight loss. In it, 751 adults took tirzepatide or semaglutide 2.4mg for 72 weeks. Average loss was 20.2% of body weight on tirzepatide versus 13.7% on semaglutide 2.4mg (Wegovy), which was 22.8 kg versus 15.0 kg on average.¹⁵

The trial also reported how many people reached different thresholds. At least 10% of body weight was lost by 81.6% on tirzepatide versus 60.5% on semaglutide. At least 15% was lost by 64.6% versus 40.1%, at least 20% by 48.4% versus 27.3%, and at least 25% by 31.6% versus 16.1%.¹⁵ These figures describe groups of trial participants, not what any one person will see.

Both medicines are effective, licensed treatments. Which suits you depends on your health profile, tolerance and prescriber advice, not the headline number alone.¹⁵ Trial averages do not predict your own result, and treatment is used alongside a reduced-calorie diet and increased physical activity.

Wegovy's own trial: STEP 1

Wegovy also has its own large trial, STEP 1, which compared semaglutide with placebo rather than with Mounjaro. Adults on semaglutide 2.4mg lost on average 14.9% of body weight over 68 weeks, compared with 2.4% on placebo.⁹ Because STEP 1 was a separate trial with a different design and length, its numbers should not be set beside other trials as if they were a head-to-head result. SURMOUNT-5 is the trial that tests both medicines against each other.

Mounjaro's own trial: SURMOUNT-1

In SURMOUNT-1, 2,539 adults on tirzepatide alongside diet and exercise lost on average 15% of body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone.² At 72 weeks, 85% of participants on 5mg, 89% on 10mg and 91% on 15mg had lost at least 5% of their body weight. Half of participants on 10mg and 57% on 15mg lost at least 20%.²

For a closer look at how the evidence lines up, see our guide to semaglutide versus Mounjaro.

05 · Are they the same medicine?

Is Wegovy the same as Mounjaro?

No. They are different medicines made by different companies. Mounjaro is the brand name for tirzepatide, made by Eli Lilly. Wegovy contains semaglutide, a single-action GLP-1 medicine.¹ Both are once-weekly injections for weight management in adults, and both are prescription-only.

The key difference is the mechanism. Tirzepatide is the first treatment of its kind to activate two natural gut-hormone receptors at once: GIP and GLP-1. Together these help regulate appetite, slow how quickly the stomach empties, and improve the way the body responds to insulin.¹ In practice, most people feel fuller sooner and less hungry between meals, which supports a reduced-calorie diet. This dual action is what distinguishes Mounjaro from single-action GLP-1 medicines such as semaglutide.

How long does Mounjaro stay in the body?

Tirzepatide has a half-life of about five days, so after a final dose it takes roughly 4 to 5 weeks to clear the system. There is no way to speed this up, and nothing needs doing while it clears.¹ That matters if you are thinking about changing medicines, because your prescriber will plan the gap between them.

What about Ozempic?

Ozempic is semaglutide licensed for type 2 diabetes. It is not a UK weight-loss medicine, and prescribing it privately for weight loss is off-label. The licensed weight-management options are Mounjaro (tirzepatide) and Wegovy (semaglutide 2.4mg), so Mounjaro vs Ozempic for weight loss is really Mounjaro vs Wegovy. A regulated UK pharmacy will not supply Ozempic for weight loss.¹⁸

Other options and tablets

There is no tablet form of Mounjaro, because tirzepatide is injection-only in the UK. Two GLP-1 weight-loss tablets are now licensed: Wegovy tablets (oral semaglutide, approved by the MHRA in June 2026) and Foundayo (orforglipron, approved in August 2026). They are different medicines with their own dosing, eligibility checks and trial results, and both are prescription-only.²⁰²¹ Orlistat blocks some dietary fat absorption and produces smaller average losses. Saxenda (liraglutide) is a daily injection, unlike the once-weekly pens. For the wider picture, see Saxenda alongside both injections and how orlistat compares. Supplements marketed as a natural GLP-1, such as berberine, are not medicines and have no comparable trial evidence.

06 · Dosing and titration compared

Dosing: Wegovy 2.4mg and Mounjaro compared

Both medicines start low and step up, but the ladders differ. Wegovy pens come in 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg once weekly. The dose steps up after at least 4 weeks, reaching the 2.4mg maintenance dose from week 17, and 2.4mg is the licensed maintenance dose for weight management.¹⁸

Mounjaro comes as a pre-filled multi-dose KwikPen in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg. Everyone starts on 2.5mg once a week, which is about letting your body adjust rather than weight loss itself. After at least 4 weeks the dose increases to 5mg, and can then step up by 2.5mg at a minimum of 4-week intervals up to a maximum of 15mg weekly, depending on how you respond and tolerate it.¹

Many people settle at a maintenance dose of 5mg, 10mg or 15mg. Higher is not automatically better, and your prescriber will guide the right pace.¹

Is Wegovy 2.4mg equivalent to a Mounjaro dose?

There is no licensed equivalence. Semaglutide and tirzepatide are different medicines with different dose ladders, so a milligram figure on one does not translate to the other. If someone asks for a Mounjaro to Wegovy dose conversion, the honest answer is that a prescriber chooses the starting dose after reviewing their history.¹ Strength comparisons explain why the numbers cannot be matched.

Pace of results

Weight loss on Mounjaro is gradual by design. The first weeks on 2.5mg are an adjustment phase and losses are usually modest. Most measurable progress builds from 5mg onward, month by month. Trials measured results at 72 weeks, so think in months, not days, and judge progress by trend rather than individual weigh-ins.¹

Early loss includes water weight. If you have lost less than 5% of your starting weight after 6 months on the highest dose you can tolerate, your prescriber will discuss whether continuing or stopping is right for you. Never alter doses outside the licence: splitting pens or taking smaller, spread-out doses is not licensed, not supported by the pen's design and not endorsed by any UK regulator.

07 · Switching between them

Switching from Mounjaro to Wegovy, or the reverse

Switching is possible, but only under prescriber supervision. There is no licensed direct conversion between semaglutide and tirzepatide. In practice the previous medicine is stopped, a washout interval is observed, and the new medicine is started at a dose your prescriber judges appropriate.¹ Never run two GLP-1 medicines together.

Going from Wegovy to Mounjaro, the start is often the 2.5mg starting dose, sometimes adjusted based on your history.¹ Going from Mounjaro to Wegovy, the same principle applies: a prescriber decides the starting point and pace, and you should not try to match doses yourself. Because tirzepatide takes roughly 4 to 5 weeks to clear the system, the gap between medicines is something to agree with your prescriber rather than guess.¹

Why might someone consider switching?

Reasons vary and are individual. Common conversations with a prescriber include how a dose has been tolerated, whether progress has stalled, access and cost, and personal preference. A switch is a clinical decision, not a hack, and it works best when you bring honest information about your side effects and your results so far.

If you are thinking about changing from Mounjaro to Wegovy, write down the dose you have reached, the date of your last injection, any side effects and your current weight trend. Having this ready makes a consultation faster and more useful.

Warning signs of unsafe shortcuts

Mounjaro must not be combined with other GLP-1 medicines, unlicensed research peptides (such as retatrutide, which has no UK licence) or compounded copies. These combinations have no safety data and no regulated supply chain. If something promises faster results outside a licensed pathway, that is the warning sign.

How to start the conversation

If you already take one medicine and want to change, say so clearly in your free online consultation. List your current medicine, dose and last injection date. A GPhC-registered prescriber reviews the request and decides what is appropriate. Repeat orders re-check suitability each time, and there is no auto-shipping.

If you prefer to stay on your current treatment, your prescribing team can also review your dose rather than changing medicine. Holding a dose longer or stepping down within the licence is sometimes an option when side effects are the concern.

08 · Side effects and safety

Wegovy vs Mounjaro side effects and safety

Both medicines can cause side effects, and the most common ones are digestive. For Mounjaro, the most common effects, affecting more than 1 in 10 people, are nausea, diarrhoea, vomiting, constipation and abdominal discomfort. Common effects (up to 1 in 10) include indigestion, reduced appetite, dizziness, reflux, burping, hair shedding and injection-site reactions.¹³

Side effects are most likely when starting treatment or moving up a dose, and for most people they ease within days to a few weeks as the body adjusts.¹³ Mild nausea, altered appetite and tiredness in the first days after each injection are the commonest early effects and usually settle. For Wegovy's full list of effects, read its patient leaflet and ask your prescriber. For a side-by-side view, see our side effects guide.

Serious side effects: when to seek help

Serious side effects are uncommon but need urgent attention. Seek immediate medical help for:

• severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis);
• pain in the upper right abdomen, fever or yellowing of the skin or eyes (possible gallbladder problems);
• signs of a severe allergic reaction, such as swelling of the face or throat and difficulty breathing.

If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion). Your prescriber may need to adjust those medicines.¹ You can report any suspected side effect through the MHRA Yellow Card scheme.¹⁹

Contraception and Mounjaro

Mounjaro slows stomach emptying, which can reduce how well oral contraceptive pills are absorbed. The SmPC advises switching to a non-oral method, or adding a barrier method such as condoms, for 4 weeks after starting Mounjaro and for 4 weeks after each dose increase. This applies to the pill only; implants, coils and injections are unaffected.⁷¹

09 · Cost over a year and NHS access

Wegovy vs Mounjaro cost: the year picture

Compare like with like. Your first 2.5mg Mounjaro pen costs £129.99 with code FIRST40 (standard price £169.99), and a first Wegovy pen is £99.99. Both are first-order prices for one pen, which lasts 4 weeks.

Across the UK pharmacies we track, Mounjaro pens ranged from £143.96 to £319.99 per month across all doses when we checked on 24 October 2026. The cheapest and dearest starting pens were £143.96 and £179.99, and for the same dose providers differed by between £20 and £36.03.

Planning a Mounjaro year

If you step up after 4 weeks on each dose, your first four pens (2.5mg to 10mg) cost £879.96 at standard prices. A first year (13 pens) costs £2,399.88 if you stay on 5mg after your 2.5mg starting pen, up to £3,279.88 if you step up through every dose to 15mg. If you settle at 7.5mg, 10mg or 12.5mg, the monthly standard prices are £244.99, £274.99 and £289.99.

Those totals are before discounts. New customers save £40 on their first order with code FIRST40, and an automatic £25 reorder discount applies to every future order (code DOSE25). Payment options include Visa, Mastercard, Klarna and pay-monthly plans, with no subscriptions, and the consultation is free.

What the price includes

Prices cover the medicine, free next-day tracked delivery in temperature-controlled packaging, needles, a sharps bin and injection guidance with every order. Ongoing monthly clinical reviews are included, and the prescribing team supports dose changes and side-effect questions. Wegovy pens can be ordered through the Wegovy pen page, so check availability at the time of order. All six Mounjaro doses are in stock.

NHS or private?

Mounjaro is available on the NHS, but access is being phased in over several years. NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition, and the NHS primary-care rollout began in June 2025 with the highest-need groups first, initially BMI 40+ with four or more qualifying conditions.⁴⁶ Full rollout is expected to take years, which is why many people who meet the licensed criteria choose regulated private treatment rather than waiting. NHS access to Wegovy runs through specialist weight-management services; ask your GP.

10 · Using the pens day to day

Injecting, storing and travelling with Mounjaro

Mounjaro is injected under the skin once a week, on the same day each week, at any time of day, with or without food. Licensed sites are the stomach area (at least 5cm from the belly button), the front of the thigh, or the back of the upper arm if someone else gives the injection. Rotate the site with each dose. Each KwikPen contains four weekly doses.¹

There is no best time of day. Mounjaro works the same morning or evening, so what matters is the same day each week. Many people choose a weekend morning so early side effects fall on days off. You can change your injection day if at least 3 days (72 hours) have passed since your last dose.¹ For Wegovy, follow the instructions in its leaflet and the guidance from your prescriber.

Missed doses

If you miss a Mounjaro dose, take it as soon as you can within 4 days (96 hours) of the scheduled time, then carry on with your usual day. If more than 4 days have passed, skip the missed dose entirely and take the next one on your normal day. Never take two doses within 3 days of each other.¹

Storage

Keep Mounjaro pens in a fridge at 2 to 8°C and never freeze them. Once in use, a pen can be kept out of the fridge not above 30°C for up to 30 days, which is useful for short trips, after which it should be discarded. Keep the cap on to protect the pen from light, and never use a pen that has been frozen.¹

Travelling

You can fly with Mounjaro. Carry pens in hand luggage, because hold luggage can fall below freezing, ideally in a cool bag with the prescription label or a copy of your prescription. In-use pens tolerate up to 30 days not above 30°C, so most holidays need no special arrangements. For hot climates use an insulated pouch, and check destination rules for prescription injectables before you fly. Unopened pens stay in the fridge and keep until the expiry date printed on the box. If an unopened pen has been out of the fridge, check with the pharmacy before using it.¹

11 · How ordering works

How to order Mounjaro from EverydayMeds

EverydayMeds is a GPhC-registered UK online pharmacy (registration 9012878), and Mounjaro is supplied through official LillyDirect supply, direct from Eli Lilly's UK distribution. Genuine KwikPens are dispensed by our registered pharmacy, and all six doses from 2.5mg to 15mg are in stock. The process has four steps, and it is the same whichever dose you need.

• Free online consultation. A short health questionnaire with no charge and no obligation. The price shown is the price paid, with no hidden fees.
• Prescriber review. Your answers are reviewed by a GPhC-registered prescriber, not a scoring script. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.
• Dispensing and dispatch. Your pen is dispensed by our registered pharmacy, with same-day dispatch when ordered by 3pm.
• Delivery. Free next-day tracked delivery by DPD in discreet, temperature-controlled packaging. Saturday delivery is £14.99.

After your first order, ongoing monthly reviews, dose-titration and follow-up assessments are included, along with side-effect support. Repeat orders re-check suitability, and there is no auto-shipping. Support runs Monday to Friday, 9am to 5pm, by email at support@everydaymeds.co.uk, account portal chat or phone on 0333 207 0413.

Tracking your progress

GLPTrackr is our free companion app for tracking a GLP-1 journey, available on iOS and Android. It can help you keep a record of your doses, injection days and how you feel, which is useful to share at a review. More than 100,000 customers have been supported on their weight loss journey, and that figure describes the customers we serve rather than any result.

Declined or faulty orders

If a consultation is declined, you are refunded automatically in full. Dispensed prescription medicines cannot be returned, except if faulty, damaged or the wrong item, which you should report within 3 days. Refunds take 5 to 10 working days.

Next step

Browse all weight loss treatments to see the options, or go straight to the Mounjaro pen prices and consultation. Mounjaro (tirzepatide) is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber, and it is used alongside a reduced-calorie diet and increased physical activity. Individual results vary. This page is information, not a substitute for medical advice.