Ozempic or Mounjaro: Which Works Better for Weight Loss? (October 2026)

01 · The verdict

Which works better: Ozempic or Mounjaro?

Mounjaro produced more weight loss on average in the first large head-to-head trial of the two active ingredients. In SURMOUNT-5, adults on tirzepatide lost on average 20.2% of body weight over 72 weeks versus 13.7% on semaglutide 2.4mg (Wegovy).¹⁵ Both are effective, licensed treatments, and which suits you depends on your health profile, tolerance and prescriber advice, not the headline number alone.¹⁵

There is an important catch in the question itself. 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 the useful comparison is Mounjaro against Wegovy. A regulated UK pharmacy will not supply Ozempic for weight loss.¹⁸

02 · Side by side

Mounjaro vs semaglutide at a glance

Reading the table: the 22.8 kg and 15.0 kg figures are trial averages, and individual results vary.¹⁵ Wegovy's own trial result is separate. In STEP 1, adults on semaglutide 2.4mg lost on average 14.9% of body weight over 68 weeks versus 2.4% on placebo.⁹ That is a placebo comparison, so it should not be set against any other trial's numbers.

03 · Decision factors

Who each option tends to suit

Mounjaro may suit adults whose prescriber judges it suitable and who are happy to step up through the dose strengths with prescriber review. In SURMOUNT-5, 64.6% of people on tirzepatide lost at least 15% of body weight versus 40.1% on semaglutide, and 48.4% lost at least 20% versus 27.3%.¹⁵

Wegovy may suit people whose prescriber prefers semaglutide, for example after a good response or a poor experience with another medicine. It is also a licensed, well-studied option: in STEP 1, 86.4% of adults on semaglutide 2.4mg lost at least 5% of body weight over 68 weeks versus 31.5% on placebo.⁹ If you currently take Ozempic for diabetes, do not change anything without your diabetes team.

Four practical factors usually decide it: the evidence for your goal, how you tolerate side effects, your other conditions and medicines, and cost. For the cost side, see our guide to whether Mounjaro or Ozempic is cheaper. All six doses are in stock.

Ready to check suitability? You can start your free consultation. It is reviewed by a GPhC-registered prescriber. Payment is taken when you place the order, and if the prescriber decides the treatment is not suitable, the order is refunded automatically in full. We supply Mounjaro through official LillyDirect supply, with free next-day tracked delivery in cold-chain packaging.

04 · How they work

How Mounjaro and semaglutide work differently

The main mechanical difference is that Mounjaro targets two gut-hormone receptors and semaglutide targets one. Tirzepatide is the first treatment of its kind to activate both GIP and GLP-1 receptors at once. 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.¹

Semaglutide, the active ingredient in both Ozempic and Wegovy, is a single-action GLP-1 medicine. Mounjaro acts on two receptors and semaglutide on one. A mechanism on paper does not tell you how you personally will respond.

Same ingredient, different licence

Ozempic and Wegovy both contain semaglutide, but they are different products with different licences. Ozempic is licensed in the UK for type 2 diabetes. Wegovy is licensed for weight management, with a maintenance dose of 2.4mg once weekly reached from week 17 after stepping up after at least 4 weeks through 0.25mg, 0.5mg, 1mg and 1.7mg.¹⁸ Mounjaro is licensed for both weight management and type 2 diabetes, and comes as a pre-filled multi-dose KwikPen in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹

That is why a regulated UK pharmacy will not supply Ozempic for weight loss: using a diabetes-licensed product for weight loss is off-label. If you want a semaglutide medicine for weight management, the licensed route is Wegovy, and you can see the Wegovy pen alongside Mounjaro.

Dosing rhythm

Both Mounjaro and Wegovy are once-weekly injections. Your prescriber chooses the dose you step to based on your response and tolerance, and reviews you along the way. 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

For a fuller side-by-side of the two licensed weight-loss injections, see is Mounjaro or Wegovy better for weight loss. Whichever medicine you consider, it works alongside a reduced-calorie diet and increased physical activity, not instead of them.

05 · Trial evidence

What the trials actually show

SURMOUNT-5 is the first large head-to-head trial of tirzepatide and semaglutide for weight loss. SURMOUNT-1 and STEP 1 each compare one medicine with placebo or lifestyle changes alone.

SURMOUNT-5: the direct comparison

In SURMOUNT-5, 751 adults took tirzepatide or semaglutide 2.4mg for 72 weeks. Average loss was 22.8 kg on tirzepatide versus 15.0 kg on semaglutide, which is 20.2% versus 13.7% of body weight.¹⁵ The proportions reaching each threshold were also higher on tirzepatide:

These are trial averages and percentages of participants. Individual results vary, and your outcome depends on dose, adherence, diet, activity and how you tolerate treatment.¹⁵

SURMOUNT-1: tirzepatide against lifestyle changes alone

In SURMOUNT-1 of 2,539 adults, people taking 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 As a worked example, for someone starting at 100 kg, 20.9% is about 21 kg.

STEP 1: semaglutide 2.4mg against placebo

In STEP 1, adults on semaglutide 2.4mg lost on average 14.9% of body weight over 68 weeks, compared with 2.4% on placebo. 69.1% lost at least 10% (versus 12.0%) and 50.5% lost at least 15% (versus 4.9%).⁹

Different trials enrol different people, run for different lengths and use different comparison groups. That is why only SURMOUNT-5 supports a direct tirzepatide-versus-semaglutide statement. When you see a page quoting an Ozempic figure beside a Mounjaro figure from separate studies, treat it with caution.

06 · Pace of results

How fast will you lose weight?

Weight loss on Mounjaro is gradual by design, so the honest answer is months rather than days. 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.¹ The trials measured results at 68 to 72 weeks, so judge progress by trend, not individual weigh-ins.

How much in 3 months?

Three months in, most people are still on the lower rungs of the dose ladder, so averages at this stage are modest compared with the headline figures. In SURMOUNT-1, average weight loss built month by month, with the full 15 to 21% averages measured at 72 weeks, not 12.² A sensible 3-month expectation on a standard titration is mid single digits as a percentage of body weight, with wide individual variation. Slower early progress does not predict failure, because the dose you respond to may still be ahead of you.

What about a fixed target in two months?

People often ask whether a specific kilogram target is realistic within two months of starting. Weight loss is not linear, so a fixed loss in two months cannot be promised. Early loss also includes water weight, so the trend over weeks matters more than any single weigh-in.¹ Be wary of any seller or product that promises a fast, specific result: dramatic weight-loss claims are a warning sign.

If you want to compare speed between the two semaglutide and tirzepatide routes, our guide on what works faster, Ozempic or Mounjaro covers it in more depth.

The first weeks

Experiences differ widely. Some people notice an appetite change and early loss in week one, while others feel little until a higher dose. Both are normal. Mild nausea, altered appetite and tiredness in the first days after each injection are the commonest early effects and usually settle.¹

Plateaus

Plateaus of a few weeks are normal and expected as the body adapts to a lower weight. Within the licence, the responses are: review food intake honestly because portions drift back up, protect protein and activity, check the basics such as sleep and alcohol, and discuss with your prescriber whether a dose step-up is appropriate if you are not yet at maximum. A plateau is not a reason to double doses or add unlicensed products.

When your prescriber reviews response

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.¹ That review is part of safe treatment, and with us ongoing monthly clinical reviews are included.

07 · Side effects

Side effects, stopping and safety questions

Both medicines commonly cause digestive side effects, and some people stop treatment because of them. In STEP 1, gastrointestinal side effects were reported by 74.2% of people on semaglutide 2.4mg compared with 47.9% on placebo, and 7.0% stopped treatment because of side effects versus 3.1% on placebo.⁹ For tirzepatide, mild nausea, altered appetite and tiredness in the first days after each injection are the commonest early effects and usually settle.¹

Why are people stopping Ozempic?

Side effects are one reason people stop: in STEP 1, 7.0% of people on semaglutide 2.4mg stopped because of them.⁹ Other reasons, such as cost, supply or a change in health goals, are personal. If you are thinking of stopping, talk to your prescriber first. Tirzepatide takes roughly 4 to 5 weeks to clear the system after a final dose.¹

What organ is Ozempic hard on?

Your medicine's patient information leaflet lists the known side effects and who should take extra care. If you have kidney, liver, pancreas or gallbladder concerns, tell your prescriber at consultation so they can assess suitability for you.

Can you smell when someone is on Ozempic?

A noticeable smell is not listed as a side effect in the UK patient leaflet. If you notice any new symptom after starting treatment, discuss it with your prescriber and report it through the MHRA Yellow Card scheme.¹⁹

What foods should I avoid?

No food is banned on Mounjaro, but many people feel worse after very fatty, fried or very sugary food, and large portions sit heavily because the stomach empties more slowly, so smaller, slower meals work better. Prioritise protein at each meal, vegetables and fibre, and regular fluids. If particular foods make nausea worse for you, mention it at your monthly review so your prescriber can advise.

Contraception and other medicines

Tirzepatide 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.¹ If you take insulin or sulfonylureas, doses may need adjusting because of the risk of low blood sugar. Never run two GLP-1 medicines together.

08 · Cost over a year

What each route costs and how the NHS fits in

Mounjaro starts at £169.99 per month (one 4-week pen) for the 2.5mg starter at our standard price. A new customer's first order is £40 less with code FIRST40 at any dose, and an automatic £25 reorder discount applies to every future order (code DOSE25). Your first 2.5mg pen therefore costs £129.99. Prices were checked 11 October 2026.

Planning the titration and the first year

If you step up after 4 weeks on each dose, your first four pens (2.5mg to 10mg) cost £959.96 at standard prices. A first year (13 pens) costs £2,711.88 if you stay on 5mg after your 2.5mg starting pen, up to £3,599.88 if you step up through every dose to 15mg. These totals are before discounts: a new customer's first order is £40 less and every later order is £25 less than the standard price. For a maintenance dose in between, the monthly standard prices are £279.99 at 7.5mg, £290.99 at 10mg and £319.99 at 12.5mg.

How that sits against the market

Across the UK pharmacies we track, Mounjaro pens ranged from £143.96 to £339.00 per month across all doses as of 11 October 2026. For the 2.5mg starting pen alone, prices ranged from £143.96 to £179.99. The gap between providers for the same dose ranged from £27 to £41, so comparing is worthwhile. Boots' Mounjaro dose prices ran from £179.00 to £339.00.

Ozempic has no price comparison here because a regulated UK pharmacy will not supply it for weight loss. Our longer guide to comparing the cost of Mounjaro and Ozempic explains the options.

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.

What our price includes

The consultation is free and the price shown is the price paid, with no hidden fees. Needles, a sharps bin and injection guidance are included with every order. Delivery is free next-day tracked (DPD, temperature-controlled, discreet), with same-day dispatch when ordered by 3pm; Saturday delivery is £14.99. You can pay by Visa or Mastercard, Klarna or pay-monthly options, with no subscriptions.

09 · Switching safely

Switching from Ozempic or Wegovy to Mounjaro

There is no licensed direct conversion between semaglutide and tirzepatide, so switching is always done under prescriber supervision. Typically the previous medicine is stopped, a washout interval is observed, and Mounjaro is started at a dose your prescriber judges appropriate. That is often the 2.5mg starting dose, sometimes adjusted based on your history.¹ Never run two GLP-1 medicines together.

If you are switching at a higher dose, tell the prescriber exactly what you have been taking and for how long. A new customer's first order at any dose is £40 less with code FIRST40, and switching at 15mg means your first order is £289.99 as a first-order price. The dose you actually start on is the prescriber's decision, not a matter of what you were on before.

Why switch at all?

Reasons people raise include wanting the medicine with the larger direct-comparison result, poor tolerance of one medicine, or a plateau on another. None of these is a reason to change on your own. If you are on Ozempic prescribed for diabetes, your diabetes team should be involved, because changing could affect blood-sugar control. Our guide to why Mounjaro works better than Ozempic for many people explains the clinical side, and how to get Ozempic or Mounjaro covers access routes.

Avoid stacking and unlicensed products

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. Anyone offering to supply without a consultation or prescription is not operating safely. You can check any UK pharmacy on the GPhC register; ours is registration 9012878.

What about tablets and "natural" options?

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 2026.²⁰²¹ They are different medicines with their own dosing, eligibility checks and trial results, and both are prescription-only. See current Wegovy tablet prices on the product page. "Natural GLP-1" supplements such as berberine are not medicines, are not regulated for this use and have no comparable trial evidence; they are low-cost supplements with no clinical oversight.

10 · Beyond the scales

Belly fat, health markers and who it is for

Weight management with these medicines is aimed at health, not only the number on the scale. In trials, weight loss on tirzepatide came with average improvements in waist size, blood pressure, cholesterol and blood-sugar measures, and most participants with prediabetes returned to normal blood-sugar levels.² These are trial-average secondary outcomes, not promises, but they are why prescribers talk about weight management as health management rather than appearance.

Who is Mounjaro licensed for?

In the UK, Mounjaro is licensed for weight management in adults and for type 2 diabetes.¹ It 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. Suitability is a clinical decision. Some people will be advised another route, and unsuitable orders are refunded automatically.

Keeping the weight off

Long-term results depend on what happens after you reach your goal, and that conversation belongs with your prescriber. Mounjaro manages weight; it does not cure the biology behind it. In SURMOUNT-4, people who stopped tirzepatide after 36 weeks regained on average 14% of body weight over the following year, while those who continued treatment lost a further 5.5% on average.¹⁴ Treat the medicine as one part of a plan that includes food, activity, sleep and review.

Support while you treat

Aftercare includes ongoing monthly reviews, dose titration and follow-up assessments by the prescribing team, plus side-effect support. Repeat orders re-check suitability, and nothing ships automatically. Our free GLPTrackr companion app (iOS and Android) helps you track your journey. Support is available Monday to Friday, 9am to 5pm, by email at support@everydaymeds.co.uk, account portal chat, or phone on 0333 207 0413. Over 100,000 customers have been supported on their weight loss journey with us.

11 · Serious side effects

Serious side effects: when to get help straight away

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 skin/eyes (possible gallbladder problems); or 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

12 · Private prescription

Getting a private prescription safely

Ordering Mounjaro privately takes four steps, and the same route applies whichever dose you start on.

• Free online consultation: a short health questionnaire, no charge and no obligation.
• Prescriber review: 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: dispensed by our registered pharmacy, with same-day dispatch when ordered by 3pm.
• Delivery: free next-day tracked delivery in temperature-controlled, discreet packaging.

You can begin with a free consultation, or browse all weight loss treatments first. If you want to understand private pathways in more detail, read our guide to private prescriptions for Ozempic or Mounjaro.

Genuine supply matters

Counterfeit and unregulated weight-loss injections are a real safety risk. We supply Mounjaro direct from Eli Lilly's UK distribution through official LillyDirect supply, and the pens are genuine KwikPens across all six doses (2.5 to 15mg). Check any pharmacy against the GPhC register, be wary of sellers offering to supply without a consultation or prescription, and report suspected counterfeits or side effects through the MHRA Yellow Card scheme.⁷¹²

Refunds and returns

Declined consultations are refunded automatically in full. Dispensed prescription medicines cannot be returned except where faulty, damaged or the wrong item, and you should contact us within 3 days. Refunds take 5 to 10 working days.

Mounjaro (tirzepatide) is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber. 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. The right medicine is the one your prescriber agrees is suitable.