Orlistat or Mounjaro: Which Is Better? (October 2026)

01 · The verdict

Which is better: orlistat or Mounjaro?

Neither is better for everyone: the right choice depends on your health profile, preferences and prescriber advice. Orlistat is a tablet that blocks some dietary fat absorption and produces smaller average losses.²⁰ Mounjaro is a once-weekly injection that acts on two gut-hormone receptors and helps most people feel fuller sooner.¹

Mounjaro tends to suit adults who meet the licensed criteria and are comfortable with a weekly injection from a pen. Our Mounjaro pen comes in six strengths from 2.5mg to 15mg, so the dose can be stepped up gradually under prescriber supervision.

Orlistat tends to suit people who prefer a tablet, want a smaller-effect option, or are not yet ready for an injectable. You can see the Xenical (orlistat 120mg) product page for details. Either way, a prescriber or pharmacist should confirm what is suitable for you.

02 · Side by side

Orlistat and Mounjaro compared

The table uses each medicine's own trial. These trials differed in length and design, so read the rows as separate results, not a head-to-head contest.

Both work alongside a reduced-calorie diet and increased physical activity, and individual results vary. Trial averages do not predict your own result.

03 · Deciding

What should decide it for you

Four factors usually decide between these two: how much weight you need to lose, how you feel about injections, your budget and your health history.

Budget matters too. Mounjaro's starting pen is £169.99 per month at standard price. A new customer's first order is £40 less with code FIRST40, and an automatic £25 reorder discount applies to every future order (code DOSE25).

Finally, health history. Our free consultation is reviewed by a GPhC-registered prescriber, who decides whether Mounjaro is suitable. If you are unsure, start your free consultation with no obligation, or compare everything on our weight loss treatments page. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.

04 · How each works

How orlistat and Mounjaro work differently

Orlistat and Mounjaro act in completely different places in the body. Orlistat is a tablet that blocks some dietary fat absorption, so its effect depends on what you eat. Mounjaro acts on two gut-hormone receptors, GIP and GLP-1, which help regulate appetite.

Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly. In the UK it is licensed for weight management in adults and for type 2 diabetes. It comes as a pre-filled multi-dose pen (KwikPen) in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹

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. In practice, most people feel fuller sooner and less hungry between meals, which supports a reduced-calorie diet.¹

This dual action distinguishes Mounjaro from single-action GLP-1 medicines such as semaglutide (Wegovy and Ozempic). If you want to see how those two compare, read our guide on Mounjaro versus Wegovy.

Why the mechanism matters in daily life

With orlistat, the approach is about what happens to the fat in meals you have already chosen to eat. With Mounjaro, the aim is that you feel less hungry and fuller sooner, so a reduced-calorie diet feels more manageable. Neither is a substitute for diet and activity. Both are used alongside them.

One practical Mounjaro point: tirzepatide has a half-life of about five days, so after a final dose it takes roughly 4–5 weeks to clear the system. There is no way to speed this up, and nothing needs doing while it clears.¹

05 · What the trials show

What the trials show for weight loss

Mounjaro's trial averages are considerably higher than orlistat's, though the two were measured in different studies. In SURMOUNT-1, 2,539 adults taking tirzepatide alongside diet and exercise lost on average 15% of their 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 These are trial averages and individual results vary.

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% of their body weight.²

As a worked example, for someone starting at 100 kg, 15% is about 15 kg, 19.5% is about 19.5 kg and 20.9% is about 21 kg. That is straight arithmetic on the trial averages, not a prediction for any one person.

Orlistat: the XENDOS trial

In the four-year XENDOS trial of 3,305 adults, people taking orlistat alongside lifestyle changes lost on average 5.8 kg, compared with 3.0 kg on placebo. The trial ran for four years, so it speaks to longer-term use.

Why not compare the two directly? SURMOUNT-1 and XENDOS differed in length, populations and design, so setting one number against the other as a head-to-head result would mislead. Orlistat works differently and produces smaller average losses.

What about quick results?

Many people ask how much they can lose in two weeks on orlistat, or how to lose a set amount in 12 weeks. The trials report averages over 72 weeks and four years. Any source that promises fast or specific results is a warning sign. Treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.²

06 · Other injectable options

If neither feels right: other licensed options

Orlistat and Mounjaro are not the only licensed choices, and the evidence for the injectables is worth knowing. SURMOUNT-5 is the first large head-to-head trial of tirzepatide and semaglutide for weight loss. In it, 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; which suits you depends on your health profile, tolerance and prescriber advice, not the headline number alone.

More detail from SURMOUNT-5, which involved 751 adults over 72 weeks: at least 10% of body weight was lost by 81.6% on tirzepatide versus 60.5% on semaglutide; at least 15% 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%. Average loss was 22.8 kg versus 15.0 kg.¹⁵

Wegovy

In the STEP 1 trial, adults on semaglutide 2.4mg (Wegovy) lost on average 14.9% of body weight over 68 weeks, compared with 2.4% on placebo.⁹ In STEP 1, 86.4% lost at least 5% of body weight (31.5% on placebo), 69.1% at least 10% (12.0%) and 50.5% at least 15% (4.9%). Gastrointestinal side effects were reported by 74.2% on semaglutide 2.4mg versus 47.9% on placebo, and 7.0% stopped treatment because of side effects versus 3.1% on placebo.⁹

Wegovy titration runs 0.25mg, 0.5mg, 1mg, 1.7mg, then 2.4mg, four weeks each, reaching the maintenance dose from week 17. Our page on what is better Wegovy or Mounjaro goes deeper, and orlistat or Wegovy covers the tablet comparison.

Saxenda and Rybelsus

Saxenda (liraglutide) is a daily injection supplied at 6mg per millilitre, unlike once-weekly Mounjaro and Wegovy. See Mounjaro or Saxenda and ask your prescriber. For the oral diabetes medicine, see Rybelsus or Mounjaro.

On Ozempic: it is semaglutide licensed for type 2 diabetes, not a UK weight-loss medicine, and prescribing it privately for weight loss is off-label. A regulated UK pharmacy will not supply Ozempic for weight loss.

07 · Safety compared

Is orlistat safer than Mounjaro?

Safety depends on your health history, other medicines and how each is used. Both are licensed prescription options, and both should be started with professional advice. Reading the patient information leaflet before starting is essential for either.¹³

Mounjaro is prescription-only and is supplied only after an online consultation reviewed by a GPhC-registered prescriber. It is used alongside a reduced-calorie diet and increased physical activity. The full list of side effects, warnings and who should not use it is in the patient information leaflet.¹³ Mounjaro is not suitable for everyone. You should not take it if you are allergic to tirzepatide or any of its ingredients, and it should not be used during pregnancy or while trying to conceive. Your prescriber will take extra care, or may recommend against treatment, if you have a history of pancreatitis, severe gut or digestive disease, diabetic retinopathy, or gallbladder problems. Always share your full medical history and medicine list during consultation. Mounjaro should be stopped at least one month before trying to conceive. If you become pregnant during treatment, stop the medicine and tell your prescriber promptly.

For context on how side effects are measured, the STEP 1 trial reported gastrointestinal side effects in 74.2% of people on semaglutide 2.4mg versus 47.9% on placebo, with 7.0% stopping because of side effects versus 3.1% on placebo.⁹

What this means in practice

Rather than ranking safety in the abstract, use these questions with your prescriber or pharmacist:

• Which other medicines and conditions do I have that might affect the choice?
• What side effects should I expect, and when should I seek help?
• How will my dose be reviewed and adjusted over time?

Our prescribing team offers ongoing monthly reviews, dose-titration and follow-up assessments, plus side-effect support. If you have a new or worrying symptom on any medicine, discuss it with your prescriber, and you can report suspected side effects through the Yellow Card scheme.¹⁹

Be wary of anything that promises faster results outside a licensed pathway. Mounjaro must not be combined with other GLP-1 medicines, unlicensed 'research' peptides or compounded copies, because these have no safety data and no regulated supply chain.

08 · Cost over a year

What does each cost over a year?

Mounjaro's cost depends on your dose, and it is shown live so you can see what you would actually pay. A Mounjaro pen is one 4-week supply. The standard pen prices are £169.99 (2.5mg), £218.99 (5mg), £279.99 (7.5mg), £290.99 (10mg), £319.99 (12.5mg) and £329.99 (15mg), checked 10 October 2026.

A new customer gets £40 off their first order at any dose with code FIRST40, including people switching to us at a higher dose. After that, every future order is £25 off the standard price automatically (code DOSE25). Your first 2.5mg pen costs £129.99 with the code (standard price £169.99). Switching at 15mg? Your first order is £289.99.

Those totals are before discounts: a first order is £40 less and every later order £25 less. For other maintenance doses, use the monthly price: £279.99 at 7.5mg, £290.99 at 10mg, £319.99 at 12.5mg.

Where that sits in the market

Across the UK pharmacies we track, the cheapest and dearest Mounjaro pen at any dose ranges from £143.96 to £339.00 per month, and the gap between providers for the same dose runs from £27 to £41. Boots' Mounjaro doses run from £179.00 to £339.00. Checked 10 October 2026.

For the current orlistat price, see the Xenical product page. A fair comparison looks at cost against what you expect to get, not just the monthly figure. Consultation is free, the price shown is the price paid, and there are no hidden fees. Payment options include Visa, Mastercard, Klarna and pay-monthly plans, with no subscriptions.

09 · NHS or private

NHS or private: how do you get each?

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.⁵

The practical first step is to ask your GP what is available to you locally and whether you fall into a current NHS group. If you do not, or you would rather not wait, a private route through a registered pharmacy is an option. Our pharmacy is GPhC-registered (9012878), and you can check it on the GPhC register.

What private treatment includes with us

• A free online consultation, with no charge and no obligation.
• Review by a GPhC-registered prescriber, not a scoring script.
• Genuine KwikPens via official LillyDirect supply, with all six doses stocked and currently in stock.
• Needles, sharps bin and injection guidance with every order.

The key point is that both routes involve a clinical decision about whether treatment is appropriate for you.

If you are unsure whether to use a medicine at all, our guide on losing weight naturally or with Mounjaro covers the trade-offs without pushing you either way.

One more note: repeat orders re-check suitability, so there is no auto-shipping. You stay in control of each pen you receive, and the prescribing team reviews how you are getting on.

10 · Alternatives and shortcuts

Tablets, supplements and 'poor man's Ozempic'

There is no tablet form of Mounjaro: tirzepatide is injection-only in the UK. If you want a tablet, there are now two licensed GLP-1 weight-loss tablets: Wegovy tablets (oral semaglutide, made by Novo Nordisk), approved by the MHRA in June 2026, and Foundayo (orforglipron, made by Eli Lilly), approved in August 2026.²⁰²¹ They are different medicines from Mounjaro, with their own dosing, eligibility checks and trial results, and both are prescription-only.

What is the 'poor man's Ozempic'?

The phrase is used online for low-cost supplements such as berberine, sometimes called 'nature's Ozempic'. These supplements are not medicines, are not regulated for this use and have no comparable trial evidence.²⁰ They are available cheaply without assessment and carry no clinical oversight. Dosing is not standardised. Dramatic weight-loss claims attached to them should be treated with caution.

Retatrutide and 'stacking'

Retatrutide has no UK licence. Mounjaro must not be combined with unlicensed 'research' peptides such as it, with other GLP-1 medicines, or with 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. Our page on retatrutide or Mounjaro explains more.

What is better than Mounjaro?

For most people the honest answer is that nothing is universally better. SURMOUNT-5 showed larger average loss on tirzepatide than on Wegovy, but both are effective, licensed treatments and the right one depends on your health, tolerance and prescriber advice.¹⁵

For a fuller view of orlistat brands, see our guide to which is better, Alli or orlistat.

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 · Switching and ordering

Switching to Mounjaro and how ordering works

If you are moving between weight-loss medicines, do it under prescriber supervision. There is no licensed direct conversion between semaglutide and tirzepatide. Typically the previous medicine is stopped, a washout interval is observed, and Mounjaro is started at a dose your prescriber judges appropriate, often the 2.5mg starting dose and sometimes adjusted based on your history. Never run two GLP-1 medicines together. 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.

How ordering works

1. Free online consultation: a short health questionnaire, with no charge and no obligation.
2. Prescriber review: a GPhC-registered prescriber reviews it. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.
3. Dispensing and delivery: dispensed by our registered pharmacy, with same-day dispatch when ordered by 3pm, then free next-day tracked delivery (DPD, temperature-controlled, discreet). Saturday delivery is £14.99.

You can start your free consultation whenever you are ready. Over 100,000 customers have been supported on their weight loss journey with us.

Support after you order

Aftercare includes ongoing monthly reviews, dose-titration and follow-up assessments by the prescribing team, and side-effect support. Our support team is available Monday to Friday, 9am to 5pm, at support@everydaymeds.co.uk, via the account portal chat, or on 0333 207 0413. GLPTrackr is a free companion app for tracking your GLP-1 journey on iOS and Android.

On returns: declined consultations are refunded automatically in full. Dispensed prescription medicines cannot be returned except if faulty, damaged or the wrong item, and you should contact us within 3 days. Refunds take 5–10 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.