Wegovy or Mounjaro or Ozempic? The UK Comparison (October 2026)

01 · The verdict

Which should you choose: Wegovy, Mounjaro or Ozempic?

For weight loss, choose between Mounjaro and Wegovy, because those are the licensed options. Ozempic is semaglutide licensed for type 2 diabetes; prescribing it privately for weight loss is off-label, and a regulated UK pharmacy will not supply it for that purpose.¹⁸

Mounjaro is licensed for weight management in adults and for type 2 diabetes.¹ Wegovy is licensed for weight management. Both are effective; which suits you depends on your health profile, tolerance and prescriber advice, not the headline number alone.¹⁵ Our guide to which is better, Mounjaro or Wegovy goes deeper.

These are trial averages; individual results vary and treatment works alongside a reduced-calorie diet and more physical activity.

02 · Cost

What do they cost?

The Mounjaro pen costs £169.99 per month at 2.5mg, rising to £299.99 at 15mg (standard prices). A new customer gets £40 off their first order at any dose with code FIRST40, and every later order is £25 off the standard price (code DOSE25). 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 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.

Across the UK pharmacies we track, Mounjaro pens range from £143.96 to £319.99 (checked 25 October 2026). You can see current Wegovy prices on the Wegovy pen page, and compare more in is Mounjaro or Ozempic cheaper.

03 · Ordering

How ordering works

Ordering takes three steps. First, complete a free online consultation, reviewed by a GPhC-registered prescriber. Second, payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full. Third, we dispense and dispatch the same day if you order by 3pm, with free next-day tracked delivery. Our Mounjaro comes directly from Eli Lilly through official LillyDirect supply.

04 · Same ingredient, different names

Wegovy and Ozempic: same ingredient, different licence

Wegovy and Ozempic both contain semaglutide, which is why people ask whether they are the same. They are sold under separate licences and doses. Wegovy is the weight-management product, with pens of 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg once weekly, stepping up after at least 4 weeks to reach 2.4mg from week 17.¹⁸

Mounjaro contains tirzepatide, a different medicine, in a pen with six strengths from 2.5mg to 15mg.¹ For more, see is Wegovy the same as Ozempic or Mounjaro and Wegovy v Ozempic.

05 · How they work

How the mechanisms differ

Tirzepatide activates two gut-hormone receptors, GIP and GLP-1. Together these help regulate appetite, slow stomach emptying and improve the body's response to insulin. 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). Tirzepatide has a half-life of about five days, so it takes roughly 4–5 weeks to clear after a final dose.¹

06 · The trial evidence

What the trials show

SURMOUNT-5 is the first large head-to-head trial of tirzepatide and semaglutide for weight loss. Over 72 weeks, 751 adults lost on average 20.2% on tirzepatide versus 13.7% on semaglutide 2.4mg. At least 15% of body weight was lost by 64.6% versus 40.1%, and average loss was 22.8 kg versus 15.0 kg.¹⁵ For someone starting at 100 kg, 20.2% is about 20 kg.

Separately, in SURMOUNT-1 (2,539 adults) people on tirzepatide lost 15% on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, versus 3.1% with lifestyle changes alone.² In STEP 1, semaglutide 2.4mg users lost 14.9% over 68 weeks versus 2.4% on placebo.⁹ Those are separate trials and should not be compared with each other. Individual results vary.

07 · Side effects and downsides

Side effects and why people stop

The main downside of Wegovy in STEP 1 was digestive side effects: 74.2% of people on semaglutide 2.4mg reported gastrointestinal effects versus 47.9% on placebo, and 7.0% stopped treatment because of side effects versus 3.1% on placebo.⁹

Report any new symptom to your prescriber and via the Yellow Card scheme.¹⁹ Our page on which is safer, Wegovy or Mounjaro covers this further.

08 · Switching and safety

Switching between them

There is no licensed direct conversion between semaglutide and tirzepatide. Switching is done under prescriber supervision: the previous medicine is typically stopped, a washout interval observed, and Mounjaro started at a dose your prescriber judges appropriate, often 2.5mg. Never run two GLP-1 medicines together.

Mounjaro must not be combined with other GLP-1 medicines, unlicensed research peptides such as retatrutide (no UK licence) or compounded copies; these have no safety data and no regulated supply chain. See switching from Ozempic to Wegovy or Mounjaro.

09 · Access: NHS and private

NHS or private access

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 primary-care rollout began in June 2025 with the highest-need groups first.⁴ 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.

Licensed use is for adults with a BMI of 30 or above, or 27 to 30 with a weight-related condition, alongside a reduced-calorie diet and more activity. See our private prescription options.

10 · Tablets and alternatives

Tablets and other alternatives

There is no tablet form of Mounjaro. Two GLP-1 weight-loss tablets are now licensed in the UK: Wegovy tablets (approved June 2026) and Foundayo (approved August 2026). They are different medicines with their own dosing and eligibility checks.²⁰²¹ See current prices on our weight loss treatments page.

"Natural GLP-1" supplements such as berberine are not medicines and have no comparable trial evidence. Anything promising faster results outside a licensed pathway is a warning sign.

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