Tirzepatide vs Mounjaro Dosage: Is There a Difference? (October 2026)

01 · The short answer

Tirzepatide vs Mounjaro dosage: the verdict

Tirzepatide and Mounjaro share one dosage scheme, because they are the same medicine. Tirzepatide is the active ingredient; Mounjaro is the name Eli Lilly gives the licensed product. In the UK it is licensed for weight management in adults and for type 2 diabetes, and it comes as a pre-filled multi-dose pen (KwikPen) in six strengths.¹

So when someone asks whether the tirzepatide dose differs from the Mounjaro dose, the honest answer is no. The real questions are different ones: which strength you start on, how your prescriber steps you up, and whether the product in your hand is a genuine, licensed pen.

If you want the strengths laid out visually, our tirzepatide and Mounjaro dosage chart covers them, and Mounjaro dosage amounts goes through each pen in turn.

02 · Side by side

Tirzepatide and Mounjaro compared

03 · What actually matters

What actually decides your dose

Your dose is decided by your prescriber, not by the label on the pen. Strength is chosen to fit your health profile and how well you tolerate treatment. That is why our consultation is reviewed by a GPhC-registered prescriber rather than a scoring script, and why repeat orders re-check suitability instead of shipping automatically.

Three factors shape the plan in practice:

• Starting point. Most people begin at the lowest strength. If you are switching from another provider, your prescriber may place you at a different strength based on your history.
• Tolerance. Stepping up is a clinical decision, not a calendar one. For how steps work, see our guide to Mounjaro dosage increments.
• Where you settle. The maintenance strength varies from person to person. 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.

If you are ready to start, you can begin with a free online consultation. A new customer gets £40 off their first order with code FIRST40, and an automatic £25 reorder discount applies to every future order (code DOSE25).

04 · Why two names exist

Why the same drug has two names

Tirzepatide is the generic, or active-ingredient, name; Mounjaro is the brand. Medicines usually carry both: the ingredient name used by clinicians and in research, and the brand name on the box.

In the UK, Mounjaro is a once-weekly injectable prescription medicine made by Eli Lilly. It is licensed for weight management in adults and for type 2 diabetes.¹ Trial papers refer to 'tirzepatide'; the pharmacy label says 'Mounjaro'. Both describe the same molecule at the same strengths.

Where the wording differs, it is only because one source is a research paper and the other is a product page.

One practical point: the UK product comes only as an injection. There is no tablet form of Mounjaro, so any tablet sold as 'tirzepatide' is not the licensed product.¹

05 · The six pen strengths

The six KwikPen strengths

Mounjaro comes in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg, all as a pre-filled multi-dose KwikPen.¹ We stock all six, and they are in stock through our Mounjaro pen page, where you can see live prices.

Each pen is priced as four weeks of treatment. Standard prices at each strength, before any discount:

Your first order is £40 less at any strength with code FIRST40, and every later order is £25 off the standard price.

06 · What doses achieve

What the trials show at different doses

In SURMOUNT-1, a higher tirzepatide dose was linked to a higher average weight loss. The trial followed 2,539 adults over 72 weeks, taking tirzepatide alongside diet and exercise. They lost on average 15% of body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg, compared with 3.1% with lifestyle changes alone.²

The worked example is straight arithmetic for someone starting at 100 kg. These are trial averages, so they do not predict your own result, and individual results vary. Treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.²

The same trial reports how many people reached set thresholds. 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

A higher strength is therefore not automatically 'better' for you. The aim is the strength that works for you and that you tolerate, which is a prescriber judgement. In SURMOUNT-5, the head-to-head comparison with semaglutide 2.4mg, adults on tirzepatide lost on average 20.2% of body weight over 72 weeks versus 13.7% on semaglutide.¹⁵

07 · Tirzepatide vs Wegovy doses

How the dosing compares with Wegovy

Wegovy follows a different dose ladder from Mounjaro because it is a different medicine. Wegovy (semaglutide) pens are 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg once weekly. The dose steps up after 4 weeks on each of 0.25mg, 0.5mg, 1mg and 1.7mg, so the 2.4mg maintenance dose starts from week 17, and 2.4mg is the licensed maintenance dose for weight management.¹⁸

You cannot compare milligram numbers across the two. A 2.4mg Wegovy dose and a 2.5mg Mounjaro dose are not equivalent, because they are different molecules with different strengths and effects. Mounjaro activates two gut-hormone receptors, GIP and GLP-1, while semaglutide is a single-action GLP-1 medicine.¹

For outcomes, SURMOUNT-5 was the first large head-to-head trial of the two. In it, 751 adults took tirzepatide or semaglutide 2.4mg for 72 weeks. The average loss was 22.8 kg versus 15.0 kg, and at least 15% of body weight was lost by 64.6% on tirzepatide versus 40.1% on semaglutide.¹⁵ In the separate STEP 1 trial, adults on semaglutide 2.4mg lost on average 14.9% over 68 weeks versus 2.4% on placebo.⁹ Those two sets of numbers come from different trials and should not be read side by side.

Both are effective, licensed treatments, and which suits you depends on your health profile, tolerance and prescriber advice. See our Wegovy and Mounjaro dosage chart and the longer Wegovy vs Mounjaro dosage and results guide. You can also view the Wegovy pen.

08 · Copies and unlicensed products

Compounded copies and 'research' tirzepatide

A product sold as 'tirzepatide' that is not a Mounjaro pen is not the licensed medicine. That is where dosage confusion becomes a safety issue. 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.

Licensed Mounjaro has fixed, labelled pen strengths.

Counterfeit medicine alerts and the Yellow Card scheme are run by the MHRA; you can report suspected fake medicines or side effects there.⁷ Our Mounjaro comes through official LillyDirect supply, direct from Eli Lilly's UK distribution, as genuine KwikPens. For the next-generation question, see retatrutide vs Mounjaro dosage.

09 · Switching and washout

Switching from another GLP-1 to Mounjaro

There is no licensed direct conversion between semaglutide and tirzepatide. Switching is 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. Never run two GLP-1 medicines together.

That means you cannot work out your new dose by matching milligrams. Switching at a higher strength is something only a prescriber can decide.

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

10 · Planning dose costs

Planning what your dose will cost

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 new customer's first order is £40 less, and every later order is £25 less.

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. For other strengths, use the monthly price: £244.99 at 7.5mg, £274.99 at 10mg and £289.99 at 12.5mg. Your first 2.5mg pen costs £129.99 with code FIRST40 (standard price £169.99).

Pay monthly or with Klarna if you prefer; there are no subscriptions, and the price shown is the price paid. Our consultation is free, and delivery is free next-day tracked, with same-day dispatch when you order by 3pm.

11 · NHS access to tirzepatide

NHS access and dosing

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. 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. The medicine and strengths are the same either way; what differs is how quickly you can be assessed and supplied.

If you are not sure which route fits, our weight loss treatments overview sets out the options. Whichever you choose, treatment is used alongside a reduced-calorie diet and increased physical activity. Mounjaro is prescription-only and supplied only after an online consultation reviewed by a GPhC-registered prescriber. Individual results vary, and this page is information, not a substitute for medical advice.