Difference in Mounjaro Doses: 2.5mg to 15mg Explained (October 2026)

01 · The short answer

The difference in Mounjaro doses at a glance

The difference between Mounjaro doses is the amount of tirzepatide in each weekly injection, and the job each step does in your treatment plan. 2.5mg lets your body adjust. 5mg is where most measurable progress begins to build. Higher doses are used only if your prescriber judges you need them and you tolerate them.¹

Everyone starts on 2.5mg once a week. 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 (7.5mg, 10mg, 12.5mg) to a maximum of 15mg weekly, depending on how you respond and tolerate it.¹¹¹ Many people settle at a maintenance dose of 5mg, 10mg or 15mg. Higher is not automatically better, and your prescriber guides the pace.

These are trial averages from SURMOUNT-1 (2,539 adults, tirzepatide alongside diet and exercise, against 3.1% with lifestyle changes alone). Individual results vary, and treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.²

02 · Choosing a dose

Which dose suits which person?

You do not pick your own dose; your prescriber decides it from your response and tolerance. In practice, a new patient starts at 2.5mg, a person who has settled well may stay at 5mg, and others move up through 7.5mg and 10mg. Some reach 12.5mg or 15mg. The right dose is the lowest one that works for you without troublesome side effects, and that varies widely from person to person.¹

If you are moving to us from another provider at a higher dose, your prescriber reviews your history before supplying the strength you are currently on. You can begin with a free online consultation, which is reviewed by a GPhC-registered prescriber and has no obligation. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.

03 · Cost

What the dose differences mean for cost

Each dose is a separate monthly pen at its own standard price, so moving up a step changes your bill. On the Mounjaro pen page, the 2.5mg pen is £169.99 per month (about £42.50 per week), 5mg is £218.99, 7.5mg is £279.99, 10mg is £290.99, 12.5mg is £319.99 and 15mg is £329.99. These are standard prices, checked 10 October 2026.

New customers save £40 on their first order at any dose with code FIRST40, and an automatic £25 reorder discount applies to every future order (code DOSE25). Switching at 15mg? Your first order is £289.99, a first-order price. The page on Mounjaro price differences goes further into how costs compare.

04 · How the dose ladder works

How the Mounjaro dose ladder works

The Mounjaro dose ladder is a fixed sequence of six weekly strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg. Each KwikPen contains four weekly doses of a single strength, so one pen covers one four-week step.¹

Everyone begins on 2.5mg once a week. That starting dose is about letting your body adjust, not about weight loss itself. After at least 4 weeks, the dose increases to 5mg. From there it can step up by 2.5mg, at a minimum of 4-week intervals, through 7.5mg, 10mg and 12.5mg, to a maximum of 15mg weekly. Whether you move up depends on how you respond and tolerate each step.¹¹¹

The words "at least" and "minimum" matter. Four weeks is the earliest point you can step up, not a schedule you must follow. Your prescriber can hold you on a dose for longer if you are still adjusting, or if you are already getting what you need. Many people settle at a maintenance dose of 5mg, 10mg or 15mg, and there is no requirement to climb to the top.¹

What stays the same at every dose

The medicine itself does not change as you move through the ladder. Tirzepatide activates two natural gut-hormone receptors at once, GIP and GLP-1. Together these help regulate appetite, slow how quickly the stomach empties and improve how the body responds to insulin. Most people feel fuller sooner and less hungry between meals, which supports a reduced-calorie diet.¹ That mechanism is the same at 2.5mg and 15mg; what differs is how much of the medicine is delivered each week. If you want to understand the active ingredient itself, our page on the tirzepatide and Mounjaro difference explains the brand and generic names.

Same injection, same routine

The routine does not change between doses. You inject once a week, under the skin, on the same day each week, at any time of day, with or without food.¹ Only the number in the pen's dose window changes when you start a new pen. Because each pen is a single strength, you will normally receive a new pen for each step rather than adjusting one pen.

Why the ladder is gradual

Starting low and stepping up is the licensed design for tolerability. The commonest early effects are mild nausea, altered appetite and tiredness in the first days after each injection, and these usually settle.¹³ Ask the prescribing team before changing anything yourself.

05 · 2.5mg and 5mg explained

2.5mg and 5mg: the starting doses

The difference between 2.5mg and 5mg is purpose. 2.5mg is the introductory dose, used for at least 4 weeks so your body can adjust, while 5mg is the first step used for treatment.¹

2.5mg: the adjustment dose

Everyone starts here, whatever their starting weight or health history. This dose is about tolerability rather than weight loss itself. Experiences differ widely. Some people notice appetite change and early loss in week one; others feel little until a higher dose. Both are normal. Early loss includes water weight, so the trend across weeks matters more than any single weigh-in.¹

The commonest early effects are mild nausea, altered appetite and tiredness in the first days after each injection, and they usually settle. Many people choose a weekend morning to inject so any early side effects fall on days off. There is no best time of day: Mounjaro works the same morning or evening, with or without food. What matters is injecting on the same day each week.¹

5mg: the first step up

After at least 4 weeks on 2.5mg, the dose increases to 5mg. Most measurable progress builds from 5mg onward, month by month. In the SURMOUNT-1 trial, adults taking 5mg alongside diet and exercise lost on average 15% of their body weight over 72 weeks, and 85% of participants on 5mg had lost at least 5% of their body weight. Those figures are trial averages and individual results vary.²

For perspective, as a worked example, for someone starting at 100 kg, 15% is about 15 kg. That is straight arithmetic from the trial percentage, not a prediction of what you will lose or how quickly.

Staying at 5mg

5mg is one of the common maintenance doses. A person who is responding and tolerating treatment may reasonably remain on it, and a prescriber will not push you up the ladder simply because higher strengths exist.

If you are unsure how fast your own results should be arriving, remember that weight loss on Mounjaro is gradual by design. Think in months, not days, and judge progress by the trend rather than individual weigh-ins.¹

06 · 7.5mg to 12.5mg

7.5mg, 10mg and 12.5mg: the middle of the ladder

The middle doses are the 2.5mg steps between 5mg and the 15mg maximum, used when your prescriber judges that a higher dose is worthwhile and you are tolerating the current one. Each step requires at least 4 weeks at the previous strength.¹

7.5mg: the intermediate step

7.5mg is the first increment above 5mg. It is not a maintenance dose in the list of common settling points, which are 5mg, 10mg and 15mg, but that is a description of where many people end up, not a rule.

10mg: a common maintenance dose

In SURMOUNT-1, adults on 10mg lost on average 19.5% of their body weight over 72 weeks, and 89% of participants on 10mg lost at least 5% of their body weight. Half of participants on 10mg lost at least 20% of their body weight.² Worked example: for someone starting at 100 kg, 19.5% is about 19.5 kg. Again, this is arithmetic on a trial average, and your own result will differ.

Is 10mg "a lot"? It sits in the upper-middle of a ladder that runs to 15mg, and it is a dose many people settle at. Whether it suits you depends on response and tolerance, not on whether the number sounds large. Higher is not automatically better.¹

12.5mg: the last step before the maximum

12.5mg is the final increment before the 15mg ceiling. It is part of the licensed ladder, but it is not among the doses people most commonly settle at.

Moving between doses

Every move up is a prescriber decision based on how you are responding. Many readers ask whether they can jump between strengths in no particular order; our page on whether you can alternate Mounjaro doses covers that question, and the short version is to follow your prescriber's plan rather than improvise.

Because the steps are small and gradual, you can usually tell how a new dose sits with you within the first days after the first injection. Note any change in nausea, appetite or tiredness and raise it at your next review rather than waiting.

07 · 10mg versus 15mg

10mg versus 15mg: what the trial shows

The difference in trial averages between 10mg and 15mg is small compared with the difference between lifestyle changes alone and any tirzepatide dose. In SURMOUNT-1, people on 10mg lost on average 19.5% of body weight over 72 weeks, while those on 15mg lost 20.9%, against 3.1% with lifestyle changes alone.²

These are trial averages, and individual results vary. Treatment works alongside a reduced-calorie diet and increased physical activity.²

Reading the numbers honestly

Each step up in the table shows a larger average. Whether the extra average benefit is worth it for you is a conversation for your prescriber, because it depends on your tolerance and what you are already achieving.

Worked example: for someone starting at 100 kg, 20.9% is about 21 kg, and 19.5% is about 19.5 kg.

What 15mg means in practice

15mg is the maximum licensed weekly dose. Reaching it means you have passed through every earlier step, each held for at least four weeks. It is a common maintenance dose, but it is not a goal in itself. If you are switching to us already on 15mg, your prescriber will review your history and suitability before supplying it.

Response review

Your prescriber reviews how treatment is going. If you have lost less than 5% of your starting weight after 6 months on the highest dose you can tolerate, they will discuss whether continuing or stopping is right for you.¹ That is a safeguard against staying on a dose that is not helping, and it applies at whatever dose is your highest tolerated one.

08 · Is higher better?

Is a higher Mounjaro dose always better?

No, a higher dose is not automatically better, and the licence and prescribers treat it that way. The aim is the dose that works for you at a level you tolerate, which for many people is 5mg, 10mg or 15mg.¹

Why people settle at different doses

People respond differently, and tolerance varies. Someone who feels fuller sooner and is losing weight steadily at 5mg has less reason to climb than someone whose progress has stalled. Trial averages are only averages: in SURMOUNT-1, results at each dose sat around a mean, and individuals fell on either side of it.² Trial averages do not predict your own result.

Dose versus other medicines

People often ask how Mounjaro doses compare with Ozempic or Wegovy. The milligram numbers belong to each medicine's own ladder, so they cannot be matched line for line. Wegovy (semaglutide) uses pens of 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg once weekly, stepping up after at least 4 weeks and reaching the 2.4mg maintenance dose from week 17.¹⁸ Mounjaro's ladder runs 2.5mg to 15mg. Our page on the Mounjaro and Ozempic difference lays out how the two compare, and a prescriber advises on any switch.

SURMOUNT-5 is the first large head-to-head trial of tirzepatide and semaglutide for weight loss. 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 In the separate STEP 1 trial, adults on Wegovy lost on average 14.9% of body weight over 68 weeks, compared with 2.4% on placebo.⁹ Both are effective licensed treatments, and which suits you depends on your health profile, tolerance and prescriber advice, not the headline number alone.

The case for holding a dose

Holding a dose longer is a legitimate, licensed choice. That is different from improvising your own schedule.

A realistic pace

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.¹

09 · Dose-related routines

Missed doses, injection day and storage at each dose

The rules for missed doses, changing your day and storing pens are the same at every strength, so they carry over as your dose changes.¹

If you miss a 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 This matters when you are mid-titration: a missed dose does not mean you jump a strength to catch up, and it does not change the dose in your pen.

Changing your injection day

You can change your weekly injection day if needed, as long as at least 3 days (72 hours) have passed since your last dose.¹ Many people pick a day when they will remember, such as a weekend morning, and keep to it. What matters is consistency, not the clock time.

Storing pens

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 at a temperature not above 30°C for up to 30 days after first use, which is useful for short trips, and must then be thrown away. Keep the cap on to protect the pen from light, and never use a pen that has been frozen.¹

Because each pen holds four weekly doses, a pen at any strength lasts four weeks if you inject weekly, within the 30 days a pen in use can be kept out of the fridge at a temperature not above 30°C. Unopened pens should 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 rather than relying on a remembered day limit; figures circulating online often come from other countries' labels.¹³

Travelling with higher doses

You can fly with Mounjaro at any dose. 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. For hot climates use an insulated pouch, and check destination rules for travelling with prescription injectables before you fly.¹

Stopping or pausing

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 Speak to your prescriber before pausing or stopping so the plan for restarting is clear.

10 · Dose costs over a year

Planning dose costs over a year

Your yearly Mounjaro cost depends on which dose you settle at, because each strength has its own monthly pen price. At standard prices, if you step up after 4 weeks on each of 2.5mg, 5mg, 7.5mg and 10mg, your first four pens cost £959.96. A new customer's first order is £40 less, and every later order is £25 less.

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. Those totals are at standard prices, before discounts. For anyone settling at another strength, the monthly pen price is the useful figure: £279.99 for 7.5mg, £290.99 for 10mg and £319.99 for 12.5mg. Each is a monthly pen price and not a year cost.

How the market compares

Across the UK pharmacies we track, the cheapest and dearest Mounjaro pens across all doses and providers range from £143.96 to £339.00 per month (checked 10 October 2026). The starting 2.5mg pen ranges from £143.96 to £179.99 per month across those same pharmacies. For the same dose, the gap between providers runs from £27 to £41. Boots' Mounjaro dose prices run from £179.00 to £339.00 per month. Our guide to the price difference between Mounjaro and Wegovy covers the other common comparison.

What the price includes

The consultation is free, and the price shown is the price paid, with no hidden fees. Delivery is free next-day tracked delivery in temperature-controlled packaging, with same-day dispatch when ordered by 3pm. Saturday delivery is £14.99. Payment options include Visa, Mastercard, Klarna and pay-monthly options, with no subscriptions. Repeat orders re-check suitability, and nothing ships automatically.

All six doses are in stock, supplied through official LillyDirect supply direct from Eli Lilly's UK distribution as genuine KwikPens. Ongoing monthly reviews, dose titration and follow-up assessments by the prescribing team are part of the service.

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 Mounjaro slows stomach emptying, which can reduce how well oral contraceptive pills are absorbed. Switch to a non-oral method, or add a barrier method (such as condoms), for 4 weeks after starting Mounjaro and for 4 weeks after each dose increase. Mounjaro must not be used during pregnancy, and it should be stopped at least one month before trying to conceive.

12 · NHS and private access

NHS versus private access to each dose

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.

Do doses differ between NHS and private?

The licensed dose ladder is the same either way: start at 2.5mg, step up at a minimum of four-week intervals, maximum 15mg.¹ What differs is who prescribes, how quickly you can start and how you pay. The NHS charge for a prescription in England is £9.90 per item where it applies, but whether you qualify for NHS-supplied Mounjaro depends on the phased NHS criteria, so speak to your GP about where you stand. The NHS also publishes its own guide to the medicine.⁵

How ordering with us works

Ordering has four stages and each is described as it actually happens:

• 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 by DPD in discreet, temperature-controlled packaging.

Start with the free consultation, or look at the full range on our weight loss treatments page. We are a GPhC-registered pharmacy (registration 9012878), which you can confirm on the GPhC register.¹²

Avoiding counterfeit pens

Buy Mounjaro only from a registered pharmacy that supplies through a prescription after a consultation. Anyone offering to supply without a consultation or prescription is a red flag, as are pens with no pharmacy label. The MHRA publishes counterfeit medicine alerts, and you can report suspected problems or side effects through the Yellow Card scheme.⁷

Support after your first dose

Aftercare includes ongoing monthly reviews, dose titration and follow-up by the prescribing team, plus side-effect support. GLPTrackr, our free companion app for iOS and Android, lets you track your journey, including which dose you are on and when you injected.