What Is the Best Dose of Mounjaro to Lose Weight? (October 2026)

01 · The short answer

What is the best dose of Mounjaro for weight loss?

The best dose is the lowest one that produces steady, sustainable loss while side effects stay manageable. That differs from person to person, which is why the licence gives a ladder rather than a single target.

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) up 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, and your prescriber will guide the right pace.

02 · Your decision

Which decision are you actually facing?

If you have not started, the decision is simple: you begin on 2.5mg whatever your goal. Our guide to the best starting dose covers why. Nobody is offered a higher first dose to speed things up, and anyone offering to skip the starting dose is not following the licence.

If you are already on treatment, the decision is whether to stay put or step up. Staying is reasonable when your weight is trending down and side effects are tolerable. Stepping up is worth discussing when progress has genuinely stalled, your food intake is honestly under review and you are not yet at the maximum. Our page on the best dosage for Mounjaro goes deeper on that reasoning, and the UK dose guide for weight loss offers a second view.

Response is also checked formally. 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 is a safety net, not a race.

03 · Next step

Where to go from here

When you are ready to start or continue, our weight loss clinic explains the process. Treatment is a prescription-only medicine supplied after a free online consultation reviewed by a GPhC-registered prescriber, and it works alongside a reduced-calorie diet and increased physical activity. Individual results vary.

04 · The dose ladder

The Mounjaro dose ladder explained

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 Each strength is a rung on the ladder, and you only climb as far as you need to.

The first rung, 2.5mg, is a tolerability dose. The licence says this starting dose is about letting your body adjust, not about weight loss itself.¹ Some people still notice a change in appetite, but you should not judge the medicine by those first weeks. The licence sets a minimum of 4 weeks on each dose, and it is a minimum rather than a target. Plenty of people stay on a dose for longer because it is working or because they want side effects to settle before stepping up.

From there the steps are 7.5mg, 10mg and 12.5mg, finishing at 15mg.

Many people settle at a maintenance dose of 5mg, 10mg or 15mg, and higher is not automatically better.¹ Think of the dose as a dial you adjust with your prescriber, not a score. A person who loses steadily on 5mg has found their best dose. A person who needs 15mg to see progress has found theirs. Neither has done anything wrong.

The medicine is injected under the skin, and each pen contains four weekly doses.

If you want the practical side of keeping on track once you have a dose, our guides on the best way to lose weight on Mounjaro and how best to lose weight on it cover habits that sit alongside any dose. Everything here is information, not a substitute for advice from your prescriber.

05 · What trials show

What the trial results show at each dose

The largest dose-by-dose evidence comes from SURMOUNT-1. In the SURMOUNT-1 trial of 2,539 adults, people 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. Treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.

The same trial reported how many people reached key 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% of their body weight.²

What do these figures mean for choosing a dose? First, the average rose with dose, so a higher dose can mean more loss on average. Second, these numbers describe groups. Your own result may sit well above or below the average, and trial averages do not predict your own result.

It also helps to be clear about the timescale. The trial measured outcomes at 72 weeks. That is well over a year of treatment, so anyone expecting the headline figures after a few months will be disappointed. Progress builds month by month, and the full averages are measured at the end of the trial rather than at three months.

It is tempting to read the 15mg figure as a promise and aim straight for the top rung. Resist that. The licence allows the maximum, but it does not require it, and higher is not automatically better.

Do not compare these numbers with trials of other medicines as if they were head to head. Each trial had its own design and population. For choosing a Mounjaro dose, the SURMOUNT-1 pattern is simply a useful guide: more dose, on average more effect, never a certainty.

06 · Realistic pace

How fast should you expect to lose weight?

Weight loss on Mounjaro is gradual by design. 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 — think in months, not days, and judge progress by trend, not individual weigh-ins.¹ That pace is exactly why chasing the highest dose early is rarely sensible.

The first weeks deserve their own mention. The 2.5mg starting weeks are about adjustment, and experiences differ widely: some people notice appetite change and early loss in week one, others feel little until a higher dose — both are normal.¹ Early loss includes water weight, so the trend over weeks matters more than any single weigh-in. Mild nausea, altered appetite and tiredness in the first days after each injection are the commonest early effects and usually settle.

By around three months, most people are still on the lower rungs of the dose ladder, so trial-average losses at this stage are modest compared with the headline figures. A sensible 3-month expectation on a standard titration is mid single digits as a percentage of body weight, with wide individual variation.² Slower early progress does not predict failure, because the dose you respond to may still be ahead of you.

This matters for dose choice in a practical way. If you judge a dose after only a couple of weeks, you may step up before it has had a chance to work. If you give each dose a fair run, you often learn that a lower dose is enough.

It is also worth deciding in advance how you will measure progress. Weigh yourself at a consistent time and look at the trend across several weeks. Notice other changes too: how full you feel, how your clothes fit, how often you snack. Our page on struggling to lose weight on Mounjaro helps if the scales are not moving, and our article on losing weight on the lowest dose addresses a very common question about the starting phase.

Treatment response is reviewed by your prescriber, so you are not left guessing. The review point is anchored to time on the highest tolerated dose, which again reinforces that the ladder is a slow climb rather than a sprint.

07 · When to step up

When does it make sense to go up a dose?

Stepping up makes sense when you have spent a fair time on your current dose, are tolerating it, and progress has stalled despite honest effort. The licence sets a minimum of 4 weeks on each dose, but a minimum is not an instruction to move on the moment you can.¹ Your prescriber looks at how you are responding and how you are feeling before agreeing a step.

Weight loss on Mounjaro is not linear. Plateaus of a few weeks are normal and expected as the body adapts to a lower weight.¹ Within the licence, the responses are: review food intake honestly (portions drift back up), protect protein and activity, check the basics (sleep, 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.

That order matters. Many plateaus are fixed by habits rather than milligrams, so the dose is the last lever, not the first. If portions have crept up or alcohol has become regular, a higher dose may simply be asked to cover for those habits. Our guide on what to eat on Mounjaro is a good place to reset.

Equally, there are good reasons not to step up. If you are losing steadily, there is no need to move. If side effects such as nausea are still bothersome, speak to your clinical team before stepping up.

Remember the safety net too. 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 This conversation is built around you, and it may lead to a longer hold, a step up, or a different plan altogether.

Finally, stepping up is a decision for you and your prescriber together. Our service 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 is auto-shipped, so a dose change is always a considered decision rather than a default.

08 · Higher is not better

Why a higher dose is not automatically better

A higher dose gives a higher trial average, but it is not always the right choice for the individual. 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.¹ The aim is a dose that works for you and that you can tolerate.

Side effects are the main reason to hold or step down. Mild nausea, altered appetite and tiredness in the first days after each injection are the commonest early effects and usually settle.¹ Side effects are most likely when moving up a dose, so a step up is sometimes followed by a rougher few days. You can also read the patient information leaflet for the full list of effects and what to do about them.¹³ If you notice a new symptom, report it to your prescriber and consider reporting it through the Yellow Card scheme.¹⁹

There is also a practical argument. If you reach your goal on a middle dose, you are on less medicine, and a later review can focus on maintaining progress rather than pushing further. Reaching the maximum should be a response to need, not an ambition.

Beyond the scales, trial participants saw other benefits. 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 show why prescribers think of weight management as health management rather than appearance. That broader view also supports choosing a dose you can sustain, because benefits depend on staying on a workable plan.

What about splitting a pen to make it last? The answer is firmly no. Altering doses outside the licence means unknown dosing accuracy and no safety data.

09 · Injecting consistently

Injecting consistently so your dose works

Your dose can only do its job if you take it regularly. Mounjaro is injected under the skin (subcutaneously) once a week, on the same day each week, at any time of day, with or without food.¹ Licensed injection sites are the stomach area (at least 5cm from the belly button), the front of the thigh, or the back of the upper arm if someone else gives the injection. Rotate the site with each dose.

There is no best time of day. Mounjaro works the same morning or evening, with or without food. What matters is the same day each week. Pick a day and time you will remember, and many people choose a weekend morning so early side effects fall on days off.¹

The pen is simple but precise. The Mounjaro KwikPen is set by turning the dose knob until the dose indicator shows the correct dose in the window. Follow the pen's instructions and the patient leaflet each time.¹³

Life gets in the way, so know the missed-dose rule. 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

If your routine changes, 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 Moving the day sensibly is far better than letting doses drift or doubling up.

Why does this belong on a page about the best dose? Because the dose that looks like it is failing is sometimes the dose that was taken irregularly. Before concluding you need to step up, check that injections have been regular, correctly dialled and rotated. Needles, a sharps bin and injection guidance are included with every order, so you are not left working it out alone, and our support team is available Monday to Friday if a question comes up.

10 · Storage and travel

Storing and travelling with your pen

Correct storage protects the dose you have chosen. Keep Mounjaro pens in a fridge at 2–8°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, and must then be thrown away. Keep the pen cap on to protect it from light, and never use a pen that has been frozen.¹

Unopened pens should be kept 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.

Travel is manageable. You can fly with Mounjaro. Carry pens in hand luggage (hold luggage can fall below freezing), ideally in a cool bag with the prescription label or a copy of your prescription. In-use pens tolerate up to 30 days not above 30°C, so most holidays need no special arrangements; for hot climates use an insulated pouch. Check destination rules for travelling with prescription injectables before you fly.¹

Why mention this on a dose page? Because a step up often coincides with a holiday or a change of routine, and a pen that has been frozen or overheated cannot be trusted to deliver the dose you expect. If a pen has been stored badly, do not use it and contact the pharmacy.

Plan your orders so you never run short abroad, and so each dose change lines up with the pens you actually hold. Because each pen contains four weekly doses, your supply and your titration step map neatly onto each other: a new strength normally means a new pen. Keeping a simple record, for example in our free GLPTrackr companion app, helps you see which dose you were on, when you moved up and how you felt.

Our pens come as genuine KwikPens through official LillyDirect supply, sourced directly from Eli Lilly's UK distribution, and are delivered free next-day in temperature-controlled packaging. Order by 3pm for same-day dispatch.

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 · NHS and private routes

NHS and private routes to your dose

Whichever route you use, the dose ladder is the same, because it comes from the licence. 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.

If you go private, it should be a regulated pharmacy. We are GPhC-registered (registration 9012878), and every order starts with a free online consultation, a short health questionnaire with no charge and no obligation. It is 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.

Ordering works in three steps. First, complete the free consultation. Second, the prescriber reviews it. Third, our registered pharmacy dispenses and dispatches, with free next-day tracked delivery. Saturday delivery is £14.99. The price shown is the price paid, with no hidden fees, and payment options include Visa, Mastercard, Klarna and pay-monthly plans, with no subscription lock-in.

On cost, the starter pen has a standard price of £169.99, while the 5mg pen is £218.99, the 10mg pen £290.99 and the 15mg pen £329.99. Pens are priced per four-week supply. New customers save £40 on their first order with code FIRST40, at any dose, and an automatic £25 reorder discount applies to every future order (code DOSE25). If you step up after 4 weeks on each dose, your first four pens (2.5mg to 10mg) cost £959.96 at standard prices, before discounts. A first year 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, at standard prices before discounts. Prices checked 10 October 2026, and all six doses are in stock.

You can see current live prices and start a consultation on the Mounjaro pen page.

Repeat orders re-check suitability, and aftercare includes monthly reviews and dose-titration follow-up, so your dose is reviewed rather than assumed. Tirzepatide has a half-life of about five days, so after a final dose it takes roughly four to five weeks to clear the system. Nothing needs doing while it clears, which is worth knowing if you ever pause treatment.¹