Mounjaro 10mg Pen UK: Price, Doses and How It Works (October 2026)

01

What 10mg costs over a year

Nobody starts on 10mg. Everyone begins on 2.5mg and steps up, so the true cost is the route to 10mg plus the months you stay there. These costs are at standard prices, before discounts. A new customer's first order is £40 less, and every later order is £25 less.

A first year costs £2,399.88 if you settle at 5mg, up to £3,279.88 at 15mg. If 10mg is your maintenance dose, the monthly price of £274.99 is the number to plan around. Many people settle at 5mg, 10mg or 15mg, and higher is not automatically better.¹

02

What is included and how ordering works

The price covers a genuine KwikPen supplied through official LillyDirect supply, direct from Eli Lilly's UK distribution. Needles, a sharps bin and injection guidance come with every order. Delivery is free, next-day and tracked, in discreet temperature-controlled packaging. Saturday delivery costs £14.99. Monthly clinical reviews and side-effect support from our prescribing team are included, and repeat orders re-check suitability. Nothing ships automatically and there is no subscription. You can pay by Visa or Mastercard, or use Klarna and pay-monthly options. All six doses are in stock.

Ordering takes three steps:

• Free online consultation. A short health questionnaire with no charge and no obligation. Start your free consultation.
• Prescriber review. A GPhC-registered prescriber reviews your answers. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.
• Dispatch and delivery. Our registered pharmacy dispenses your pen, with same-day dispatch when ordered by 3pm and free next-day delivery.

03

Buying safely: counterfeit pens and unregulated sellers

Buy Mounjaro only from a pharmacy you can find on the GPhC register. Ours is registration 9012878, which you can check on the GPhC register.¹² The MHRA publishes counterfeit medicine alerts, and a seller offering to supply without a consultation or prescription is a clear warning sign.⁷ A very low price from an unregulated seller is a reason for more caution, not less. If you notice a side effect from any pen, you can report it through the Yellow Card scheme.¹⁹

Related guides: Mounjaro Injection 2.5 mg Price and How many clicks in a 10 mg mounjaro pen and Cost of 10mg mounjaro pen.

04 · What the 10mg pen contains

What a Mounjaro 10mg KwikPen contains

A Mounjaro 10mg KwikPen is a pre-filled multi-dose pen containing four weekly doses of 10mg tirzepatide. 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. The KwikPen comes in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹

A Mounjaro 10mg pen delivers four 10mg injections, one per week. Each pen therefore lasts four weeks if you take it as prescribed.¹³

The strength printed on the pen is the dose of each weekly injection, not the total in the pen. When you read the label on a pen, look for the dose it delivers each week. The number shown in the dose window on the day of injection should match the dose your prescriber has told you to take.

You do not need to measure, draw up or mix anything. The pen is set by turning the dose knob until the dose indicator shows the correct dose in the window. Follow the pen's instructions for the injection itself.

The strength, not the appearance, is what matters, so always check the label against your prescription.

The 10mg pen is only one rung on the ladder. A prescriber chooses it for you after assessing your response and tolerance at lower doses, and not because it is a 'stronger' option to aim for. Higher is not automatically better, and many people do well on 5mg or 15mg instead.

Finally, remember the product is prescription-only. It is supplied only after an online consultation reviewed by a GPhC-registered prescriber, and it is used alongside a reduced-calorie diet and increased physical activity. Individual results vary.

05 · How tirzepatide works

How tirzepatide works

Tirzepatide activates two natural gut-hormone receptors at once, GIP and GLP-1. It is the first treatment of its kind to do so. Together these actions help regulate appetite, slow how quickly the stomach empties, and improve the way the body responds to insulin.¹

In practice, most people feel fuller sooner and less hungry between meals. That supports a reduced-calorie diet, which is why the medicine is licensed for use alongside diet and activity rather than in place of them. The dual action distinguishes Mounjaro from single-action GLP-1 medicines such as semaglutide (Wegovy and Ozempic).¹

The strength of the pen does not change what the medicine does. A 10mg dose works through the same two receptors as a 2.5mg dose. The ladder exists so that your body can adjust gradually, and so your prescriber can find the dose you respond to and tolerate.

Tirzepatide has a half-life of about five days. 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 It is a practical point if you are thinking about stopping or changing dose: the medicine does not vanish the day after your last injection.

Judge a dose across several weeks rather than the first few days after each injection, when the early effects are most noticeable. Your prescriber reviews your response at each step, and our team includes monthly clinical reviews with every order.

If anything about how you feel changes after starting or stepping up a dose, tell your prescriber. Side effects can also be reported through the Yellow Card scheme.¹⁹

06 · Where 10mg sits on the ladder

Where 10mg sits on the dose ladder

Mounjaro 10mg is the fourth of six steps, and nobody starts on it. Everyone begins on 2.5mg once a week. This starting dose is about letting your body adjust, not about weight loss itself.¹

After at least 4 weeks the dose increases to 5mg. It 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 Those are minimum intervals, and your prescriber may hold you at a dose for longer.

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

These are standard prices before discounts. A new customer's first order is £40 less at any dose, and every later order is £25 less.

Moving to 10mg is a prescriber decision based on how you have responded and tolerated the previous dose. You should not step up early, and you should not skip steps because you have heard others do so. If you are switching to us from another provider already on 10mg, the prescriber will review your current dose and medical history before approving it, and the first-order discount applies at 10mg too.

07 · Results on 10mg

What results to expect on 10mg

In the SURMOUNT-1 trial of 2,539 adults, people taking tirzepatide 10mg alongside diet and exercise lost on average 19.5% of their body weight over 72 weeks. For comparison, people on 5mg lost 15% and people on 15mg lost 20.9%, against 3.1% with lifestyle changes alone.² These are trial averages, individual results vary, and treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.

At 72 weeks, 89% of participants on 10mg had lost at least 5% of their body weight. Half of participants on 10mg lost at least 20% of their body weight.² As a worked example only, for someone starting at 100 kg, 19.5% is about 19.5 kg. That is arithmetic on a trial average, and trial averages do not predict your own result.

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.¹ Trials measured results at 72 weeks, so think in months, not days, and judge progress by trend, not individual weigh-ins.

Some people notice appetite change and early loss in week one, while others feel little until a higher dose. Both are normal. Early loss includes water weight, which is another reason 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.¹

Your prescriber reviews your response. 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

A stated trial average is evidence of what is possible on average, not a promise of what you will lose.

The practical takeaway is simple. Ten milligrams is a dose with substantial trial evidence behind it, and it is a common landing point. But it is only right if you have reached it by gradual steps and tolerate it well, and your prescriber, not the trial table, decides whether it is the right maintenance dose for you.

08 · Injecting and missed doses

Injecting, missed doses and changing day

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 There is no best time of day. It works the same morning or evening, and what matters is the same day each week. Many people choose a weekend morning so early side effects fall on days off.

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. Each KwikPen contains four weekly doses, so a 10mg pen covers four consecutive weeks.¹³ Follow the pen's instructions for the injection itself.

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 you need to change your injection day, you can, as long as at least 3 days (72 hours) have passed since your last dose.¹ This is useful when work or travel changes your week. Make the change once, move to the new day, and then keep it there.

The licensed schedule is once a week. If something is making weekly injections difficult, such as side effects, talk to your prescriber.

Side effects after injecting are usually mild at first. Mild nausea, altered appetite and tiredness in the first days after each injection are the commonest early effects and usually settle. If they do not, or if you notice something new, contact your prescriber and consider reporting it through the Yellow Card scheme.¹⁹ Our team offers side-effect support and ongoing monthly reviews, and you can reach us Monday–Friday 9am–5pm.

09 · Storage and travel

Storing and travelling with your pen

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 not above 30°C for up to 30 days, after which it should be discarded.¹ Keep the pen cap on to protect it from light, and never use a pen that has been frozen.

The 30-day limit answers a frequent question: why can you not use a pen after 30 days? Outside the tested window, sterility and potency are no longer assured, so the pen should be discarded. A 10mg pen holds four weekly doses, which is four weeks, so a pen used on schedule is finished inside that limit. Using a single pen for eight weeks is therefore not a licensed or sensible way to use it.

For unopened pens, the position is simpler: store them in the fridge until first use, and they 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. The patient information leaflet and our team are the right sources.¹³

Travelling: you can fly with Mounjaro. 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. 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

When your order arrives, it comes in discreet, temperature-controlled packaging by free next-day tracked delivery. Move the pen to the fridge promptly unless you are starting it that day. Do not leave a parcel on a doorstep or in a car, and use our delivery tracking to be at home when it arrives.

A simple routine keeps things safe. Put the pen you are not using in the fridge, keep the cap on the pen in use, note the date you first used the pen, and discard it when the 30 days (not above 30°C) are up even if the window suggests medicine remains. Dispose of used needles in the sharps bin provided with your order. If you ever doubt a pen's condition, do not inject. Ask the pharmacy first.

10 · 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

11 · Eligibility and NHS access

Who can use it, and NHS versus private

Mounjaro is licensed for weight management in adults with a BMI of 30 or above, or a BMI between 27 and 30 with at least one weight-related condition. Examples include high blood pressure, high cholesterol, obstructive sleep apnoea, cardiovascular disease, prediabetes or type 2 diabetes.¹ It must be used alongside a reduced-calorie diet and increased physical activity. A prescriber will assess your BMI, medical history and current medicines before deciding whether it is suitable for you. You should not take Mounjaro if you are allergic to tirzepatide or any of its ingredients, and it should not be used during pregnancy or while trying to conceive. Mounjaro must not be used during pregnancy, and it 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. 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.

That assessment is why the consultation matters. It is free, takes the form of a short health questionnaire, and carries no obligation. A GPhC-registered prescriber reviews it, 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.

On the NHS, Mounjaro is available, 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 NHS has its own tirzepatide guide for patients.⁵

Private and NHS routes are not the same in how you start. On the NHS you begin with your GP or a specialist service and your eligibility is decided locally within the phased rollout. Privately, the licensed criteria apply and a prescriber decides after your consultation. Either way, you begin on 2.5mg, not 10mg.

If you are already on 10mg from another provider and want to move, tell us in the consultation. The prescriber will review your current dose and history, and the new-customer discount applies to a first order at any dose. Repeat orders re-check suitability each time, and nothing is auto-shipped.

Our service is a full UK online pharmacy, and over 100,000 customers have been supported by us on their weight loss journey. That figure describes customers served, not results. Your prescriber can talk you through other options.