What's the Dosage of Mounjaro? UK Dose Ladder (October 2026)

01 · The core answer

The Mounjaro dose ladder, strength by strength

Everyone starts Mounjaro 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, 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.¹

For a longer walk-through of each stage, see our guide to the full set of Mounjaro doses.

Each step is a minimum, not a target. Your prescriber can keep you on one strength for longer if side effects are the concern or the current dose is working well. Our explainer on Mounjaro dosage increments covers how those gaps work in practice.

02 · What you need to decide

Which dose will I end up on?

Your maintenance dose depends on your response and tolerance, not on a fixed schedule. 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 You do not have to reach 15mg.

If you are comparing with the other well-known weekly injection, see how tirzepatide and Wegovy dosing differ.

Ready to start? You can begin with a free consultation for the Mounjaro pen. The 2.5mg starter pen has a standard price of £169.99, and your first order with code FIRST40 costs £129.99. If you step up after 4 weeks on each dose, your first four pens (2.5mg to 10mg) cost £959.96 at standard prices. A new customer's first order is £40 less, and every later order is £25 less.

03 · How each dose is injected

How each weekly dose is injected

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: Mounjaro works the same morning or evening. What matters is the same day each week, so pick a day and time you will remember. Many people choose a weekend morning so early side effects fall on days off.¹³

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.¹

The pen is set by turning the dose knob until the dose indicator shows the correct dose in the window. Each KwikPen contains four weekly doses. Needles, a sharps bin and injection guidance are included with every order.

04 · Missed doses and day changes

What to do if you miss a dose or want to change day

The missed-dose rule is simple and depends on how long ago the dose was due. 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

You can also move your weekly injection day 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

If you have missed several doses in a row, do not guess at the strength to restart on. Contact the prescribing team through your account so they can advise on the right dose for you.

05 · 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 — useful for short trips — after which it should be discarded. Keep the pen cap on to protect it from light, and never use a pen that has been frozen.¹

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.¹³

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 rather than relying on a remembered day limit — figures circulating online often come from other countries' labels.¹³ Orders arrive by free next-day tracked delivery in temperature-controlled packaging.

06 · Dose, pace and results

How dose relates to results

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 Experiences differ widely in the first weeks: some people notice appetite change and early loss in week one, others feel little until a higher dose, and both are normal. Early loss includes water weight, so the trend over weeks matters more than any single weigh-in.

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 — individual results vary, and treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.²

Treatment response is reviewed by your prescriber: 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.⁴ A higher dose is therefore never the goal in itself. The goal is the dose that works for you with side effects you can manage.

07 · Microdosing and off-label use

Why we don't support microdosing or altered doses

Altering doses outside the licence means unknown dosing accuracy and no safety data.

If the current dose feels too strong, speak to the prescribing team rather than adjusting it yourself. Staying on a lower strength for longer is a legitimate, licensed option. Our page on the standard Mounjaro dosing pattern shows what the usual route looks like.

08 · Dose questions about the NHS

Is the dose different on the NHS?

The licensed dose ladder is the same whether you are treated on the NHS or privately. 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.

Privately, Mounjaro 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. Our weight loss clinic explains the full pathway. For a second look at strengths in plain terms, see Mounjaro dosage amounts, or how the dose steps work.

09 · How long a dose stays active

How long a dose stays in your system

Tirzepatide has a half-life of about five days, so 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

The licensed dose ladder steps up gradually, with at least 4 weeks on each dose, depending on how you respond. The medicine works by activating two natural gut-hormone receptors at once, GIP and GLP-1, which helps regulate appetite and slows how quickly the stomach empties. In practice, most people feel fuller sooner and less hungry between meals.¹

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