Are There Different Strengths of Mounjaro? (October 2026)

01 · The answer

Yes, there are six strengths of Mounjaro

Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly. It comes as a pre-filled multi-dose pen (KwikPen) in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹ In the UK it is licensed for weight management in adults and for type 2 diabetes.¹

Every strength is the same medicine in the same type of pen. Only the amount of tirzepatide per weekly dose changes.

Your prescribing team decides when to move between strengths, based on how you are tolerating treatment and responding. You can read a fuller strength-by-strength breakdown in our guide to Mounjaro strengths explained.

02 · The reason

Why are there different strengths of Mounjaro?

The strengths exist so that treatment can begin gently and be adjusted to the individual. 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 the way the body responds to insulin.¹ Starting at the lowest strength gives your body time to get used to those effects.

Nobody needs to use every strength. The ladder is a set of steps, not a mandatory route to the top. Some people stay on a middle strength because it works for them, and your prescriber reviews that choice with you regularly.

When you are ready to see current options, the Mounjaro pen page shows live prices for each strength and starts the free consultation.

03 · Your decision

What this means for you

If you are new to Mounjaro, the question is not which strength to buy, because you begin at 2.5mg. The real decisions come later: how quickly to step up, and which strength to settle on.

If you are switching from another provider, you may already be on a higher strength. A reviewed consultation lets the prescriber confirm the right strength for you rather than assuming you restart. Our weight loss clinic page explains how treatment and follow-up are organised.

04 · Starting dose and titration

How the strengths work as a ladder

Treatment begins at 2.5mg, and the dose is then increased in steps rather than all at once. Dose changes are made after at least 4 weeks on each dose, depending on how you respond and tolerate it, and only when the prescribing team is happy with how you are doing.¹

That is why a gradual rise is built into the way Mounjaro is supplied. If the strengths did not exist, there would be no way to step up in measured increments. If you step up after 4 weeks on each of 2.5mg, 5mg, 7.5mg and 10mg, the standard price of your first four pens adds up to £959.96 before discounts. A new customer's first order is £40 less with code FIRST40, and every later order is £25 less.

The ladder is also the reason your prescriber asks how you are feeling at each step. If you find a strength hard to tolerate, tell the team. Do not decide for yourself to skip a step or to move up faster than planned. The patient information leaflet explains how to use the pen and what to do if you have problems.¹³

05 · Do higher strengths mean more weight loss?

Do you lose more weight on higher strengths of Mounjaro?

On average in the main trial, yes: the higher the strength, the greater the average weight loss. 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.² Trial averages do not predict your own result.

At 72 weeks, 85% of participants on 5mg, 89% on 10mg and 91% on 15mg had lost at least 5% of their body weight.² Half of participants on 10mg and 57% on 15mg lost at least 20% of their body weight.²

As a worked example, for someone starting at 100 kg, 20.9% is about 21 kg. That is an average, not a target, and it is no promise for any individual.

The practical lesson is that a higher strength is a tool, not a goal. Your prescriber is the person to judge the right strength for you, based on your response and tolerance.

06 · Which strength is best?

Which strength of Mounjaro suits you?

No single strength is right for everyone; the right one is the strength that suits you at the time. It depends on how you respond, what side effects you have, and your health conditions. That is a decision for you and a GPhC-registered prescriber together, not something to work out from a chart.

Think of it in stages. At the start, you use the lowest strength, because the aim is to let your body adjust. During step-up, the strength is the one your prescriber has chosen for that month. Once you have settled, many people stay on a strength that keeps them responding well with side effects they can live with.

It is also worth knowing that NICE's practical prescribing guide covers how tirzepatide is used for weight management in NHS settings.⁴ Private treatment follows the same product licence, and the strengths are identical.¹

Each strength has its own standard price: £169.99 for 2.5mg, £218.99 for 5mg, £279.99 for 7.5mg, £290.99 for 10mg, £319.99 for 12.5mg and £329.99 for 15mg, all per month, checked 10 October 2026. Every order after the first is £25 off those standard prices.

07 · 2.5mg compared with 5mg

What is the difference between Mounjaro 2.5mg and 5mg?

The 5mg pen delivers a higher weekly dose than the 2.5mg pen. Both are the same medicine in the same type of KwikPen. The 2.5mg pen is the starting strength, and 5mg is the first step up from it.¹

Because the starting strength is lower, it is used to introduce the medicine gently. Moving to 5mg is a decision made after you have had time on the starter pen.

If you are currently on 2.5mg and wondering whether to ask for 5mg sooner, raise it at your review. Do not try to reach it yourself.

08 · Combining or splitting pens

Can I use two doses of 2.5mg to make 5mg?

No. Each pen is designed to deliver the dose printed on it, and combining or splitting doses to reach another strength is not something we support. It is outside the licensed use of the medicine.¹

There are practical reasons as well. Extra injections would mean using up a pen faster than intended, and you could not be sure of the amount you had taken. If a strength feels too low, speak to your prescriber, who can move you to the right pen through a proper review.

The same goes for taking an extra dose because you missed one or feel the effect is weak. Follow the patient information leaflet and ask the prescribing team when you are unsure.¹³

09 · Is every pen the same?

Is all Mounjaro the same strength?

No. The pens are made in six different strengths, so a pen you are given may be quite different from the one a friend uses. Always check the strength printed on your pen and on your dispensing label before each injection.

Tirzepatide is the active ingredient and Mounjaro is the brand name, so asking about different strengths of tirzepatide is the same question. In the UK, the licensed pen range we supply runs from 2.5mg to 15mg.¹

Storage is the same for every strength. Keep unopened pens in the fridge at 2–8°C until first use, and they keep until the printed expiry date. Once in use, a KwikPen 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. Do not use a pen that has been above 30°C or frozen.¹¹³ If you are unsure about a pen, check the leaflet or contact us.

Do not confuse strengths with types of product. If you are wondering whether there are other versions, our page on different types of Mounjaro covers that separately.

10 · Common questions about routine

Timing, food, sleep and how soon it works

These questions come up often, though the answers do not depend on the strength you use. There is no "best" time of day: Mounjaro works the same morning or evening, with or without food, and what matters is the same day each week.¹³

Most people feel fuller sooner and less hungry between meals,¹ but the timing differs between people. Do not expect the full effect from the starter pen, which is there to help your body adjust.

Treatment is used alongside a reduced-calorie diet and increased physical activity, and no food is banned; your prescriber or pharmacist can advise on foods that disagree with you.

If you notice a new or lasting symptom, tell your prescriber and report it through the Yellow Card scheme.¹⁹

11 · Supply, NHS and cost

Getting the strength you need

We supply Mounjaro through official LillyDirect supply, meaning direct from Eli Lilly's UK distribution, and all six strengths are in stock. If you want background on availability, see our page on whether there is a supply issue with Mounjaro.

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.

Eli Lilly raised the UK list price of Mounjaro in September 2025, so it is worth comparing live prices.¹⁰ Across the UK pharmacies we track, the cheapest and dearest Mounjaro pens ranged from £143.96 to £339.00 per month as of 10 October 2026.

If you are curious about other weight-loss injections, our guides to how many weight loss injections exist and the different types of weight loss injections compare the options. And if you have seen products marketed as natural alternatives, read whether there is a natural Mounjaro before spending money on them.

12 · Stopping or changing strength

What happens if you change or stop

Changing strength is a prescriber decision, up or down. If you move to a lower strength, that is a normal part of managing treatment and not a failure.

If you stop altogether, 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. There is no way to speed this up, and nothing needs doing while it clears.¹

Before restarting after a break, speak to the prescribing team rather than assuming you can resume at your old strength. Repeat orders re-check suitability, and we do not auto-ship.

Mounjaro is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber. It is used alongside a reduced-calorie diet and increased physical activity. Individual results vary. This page is information, not a substitute for medical advice. We are registered with the GPhC under number 9012878, and orders are dispensed by our registered pharmacy.

13 · 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