Can I Stay on 5mg Mounjaro for Weight Loss? (October 2026)

01 · The short answer

Can you stay on 5mg Mounjaro and keep losing weight?

Yes. The licensed dose ladder says it plainly: 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.¹¹¹ Nothing in the licence forces you to climb to 15mg.

Everyone starts on 2.5mg, but that starting dose is about letting your body adjust, not about weight loss itself.¹ Most measurable progress builds from 5mg onward, month by month.¹ So 5mg is the first dose where the medicine is expected to do real work, and for plenty of people it is also the last dose they need.

The real question is not 'is 5mg allowed?' but 'is 5mg still working for me?'. If your weight is trending down, your appetite is quieter and you are comfortable, your prescriber can confirm whether staying on 5mg suits you. If you want to understand how long people typically hold this dose, our guide on how long to stay on 5mg goes into the timing in more detail.

02 · Decide

How to tell whether 5mg is enough for you

Judge 5mg by the trend over weeks and months, not by a single weigh-in. Early loss includes water weight, so one low or high reading tells you very little.¹ It is a guide for discussion with your prescriber, not a prescription.

For a closer look at progress while you hold this dose, see our page on still losing weight on 5mg.

03 · Next step

What to do next

If you are already on treatment and unsure, the useful move is a review, not a self-made dose change. Note your weight trend, appetite and side effects over recent weeks and take them to your prescriber. If you are just starting out, our weight loss clinic explains how treatment works from the first consultation, and you can see current pen options on the Mounjaro pen page.

04 · What the trial shows at 5mg

What the trial shows at 5mg

Trial data show 5mg produces substantial 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.²

Reading those figures honestly matters. Higher doses averaged more loss in the trial, so 5mg is not identical to 15mg in effect. But the 5mg result is still large, and the difference has to be weighed against tolerability, how you feel day to day and what you personally need. Trial averages do not predict your own result.

Another figure is useful for anyone asking whether 5mg is 'worth it'. 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 Trial averages do not predict your own result, so your prescriber reviews your own response.

Treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.² If you want to see how loss tends to unfold over time, our page on the typical weight loss curve shows why progress is rarely a straight line.

05 · How Mounjaro works

How Mounjaro works for weight loss

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.¹

Tirzepatide is the first treatment of its kind to activate 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 In practice, most people feel fuller sooner and less hungry between meals, which supports a reduced-calorie diet.¹

That mechanism explains why 5mg can be enough. Your prescriber will guide the right dose for you, depending on how you respond and tolerate it. If you find you are satisfied with smaller portions and cravings are manageable, the dose is already doing what it should. If you still feel constantly hungry, that is useful information for your prescriber.

This dual action is what distinguishes Mounjaro from single-action GLP-1 medicines such as semaglutide (Wegovy/Ozempic).¹ It also means the dose ladder and review points are specific to tirzepatide, so advice written for another medicine does not transfer directly.

06 · Review points and slow response

Review points if progress is slow

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.¹

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.¹⁴ Note the wording: the highest tolerated dose. If 5mg is where you tolerate treatment best, that is the dose the review is judged against, and a slow start does not by itself mean something has failed.

If you are only a short way in, our page on staying on 5mg for a couple of months may help. Patience is part of the treatment, but so is honest feedback to your prescriber.

07 · What happens if you stop

What happens when you stop taking Mounjaro

If you stop, the medicine leaves your body gradually, not instantly. 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

Stopping should always be planned with your prescriber. In SURMOUNT-4, people who stopped tirzepatide after 36 weeks regained on average 14% of body weight over the following year, while those who continued treatment lost a further 5.5% on average.

If your reason for stopping is that 5mg feels like too much, remember the alternative: staying on treatment at a dose your prescriber agrees is right, or stepping down within the licence, rather than stopping suddenly.

08 · Day-to-day routine at 5mg

Keeping a steady routine on 5mg

Consistency is what keeps a maintenance dose working. Mounjaro is injected under the skin once a week, on the same day each week, at any time of day, with or without food.¹³ There is no 'best' time of day: it works the same morning or evening. What matters is the same day each week.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.¹³

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.¹³ You can change your weekly injection day if needed, as long as there are at least 3 days between two doses.¹³

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. Do not use a pen that has been above 30°C or has been frozen.¹³ For more on this strength, see our overview of 5mg weight loss injections.

09 · 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

10 · Cost and NHS access

What staying on 5mg costs, and NHS access

A 5mg pen costs £218.99 per month at the standard price, which works out at about £54.75 per week. A new customer's first order is £40 less with code FIRST40, and an automatic £25 reorder discount applies to every future order (code DOSE25). A first year (13 pens) costs £2,711.88 at standard prices if you stay on 5mg after your 2.5mg starting pen, before those discounts. Across the UK pharmacies we track, Mounjaro pens ranged from £143.96 to £339.00 per month at all doses when checked 10 October 2026.

Mounjaro is available on the NHS, but access is being phased in over several years.⁵⁶ NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition, and the primary-care rollout began with the highest-need groups first. Full rollout is expected to take years, which is why many people who meet the licensed criteria choose regulated private treatment rather than waiting.

Private treatment with us starts with a free online consultation reviewed by a GPhC-registered prescriber, and ongoing monthly reviews are included. We supply genuine KwikPens through official LillyDirect supply, so you are not guessing where your pen has come from. Repeat orders re-check suitability, with no auto-shipping.