Dosing & Usage

Mounjaro Dosing Guide

Learn the standard Mounjaro dosing schedule in the UK, including starting dose, dose increases, maintenance doses, and common questions about moving up safely.

Whether you are about to start Mounjaro or trying to plan ahead for dose changes, this guide explains the licensed dosing schedule, why doses are stepped up gradually, and what to expect at each stage. LetsLoseWeight is an independent comparison site; we do not prescribe medication, and the right dose for you is a decision for your prescriber based on your individual circumstances.

The Mounjaro dose ladder

Mounjaro (tirzepatide) is given as a once-weekly subcutaneous injection. UK pre-filled pens are available at six dose strengths:

  • 2.5mg — starter dose only
  • 5mg — first maintenance dose
  • 7.5mg — intermediate dose
  • 10mg — second maintenance dose
  • 12.5mg — intermediate dose
  • 15mg — maximum maintenance dose

For weight management, the licensed approach is to start at 2.5mg once a week for 4 weeks, then step up by 2.5mg increments at intervals of at least 4 weeks until reaching a maintenance dose (Mounjaro SmPC, EMC). The dose is increased only if needed and tolerated — many patients settle on a lower maintenance dose than the maximum.

Why doses are stepped up gradually

The slow titration is not arbitrary. The most common side effects of tirzepatide are gastrointestinal — nausea, diarrhoea, constipation, and reduced appetite — and they are usually most pronounced when first starting or stepping up the dose. By increasing the dose in small increments and pausing for at least 4 weeks at each level, the body has time to adjust before facing more medication.

Skipping ahead in the schedule, or starting at a higher dose, increases the risk of severe side effects without any improvement in long-term weight loss. The regulated UK supply chain will not dispense doses outside the licensed schedule, and a prescriber will not normally agree to skip steps.

A typical Mounjaro dose schedule

This is the standard licensed approach. Individual prescribers may adjust pacing based on tolerability and clinical response.

Week Dose Notes
1–4 2.5mg weekly Starter dose. Allows the body to adjust. Not a maintenance dose.
5–8 5mg weekly First maintenance option. Some patients stay here long-term.
9–12 7.5mg weekly (if needed) Intermediate step on the way to 10mg.
13–16 10mg weekly Second maintenance option. Many patients settle here.
17–20 12.5mg weekly (if needed) Intermediate step on the way to 15mg.
21+ 15mg weekly (if needed) Maximum maintenance dose.

The decision to step up at each interval is taken by the prescriber based on weight progress, side-effect tolerance, and overall clinical picture. There is no requirement to reach 15mg — clinical effectiveness varies between people and many do well at 5mg or 10mg.

What "maintenance dose" means

A maintenance dose is the long-term dose at which a patient stays once they have completed titration. For Mounjaro, the licensed maintenance options are 5mg, 10mg and 15mg. The 7.5mg and 12.5mg pens are intermediate steps used during titration but can also be used as maintenance doses if a patient is doing well at that level.

The right maintenance dose is whichever one delivers a meaningful weight-loss outcome with manageable side effects. In the SURMOUNT-1 trial, average weight loss after 72 weeks was around 15% at 5mg, 19.5% at 10mg, and 20.9% at 15mg — improvements that are real but each step up brings diminishing returns (Jastreboff et al., NEJM 2022).

Missed doses

If you miss a dose, take it as soon as you remember within 4 days (96 hours) of the missed dose. After more than 4 days have passed, skip the missed dose entirely and inject the next one on your normal schedule. Don't double up.

If you miss two or more consecutive doses, contact your prescriber before the next injection — depending on how long the gap has been, your prescriber may want to drop you back a dose level to avoid a recurrence of side effects.

For more detail, see our missed dose guide.

Switching from Wegovy to Mounjaro

If you are switching from Wegovy (semaglutide) to Mounjaro (tirzepatide), the standard advice is to stop Wegovy and wait around 5 weeks before starting Mounjaro, then begin at the standard 2.5mg starter dose regardless of the dose you were on with Wegovy. The medicines act on different combinations of receptors and the doses do not equate.

For more detail, see our switching from Wegovy to Mounjaro guide.

How to take a Mounjaro injection

Mounjaro is given as a subcutaneous (just-under-the-skin) injection using a single-use pre-filled pen. Key practical points:

  • Inject once a week, on the same day where possible. Time of day doesn't matter, and the injection can be given with or without food.
  • Rotate injection sites. The licensed sites are the abdomen, the front of the thigh, and the back of the upper arm. Rotate within and between these sites to reduce skin reactions.
  • Storage. Unused pens should be kept refrigerated at 2°C–8°C. Once removed from the fridge, a pen can be kept at room temperature (below 30°C) for up to 21 days but must not be frozen.
  • Disposal. Used pens go into a sharps bin. Most UK pharmacies will provide a sharps bin and arrange disposal.

For step-by-step injection technique, see our how to inject guide and the manufacturer's instructions inside each pen pack.

What if a dose increase causes side effects?

It is normal for nausea, mild stomach upset, or reduced appetite to be more noticeable in the first few days after stepping up. They usually settle within 1–2 weeks. If side effects are persistent or severe, talk to your prescriber. Options include:

  • Pausing at the current dose for an additional 4 weeks before next step-up
  • Going back down a level to the previous tolerable dose
  • Stopping treatment if side effects don't settle

For practical strategies to reduce side effects, see our reduce side effects guide.

Frequently asked questions

Why is the 2.5mg dose called "starter only"?
At 2.5mg, the medicine is still building up to clinically meaningful exposure. The 4 weeks at 2.5mg is to let the body acclimatise to GIP/GLP-1 stimulation; clinically meaningful weight loss usually starts at 5mg or above.

Can I stay on a low dose to save money?
Some patients do well at 5mg long-term. Others find that weight loss plateaus and a higher dose is needed. The decision should be clinical, not financial — discuss with your prescriber.

What if I want to slow down between dose increases?
Slowing the titration to 6 or 8 weeks at each step (rather than 4) is often acceptable and may reduce side effects. Speeding it up below 4 weeks is not licensed and not recommended.

Will I need to stay on Mounjaro forever?
There is no fixed time limit on private treatment, and NHS treatment under TA1026 is not capped at 2 years (unlike NICE's earlier guidance for semaglutide). However, weight regain is common after stopping, so any decision to discontinue should be planned with your prescriber.

What is the highest dose of Mounjaro?
The maximum licensed dose for weight management is 15mg once weekly. There is no licensed indication for higher doses, and a regulated UK pharmacy will not dispense above 15mg.

Next steps

Sources

This guide is for general information only and is not a substitute for prescriber advice. The right dose for you is a clinical decision based on your individual circumstances.

Get weekly weight loss tips

Join our newsletter for provider updates, expert guidance, and exclusive offers — no spam.

Subscribe free
Back to Guides
Mounjaro Dosing Guide UK: Schedule and Titration | LetsLoseWeight