Mounjaro comes in six strengths. You do not pick one. The licence sets out a fixed starting dose and a fixed way of moving up, and your prescriber follows it. This page explains what each step is for, so you know what to expect before you start and why you will be asked to stay on a dose even when you feel ready to move on.
The schedule in one line
Start on 2.5mg once a week for four weeks. Move to 5mg. Stay there for at least four weeks. If you and your prescriber agree you need more, go up by 2.5mg at a time, never sooner than four weeks apart, up to a maximum of 15mg.
What each strength is for
| Dose | Step | What it is for |
|---|---|---|
| 2.5mg | 1 of 6 | The starter dose. Used for the first four weeks to allow your body to adjust to tirzepatide. Not intended for long-term weight management. |
| 5mg | 2 of 6 | The first maintenance dose. Where most clinically meaningful weight loss begins, with a side-effect profile that the majority of patients tolerate well. |
| 7.5mg | 3 of 6 | A mid-range escalation dose for patients whose weight loss has plateaued at 5mg. |
| 10mg | 4 of 6 | A maintenance dose used by many patients long term once they reach this strength. |
| 12.5mg | 5 of 6 | A higher escalation step for patients whose response has plateaued at 10mg. |
| 15mg | 6 of 6 | The maximum licensed dose. Reserved for patients who require it and have tolerated stepwise escalation through every prior strength. |
2.5mg: the starting dose
The first four weeks are about letting your gut get used to the medicine, not about losing weight. Appetite usually drops within the first week or two, but 2.5mg is not licensed as a maintenance dose and nobody stays on it long term. If you feel nothing at all in month one, that is normal and not a sign it will not work.
5mg: the first treatment dose
This is where weight loss properly starts for most people. It is also the dose a lot of people stay on. In the SURMOUNT-1 trial, people on 5mg lost an average of around 15 percent of their body weight over 72 weeks. If 5mg is controlling your appetite, there is no reason to go higher.
7.5mg to 12.5mg: going up only if needed
The prescriber will consider a higher dose if, after at least four weeks, appetite is creeping back and weight loss has stalled, and your side effects are mild. Each step up tends to bring a short return of nausea or loose stools for a week or so. If a step up makes you feel unwell, you can drop back to the previous dose. That is not a failure, it is how the medicine is meant to be used.
15mg: the maximum
15mg gave the biggest average loss in the trials, around 21 percent, but it also had the most side effects. It is a ceiling, not a goal. We only move people to 15mg when lower doses have clearly stopped working and they tolerate the medicine well.
Why you cannot skip steps
- The four week minimum on each dose is in the UK licence. Going faster is outside the licence and we will not prescribe it.
- Side effects are dose related. Jumping from 2.5mg to 7.5mg is the most common reason people stop treatment in the first two months.
- Weight loss is not faster on a higher dose if you cannot keep the food down. Slow and steady beats fast and sick.
Missed doses and changing your injection day
Missed a dose within the last four days (96 hours)? Take it now and keep your usual day. More than four days ago? Skip it, take the next one on your normal day. Never inject twice within three days.
You can move your injection day. Leave at least 72 hours between the last injection and the new day, then stick to the new day.
How we decide your next dose
Every repeat order is reviewed by the prescriber. They look at your current weight, how you are tolerating the dose, and what you tell us in the check in. If a step up is appropriate they will prescribe it. If not, they will say why. You can also ask to stay on your current dose at any point. Nobody is moved up automatically.
Sources: Mounjaro Summary of Product Characteristics (eMC), section 4.2 posology; BNF tirzepatide monograph; Jastreboff et al., SURMOUNT-1, New England Journal of Medicine 2022; NICE TA1026.