Mounjaro dosage: starting dose, dosing schedule and increasing safely

Dosing schedule: from 2.5 to 15 mg

The Mounjaro dosing schedule follows fixed steps of 2.5 mg, each time with at least 4 weeks per step. This schedule comes from the official EMA product information, the European medicines authority.

Two things stand out in this schedule. First: the 4-week waiting time per step is a minimum, not a race. Staying on a step for longer is always allowed, increasing faster is not. Second: by no means everyone goes through all the steps. Many people stay on 5 or 10 mg, simply because that dose does enough for them.

You inject Mounjaro once a week, at a fixed time, just under the skin of your abdomen, thigh or upper arm. Rotate the injection site each week to prevent skin irritation.

With us, this schedule runs in step with the supervision: every 4 weeks our doctor evaluates with you how things are going, exactly in the rhythm in which a dose step can come up. Increasing is therefore never automatic, but always a considered decision based on your results and your side effects.

Can you start on 5 mg?

No, starting on 5 mg is not recommended. The official guidance states that every user starts with 2.5 mg per week, even if you want to lose a lot of weight or previously used a different medicine.

The reason is simple: among other things, tirzepatide slows your gastric emptying. If you skip the adjustment phase, the risk of significant nausea, vomiting or diarrhoea is considerably higher. Those 4 weeks on 2.5 mg are therefore not wasted time, but the basis for a treatment you can keep up.

There is one situation in which your doctor can deviate from the standard schedule: if you're switching from another medicine in the same group. Even then, the doctor decides the starting dose, never you. If you want to know what such a medically supervised treatment looks like in practice, read more about medical weight loss with injections.

Is 7.5 mg stronger than 5 mg?

Yes, 7.5 mg Mounjaro is stronger than 5 mg: each injection contains more active substance, and on average a higher dose leads to more weight loss. But more is not automatically better, because a higher dose also brings a greater risk of side effects.

The differences per dose have been well researched. In the SURMOUNT-1 trial, published in The New England Journal of Medicine, participants with obesity lost an average of 15.0% of their body weight after 72 weeks on 5 mg, 19.5% on 10 mg and 20.9% on 15 mg tirzepatide. The placebo group lost an average of 3.1%.

Do note what these figures do not say. They are averages from a study in which medication was combined with an adjusted diet and more exercise; your result may turn out higher or lower. And the difference between 10 and 15 mg is small on average, while the risk of gastrointestinal complaints increases at higher doses. That's why a good doctor doesn't look for the highest dose, but for the lowest dose at which you get good results with acceptable side effects.

How many mg is 1 dose? The Mounjaro pen explained

One dose of Mounjaro contains exactly the strength stated on your pen: 2.5, 5, 7.5, 10, 12.5 or 15 mg tirzepatide. You don't need to measure or set anything yourself; the pen automatically delivers the full dose with each injection. Read more about the Mounjaro diet.

In the Netherlands, Mounjaro is mainly supplied as the KwikPen. This is a prefilled pen with 4 doses of the same strength, each 0.6 ml of liquid. With weekly use, one KwikPen therefore lasts 4 weeks. There are also prefilled pens and injection vials with a single dose of 0.5 ml; which form you receive depends on what the pharmacy supplies.

If you move up a dose step, you get a new pen with the higher strength. Never use two injections of a lower strength to mimic a higher dose: that means deviating from the registered schedule and increases the risk of side effects. You can read what a pen costs per strength and how the price changes per dose step in our article on the Mounjaro price.

Mounjaro instructions for use: how to inject the right dose

You inject Mounjaro yourself, once a week, just under the skin. That sounds more daunting than it is: the needle is thin, the pen does the work and after the first time most people are done within a minute.

The basic steps are always the same:

1. Choose an injection site: your abdomen (at least 5 centimetres from the navel), the front of your thigh, or the back of your upper arm if someone else gives the injection.
2. Rotate the site every week, for example alternating left and right, to prevent skin irritation and hardening of the tissue under the skin.
3. Inject at a fixed time, on the same day every week. It doesn't matter whether you do that with or without a meal; tirzepatide works independently of your mealtimes.
4. Check the liquid beforehand: it should be clear and colourless to pale yellow.

Store your pens in the fridge and read the patient information leaflet for your specific pen before the first injection; the storage period outside the fridge and the exact steps differ per type of pen. With your first delivery, your doctor or pharmacy will explain exactly how your pen works, so you can give the first injection with confidence.

Tirzepatide dosage: how the active substance works

Tirzepatide is the active substance in Mounjaro, so the dose in milligrams always refers to the amount of tirzepatide per injection. In practice, "Mounjaro dosage" and "tirzepatide dosage" therefore mean the same thing.

Tirzepatide mimics two gut hormones that your body makes itself: GIP and GLP-1. These hormones are normally released after eating and signal to your brain that you're full. The medicine strengthens that signal, slows your gastric emptying and so dampens your feeling of hunger and the urge to snack. You eat less without it constantly costing willpower; for most people that is the biggest difference from every diet they tried before.

That dual action on GIP and GLP-1 makes tirzepatide different from semaglutide, the active substance in Ozempic and Wegovy, which only acts on GLP-1. The doses also differ: you can never translate the milligrams of one medicine directly into the other. If you're unsure which medicine suits you, read our comparison Mounjaro vs Ozempic. The choice itself is always up to the doctor.

Because your body has to get used to this strengthened hormone signal, tirzepatide only works safely with the slow dosing schedule. That also explains why the effect comes gradually: the medicine has to build up in your system step by step.

Side effects per dose step

Most side effects of Mounjaro are gastrointestinal complaints, and they mainly occur in the days after a dose increase. Nausea comes first, followed by diarrhoea, constipation and sometimes vomiting. In most cases the complaints are mild to moderate and decrease as soon as your body has got used to the new step.

Per phase, it usually looks like this:

• 2.5 mg (start): in the first weeks you may notice slight nausea or a full feeling. Large or fatty meals are harder to handle.
• 5 to 10 mg: around each increase the complaints can briefly return. Between the steps, most people feel normal.
• 12.5 and 15 mg: the risk of gastrointestinal complaints is greatest here. That's exactly why this is only useful if the results on lower doses fall short and you tolerate the medicine well.

You can do a lot yourself to limit the complaints: eat smaller portions, chew calmly, go easy on fat and alcohol and drink enough water. If that doesn't help or complaints persist, the solution is often not to stop, but to stay on the current step for longer or go back a step. That is exactly why quick contact with your doctor is so important, especially with side effects. You'll find a full overview, including the rare complaints for which you should call straight away, in our article on Mounjaro side effects. Read more about how fast Mounjaro works.

Worried about side effects, or would you rather not have to work out for yourself which dose is sensible? At Qlinic you're supervised by your own BIG-registered doctor who personally evaluates your progress with you every 4 weeks. Take the eligibility check →

Missed a dose or changing your injection day?

If you've missed an injection, the 4-day rule applies: within 4 days you can still take the missed dose. If more than 4 days have passed, skip the dose and simply inject again on your usual injection day. Never take a double dose to make up for a missed injection.

Want to move your usual injection day, for example from Monday to Friday? That's allowed, as long as there are at least 3 days (72 hours) between two injections. After that, you continue your weekly rhythm on the new day.

A few practical tips also make forgetting a lot less likely. Link your injection to a fixed moment, such as Sunday morning after breakfast, and set a weekly reminder on your phone. You can also find independent information on using tirzepatide, including these rules for a missed dose, on apotheek.nl (the patient information website of Dutch pharmacists). If you're unsure about your situation, always give your doctor or pharmacy a quick call instead of doing the maths yourself.

When to increase, and when not to?

Increasing makes sense if three things are true at the same time: you tolerate your current dose well, your weight loss is stalling and your doctor considers the next step medically responsible. If one of the three is missing, waiting is usually the better choice.

There are good reasons not to increase. If you're losing weight steadily on your current dose, a higher dose mainly adds a risk of side effects. If you've just had an increase, your body needs the full 4 weeks or longer to adjust. And sometimes a plateau isn't a dose problem, but a signal to look at diet, sleep or stress together with your doctor.

Important to know: Mounjaro is a prescription medicine, and adjusting the dose is always the doctor's decision. Never buy the medicine online without a prescription. The College ter Beoordeling van Geneesmiddelen (the Medicines Evaluation Board, the Dutch medicines regulator) explicitly warns against that route: selling without a prescription is prohibited in the Netherlands, you don't know what you're buying and counterfeit pens have already put people in hospital.

The safe route goes through a doctor who assesses whether the medicine suits you, usually with a BMI of 30 or higher. Curious where you stand? Use our BMI calculator as a first step.

That's how it works with us too. After the eligibility check and an intake consultation, our doctor assesses whether medical weight loss suits you. After that, your medication is delivered to your home via the pharmacy and you evaluate your progress personally with the same doctor every 4 weeks. Increasing, waiting longer, pausing or stopping: everything is done in consultation with the doctor.

Tapering off, pausing or stopping

In principle you can stop Mounjaro at any time, but always do it in consultation with your doctor. There is no mandatory tapering schedule as there is with some other medicines; your doctor will, however, look with you at what is sensible in your situation, for example temporarily going back to a lower dose instead of stopping abruptly.

Be realistic with yourself about what happens next. Tirzepatide dampens your feeling of hunger as long as you use it; after stopping, your normal appetite gradually returns. Without lasting changes to your eating pattern and activity, some of the weight you lost may then come back. That is not a failure, but the reason why a good treatment is about more than medication: it's also about habits you can keep up.

A pause can sometimes be a deliberate choice, for example around an operation, with persistent side effects or when you want to become pregnant; you also agree on that with your doctor beforehand. With us, too, you discuss pausing or stopping with your regular doctor, and together you look at how to maintain the result afterwards.

Not losing weight, whatever you try? Find out without obligation whether medical weight loss under the supervision of our regular doctor suits your situation. Take the eligibility check →

Frequently asked questions about Mounjaro dosage

What is the dosing schedule for Mounjaro?

The Mounjaro dosing schedule starts with 2.5 mg per week for 4 weeks, then 5 mg per week. If needed, the doctor then increases the dose in steps of 2.5 mg, with at least 4 weeks per step, to a maximum of 15 mg per week. The recommended maintenance doses are 5, 10 and 15 mg.

Can I start Mounjaro on 5 mg?

No, starting on 5 mg is not recommended. According to the official product information, everyone starts with 2.5 mg per week, so the body can adjust for 4 weeks and the risk of nausea and other gastrointestinal complaints stays as small as possible. Only a doctor can deviate from this in exceptional cases.

Is 7.5 mg Mounjaro stronger than 5 mg?

Yes, 7.5 mg contains one and a half times as much tirzepatide as 5 mg and on average gives more weight loss, but also a greater risk of side effects. A higher dose is therefore only useful if the results on 5 mg fall short and you tolerate the medicine well, as assessed by your doctor.

How many mg is 1 dose of Mounjaro?

One dose of Mounjaro contains 2.5, 5, 7.5, 10, 12.5 or 15 mg tirzepatide, depending on the strength of your pen. The pen automatically delivers the full dose with each injection; with the KwikPen that is 0.6 ml of liquid per dose.

How long does 1 Mounjaro pen last?

A Mounjaro KwikPen contains 4 doses of the same strength and so, with weekly use, lasts exactly 4 weeks. Prefilled pens with a single dose are used once per injection.

What should I do if I've missed a dose of Mounjaro?

Take the missed dose anyway if you can do so within 4 days of the planned time. If it's longer, skip the dose and inject on your next usual injection day. Never take a double dose and always leave at least 3 days between two injections.