Mounjaro Dosage

Mounjaro is a prescription-only weight loss injection that makes you feel fuller for longer, so you lose more weight. It contains the active ingredient tirzepatide in increasing doses, starting at 2.5mg and increasing to a maximum maintenance dose of 15mg. You’ll follow a dosing schedule when you start Mounjaro and your doctor will advise you on when and how to change the dose, which is usually every 4 weeks.

In this guide, we take a look at the different Mounjaro doses, and how and when to change doses to get the most out of your treatment.

Dr Babak Ashrafi Clinical Lead for Service Development

Medically reviewed by

Dr Babak Ashrafi

Last reviewed: 27 Jun 2024

At a glance: Mounjaro dosage

Mounjaro weight loss injection dosage chart

What is the starting dose of Mounjaro?

The starting dose of Mounjaro is always 2.5mg, once a week, for 4 weeks. This is the same whether you're starting treatment for the first time, restarting after a break from Mounjaro, or switching from another weight loss injection. As each pen contains 4 doses, your first pen will last for 4 weeks.

You should only increase your dose if your doctor recommends it, or if you're following the dose schedule and it's time for your next dose increase. Increasing your dose faster than every 4 weeks or skipping doses on the dosing schedule could increase your risk of side effects and possibly put your health at risk.

What is titration?

The process of slowly increasing medication doses is called ‘titration’ and can happen over several days, weeks, or months. Mounjaro is on a titrating dose schedule to help your body get used to treatment while reducing the chances of getting side effects.

Our doctors are available to monitor how the medication affects you, to make sure you’re getting the most out of your new weight loss treatment with minimal discomfort.

Mounjaro dosage schedule

Mounjaro doses are titrated in steps of 2.5mg, with at least 4 weeks between dose changes. This means every 4 weeks, you’ll increase your dose by 2.5mg until you reach your maintenance dose.

What is the maintenance dose of Mounjaro?

Mounjaro has several maintenance doses: 5mg, 10mg, or 15mg. The maintenance dose is the highest dose of Mounjaro you'll take, and it's the dose you'll stay on for the rest of your treatment. The maintenance dose you keep depends on how you respond to the treatment, such as whether you have any side effects and your weight loss results.

The maximum maintenance dose is 15 mg, and you can't take more than this every week. If you're on a lower maintenance dose and decide you want to increase to a higher dose, you can do this at any time, as long as you don't have any serious side effects and you've waited at least 4 weeks before increasing the dose.

How many Mounjaro pens will I need?

The number of Mounjaro pens you will need depends on how long you continue to take Mounjaro to achieve your weight loss goals. Each pen lasts for 4 weeks and contains 4 doses. You’ll usually stick to each dose for 4 weeks before increasing unless you stay on a lower dose for longer. If you follow the dosage schedule with no issues, and want to increase to the maximum maintenance dose, this is how many pens you’ll need:

Weeks Dosage Number of Pens
1 - 4 2.5mg 1
5 - 8 5 mg 1
9 - 12 7.5mg 1
13 - 16 10mg 1
17 - 20 12.5mg 1
21+ 15mg 1+

Can I split my Mounjaro dose?

No, you shouldn’t split your dose under any circumstances. Splitting a dose means you don’t get the right amount of your medication, so it's not as effective. Doing this often could make it take longer to reach your weight loss goals and could put you at risk of side effects. It’s also difficult to split a dose from a pre-dosed injectable pen and you should never keep the needle in a pen to use for later.

You should only ever take your treatment as prescribed and directed by your doctor.

How long can I take Mounjaro for?

You can take Mounjaro for as long as your doctor prescribes it. This is usually until you’ve reached your weight loss goal. Studies have shown people can lose up to 22.5% of their starting weight while taking the highest maintenance dose of 15 mg after 72 weeks.

If you don’t lose at least 5% of your starting weight after 6 months of taking Mounjaro at your maintenance dose, your doctor may want to check if an alternative treatment is more suitable. Different people respond differently to certain medications, so changing might be more helpful for you in achieving your goals.

How do I change the dose on my pen?

So far, Mounjaro isn’t available in any other form than a pre-filled, injectable pen. This means it is not possible to change the dose on your Mounjaro pen. Each pen comes loaded with 4 doses, each with a fixed amount to be injected. Each pen lasts 4 weeks, and you should finish each pen before increasing your dose.

What if I can’t tolerate my new dose?

If you can’t tolerate your new dose (such as getting bothersome or severe side effects), you need to speak to your doctor as soon as possible. They may suggest staying on a lower dose and trying again after 4 weeks, or if you’re happy with your weight loss results, you may stay on the dose you can tolerate. Remember: It’s always possible to increase your dose again later.

It’s normal when starting a new Mounjaro dosage to get side effects, like feeling or being sick (nausea and vomiting). They are usually not severe and tend to go away over time. The following tips may help with these side effects:

  • Eat smaller meal portions throughout the day.
  • Try bland foods like crackers or toast.
  • Stop eating when you feel full.
  • Avoid fatty, greasy, or deep-fried foods, such as takeaways, dairy products like cheese and butter, and cakes or pastries.

What should I do if I miss a dose?

If you forget to take Mounjaro on your scheduled day and time:

  • You can still take it if it has been 4 days or less since you missed your dose. You can then carry on with treatment as normal.
  • If it’s been more than 4 days since you missed the dose, skip the missed dose and take the next injection as usual on your scheduled day.

Do not take 2 doses at once to make up for a missed dose. There should always be at least 3 days between your Mounjaro doses.

What if I want to change the day I take Mounjaro?

You can change the day you take your Mounjaro injection, but make sure you leave at least 3 days (72 hours) since you took the last injection dose. Your next dose can then be on any day you feel is suitable for you after this. For example, if you usually take your injection on a Wednesday at 9am, and you want to change this to Thursday at 9am, you’d need to wait until the following Thursday (8 days).

Once you’ve changed your dose, try to stick to the same day and time every week. Changing the day you take Mounjaro often could reduce its effectiveness.

Mounjaro FAQs

Do Mounjaro pens expire?

Yes, Mounjaro pens expire and you can check the expiry date on the pen label and carton. To find the expiry date, look for a date that follows with the letters ‘EXP.’ The expiry date always refers to the last day of the month. Do not use your Mounjaro pens after the expiry date.

How should I store my pens?

You can store your Mounjaro pens in the refrigerator between 2 °C – 8 °C. Do not store them in a freezer. If the medicine inside the pen gets frozen, do not use it even if you defrost it. You can also store your pen unrefrigerated (not above 30 ºC and away from direct sunlight) for up to 30 days. The pen must be discarded after this time.

How long does a Mounjaro pen last in storage?

When refrigerated at 2 °C – 8 °C, Mounjaro pens can last until the expiry date on the pen label. If you’re storing your pen in a cool dark place outside the refrigerator (under 30 °C), it’ll last 30 days from first use. After this time, the pen must be discarded.

What should I do with a broken Mounjaro pen?

Do not use your Mounjaro pen if you notice it is broken or damaged in any other way. Speak to your medicine supplier or pharmacist for more information. They may be able to dispose of it safely for you.

When is the best time to inject Mounjaro?

You can take your Mounjaro injection any time of the day, with or without food. It only matters that you take your injection on the same day and time every week. Find a time that works best for you and that you can easily stick to each week.

What should I do if I’m going on holiday?

It is possible to take your Mounjaro pen and needles with you on holiday. You should avoid exposing your pen to direct sunlight and temperatures above 30°C. You can keep your pen in its original carton to avoid sunlight exposure. It can be stored outside a refrigerator for up to 30 days, after which it should be discarded.

Any medicines, including your Mounjaro pens, should be kept in your hand luggage. You can also take a cool bag or cooling medication device if you want to keep your Mounjaro pen refrigerated – these are allowed on airplanes. When travelling to certain holiday destinations, you may need to show proof of your prescription and medical insurance. It’s best to check with the embassy or a local representative at your holiday destination beforehand.

Can I start Mounjaro at 5mg?

No. The starting dose of Mounjaro is 2.5mg once a week for the first 4 weeks. Your doctor will then put you on a maintenance dose of 5mg for 4 weeks, at which point your dose will be reviewed.

Even if you have previously taken Mounjaro at a higher dose, your doctor will always start you on a dose of 2.5mg once a week for at least 4 weeks.

Can I switch from Wegovy to Mounjaro?

Yes, you can switch from Wegovy to Mounjaro. You can speak to your doctor about switching, so they can guide you on doing it safely. You will need to stop Wegovy for 5 weeks before your doctor can safely start you on Mounjaro. This will be on the lowest starting dose of 2.5mg.


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