How To Inject Mounjaro: A Step-by-Step Guide

Mounjaro is a popular once-weekly weight loss injection. It contains the active ingredient tirzepatide, which suppresses your appetite, making it easier to follow a calorie-controlled diet.

Scientific research has shown that the highest Mounjaro maintenance dose of 15mg per week can help people lose up to 22.5% of their initial body weight.

Before you inject Mounjaro, you need to choose an injection site. Mounjaro is injected just under the skin of your:

• stomach
• upper thigh
• upper arm – you may need help from someone else if you inject here

You can inject in the same area each week but you must rotate the injection site in that area. Alternatively, you can change the injection site location each week. For example, you might inject in your stomach in week 1, your upper thigh in week 2, your upper arm in week 3, and so on.

With your first few injections, you’ll be able to find what works for you.

1. If injecting Mounjaro on your own, choose either the abdomen or upper legs. If someone is helping you, they can inject into your upper arm or the other injection sites.
2. Split the injection site into 2 sections on each side of your body (see the image below for an idea of what this looks like). Rotate the site each week so you’ll only be injecting into the same area at least once every 4 weeks.
3. When injecting into the stomach, always leave a 5cm gap from your belly button (navel).
4. Always inject at least one finger width away from your last injection.

Before injecting Mounjaro, there are a few things you need to do to prepare.

Mounjaro will be delivered in a box containing:

• a pre-filled injection pen that includes 4 doses, 1 per week
• a patient information leaflet
• an instruction leaflet on how to use Mounjaro

It is important to inject Mounjaro on the same day each week because it:

• ensures a consistent amount of the medication remains in your body
• helps your body get used to the medication, reducing the risk of side effects

When you are ready to inject Mounjaro:

1. Wash your hands with warm, soapy water and dry them thoroughly.
2. Check the correct dosage is displayed on the original packaging and that it is within date.
3. Take the pen out of the box and inspect for any damage.
4. Remove the protective cap from the pen and check the dosage window to make sure the liquid is clear and free from any debris or particles – if the solution is frozen, do not use it.
5. Get a new needle ready close-by, and make sure it’s not unsealed, bent, or damaged in any way.

The Mounjaro ‘KwikPen’ is a single-patient-use pen that contains 4 fixed doses, with 1 dose injected each week. That means 1 pen provides 4 weeks of treatment. Once all 4 doses have been used, you can throw the pen away.

Once you have performed steps 1 to 4 in the ‘When you are ready to inject Mounjaro’ section, you are ready to administer your medication.

First, you will need to prime your pen:

1. Wipe the inner red seal with a swab.

2. Select a new pen needle – always use a new needle for each injection and make sure it’s not broken or bent in any way – and remove the paper tab from the outer needle shield.

3. Push the capped needle straight onto the pen and turn it clockwise until it’s tightly secured on the pen.

4. Remove the outer needle shield and place it to one side – you will need this later – then remove the inner needle shield and throw it in your household rubbish bin.

5. Slowly turn the dose knob until you hear 2 clicks and the extended line is displayed in the dose window. This is the prime position. If you need to, you can turn the dose knob in either direction until it lines up to the dose indicator.

6. Holding your pen so the needle is pointing up in the air, gently tap the cartridge holder to send any air bubbles to the top.

7. Release some medicine into the air by pushing the dose knob until it stops, then slowly count to 5. The ‘0’ icon should be displayed in the dose window – do not inject it into your body. If a small amount of medication is released from the tip of the pen needle, your pen is primed.

How to inject Mounjaro:

8. Choose your injection site. You don’t need to squeeze or hold the area of skin you want to inject.

9. Turn the dose knob until it stops and the ‘1’ icon is displayed in the dose window – this represents one 0.6ml dose.

10. Insert the needle into the skin at your chosen injection site. Make sure you or the person doing the injection can see the dose counter.

11. Push the dose knob until it stops, then slowly count to 5 while still holding the dose knob in. Check the ‘0’ icon is shown in the dose window before removing the needle from your skin.

12. Pull the needle from your skin. It is normal to see a small drop of medicine at the end of the needle after removal, it will not affect your treatment.

After the injection is done:

13. Carefully replace the outer needle shield onto the needle and discard it in your sharps bin.

14. Replace the pen cap and store your pen away until your next dose.

Your used Mounjaro pen can be stored at room temperature, up to 30 degrees Celsius (°C), for no more than 30 days. Keep it away from direct light and in its original packaging. You can also store it in a fridge between 2 and 8°C and if you choose this method, it does not need to be discarded after 30 days.

Any unused pens should be stored in the fridge between 2 and 8°C until ready for use.

Post injection care

After you have injected Mounjaro, you might notice a small amount of blood where the needle entered your skin. This is usually nothing to worry about and you should lightly press a small piece of gauze or cotton wool on the injection site.

You may also notice a small amount of bruising at the injection site, this should fade away within a few days.

How do I reduce pain during and after injecting Mounjaro?

You can reduce pain and irritation during and after injecting Mounjaro by:

• taking an antihistamine tablet
• applying an over-the-counter antihistamine cream to the affected area – a pharmacist may help you
• changing your injection site weekly
• cleaning the skin before injecting Mounjaro with a swab
• applying an ice pack to the injection site to numb the area and prevent irritation before injecting your medication
• taking over-the-counter painkillers if you feel sore after injecting
• applying a cold compress to reduce swelling after the injection

Some people may experience a reaction to Mounjaro at the site where they inserted the needle.

Clinical trials show that Mounjaro injection site reactions were reported in 3.2% of patients compared to 1.7% of patients given a placebo.

Up to 1 in 10 people may experience hypersensitivity reactions when using Mounjaro or other weight loss injections. Common reactions include:

• skin rashes
• itching
• eczema
• swelling
• redness

If you experience any of these symptoms, let your doctor know. They may suggest trying a lower dose, changing the injection site, or using a topical over-the-counter cream to relieve any irritation.

It should not be very painful to inject Mounjaro – any severe irritation, swelling, or redness should be seen by a doctor straight away. This could be a sign of an allergic reaction.