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Mounjaro FAQ and Instructional Video
Mounjaro FAQ and Instructional Video
Updated over 2 months ago

Eli Lilly have recently launched Mounjaro in the UK. We've put together some answers to some frequently asked questions you may have. You can find more information about Mounjaro on our website here.

What is Mounjaro?

Mounjaro is a medication licensed for the treatment of overweight or obese patients. When used in conjunction with a balanced diet and regular physical activity, Mounjaro, which contains the active ingredient tirzepatide, helps individuals lose weight by increasing energy expenditure and regulating appetite. Tirzepatide acts as a dual GIP and GLP-1 receptor agonist, mimicking the natural hormones GIP and GLP-1.

Mounjaro Safety Information

What does Mounjaro do?

Mounjaro is prescribed for the long-term management of weight after clinical trials demonstrated its suitability for weight loss.

The principle mechanism of Mounjaro (tirzepatide) is its activation of both the GIP and GLP-1 receptors. It does this by mimicking the incretin hormones GIP and GLP-1 which play a significant role in insulin secretion, satiety and energy balance. By acting on dual receptors, tirzepatide improves blood sugar levels and enhances the feeling of fullness - key factors in achieving weight loss.


Like all medications, the effects will only last as long as you take it, but when used correctly and mixed with a healthy diet and a good exercise regimen, it will help you lose weight. For more information on this, see our blog article here.

What’s the difference between Mounjaro and Wegovy?

Wegovy mimics the GLP-1 hormone whereas Mounjaro mimics the effect of both GLP-1 hormone and GIP hormones. While both are effective treatments for weight loss, clinical studies conducted over a similar timeframe show that Mounjaro leads to greater weight loss than Wegovy.

You can find out more about the differences between these two medications on our blog here.

What titrations will be available for Mounjaro?

Mounjaro comes in 6 different titrations. Patients will typically be started at the lowest dose, with a gradual increase in the titration strength.

Everyone responds to the medication differently and so our clinicians will ensure the dose you are on is right for you

  • 2.5mg

  • 5mg

  • 7.5mg

  • 10mg

  • 12.5mg

  • 15mg

For information and guidance on the potential side effects of Mounjaro, see our blog article here.

What do I do if I see air bubbles in my pen?

An air bubble in the Mounjaro pen is a small pocket of air that may be present when preparing the medication for injection. It can occur during priming or air can also enter through the injection process. When holding the pen, try to keep it steady and avoid shaking or tapping it as this can agitate any existing bubbles. Sometimes, air bubbles can occur due to temperature changes.

It is generally safe to inject Mounjaro with a small air bubble. The tiny amount of air will not cause harm or impact the effectiveness of the medication. Injecting a small amount of air along with your prescribed dose of Mounjaro will not alter its intended dosage or therapeutic effect; this is only an issue if the air bubble is large.

Mounjaro is injected subcutaneously – which is under the skin. Air bubbles are only really of concern if injected directly into a blood vessel.

If you accidentally inject a large amount of air along with your dose of Mounjaro, monitor yourself for any unusual symptoms and consult your healthcare provider if you experience adverse reactions.

Why is there excess medication left in my pen?

The pen is licensed for four doses but there is additional excess medication in the pen. Each pen contains 3mL and each dose is approximately 0.6mL, which means there will normally be a slight amount of solution left over in the pen.

For this reason, please do not use the liquid level within the window of the pen as a marker for how many doses are left.

The manufacturer does not advise using over 4 doses for a single pen, as they cannot guarantee the excess solution is calibrated to deliver further doses correctly.

Are there any side effects?

Like all medicines, Mounjaro can cause side effects, although not everybody gets them. Most patients find that the side effects resolve with time, once your body is accustomed to the medication. If your side effects are not resolving, please speak to one of our clinicians who can advise you on next steps.

Further information can be found on our Mounjaro safety information page or refer to the Patient Information Leaflet that comes with the medication.

When can I take Mounjaro?

Mounjaro is a once-weekly injectable. There is not a specific time of day where you need to administer it, as long as it’s the same day each week and the same time period. You can take Mounjaro with or without food. You may change the day of the week you use Mounjaro as long as your last dose was taken 3 or more days before.

How do I take Mounjaro?

For detailed instructions, please refer to the leaflet inside your medication box

Step 1: Select the correct pre-filled Kwikpen

  1. Select the pen labelled with the correct weekly dosage.

  2. Check the pen to make sure it isn’t damaged, the expiration date hasn’t passed, and that the medicine is clear and colourless/slightly yellow in the window within the pen.

  3. Pull off the pen cap.

  4. Wipe the red inner seal of the pen with one of the wipes.

  5. Always use a new needle for each injection. Take a needle when you are ready to take your injection. Check the paper tab and the outer needle cap for damages. If you see any damage, this could affect sterility. Dispose of it and use a new needle. Tear off the paper tab from the needle, then push the needle onto the pen and twist until it's secure.

  6. You must remove both caps from the needle.

  7. Prime the pen. Slowly turn the dose knob until you hear 2 clicks and the extended line is shown in the dose window. This is the prime position. You can keep turning the dose knob in either direction until the prime position lines up to the dose indicator. With the needle pointing upwards, tap the cartridge holder gently to collect air bubbles at the top. Release some medicine into the air by pushing the dose knob in until it stops, then slowly count to 5 while holding the dose knob. The ‘0’ icon must be shown in the dose window. A small amount of medicine should come out the tip of the needle. If not, repeat these steps an additional 2 times. On the 3rd time, change the pen needle and repeat again.

Step 2: Decide where to inject

  1. Decide where on your body you’ll inject the medicine. You can either inject it into your stomach (at least 2 inches from your belly button) or in your upper legs on the front of your thighs. If someone else is helping you, they can inject it into your upper arm for you.

  2. You can inject the pen in the same body part each week, but make sure it isn’t in exactly the same spot.

  3. Expose the area of skin you will be injecting into and ensure there is no visible break in or damage to the skin.

  4. Clean the chosen area with the other alcohol wipe and let it dry.

Step 3: Inject your dose

  1. Turn the dose knob until it stops and the ‘1’ icon is shown in the dose window.

  2. Position the pen at the injection site, ensuring you can see the pen window.

  3. Push the pen firmly against the skin and apply continuous pressure.

  4. Press and hold down the dose knob until it stops, and count to 5 whilst holding the dose knob. The ‘0’ icon should be visible in the dose window before removing the needle from the skin.

  5. Remove the needle from your skin. If blood appears at the injection site, press on it lightly with a clean tissue, but do not rub the area.

Step 4: After the injection

  1. Lead the needle tip into the outer needle cap on a flat surface without touching the needle or the outer needle cap. Once the needle is covered, carefully push the outer needle cap completely on.

  2. Unscrew the needle and dispose of it in your sharps bin.

  3. Never try to put the inner needle cap back on the needle. You may stick yourself with the needle.

  4. Always dispose of the needle immediately after each injection to prevent blocked needles, contamination, infection and inaccurate dosing. Never store your pen with the needle attached.

  5. Put the pen cap on your pen after each use to protect Mounjaro from light.

Always take this medicine exactly as prescribed for you. Check with a Numan clinician if you are not sure.

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