Mounjaro® Injectable Pen

Mounjaro® is a once-weekly injection that’s given in the arm, leg or abdomen. It uses a very small, fine needle for a near-painless injection just below the surface of the skin. The Mounjaro® pen comes with clear instructions for use. It has a simple dial in order to deliver the right amount of medication for your treatment stage. Once you’ve had the injection, remove and dispose of the needle in a sharps bin. Replace the cap and store as instructed.

Each Mounjaro® pen contains 4 dosages. Given this is a weekly dosage, one pen lasts 4 weeks. The needles should be disposed of after each administration.

The strength of the injection is increased every 4 weeks until the highest tolerated dose, or the maximum dose is reached.

The clinical team will review your weight with every order to ensure this product is working for you. When you have used your highest tolerated dose for 6 months, we will review your progress. For us to continue prescribing Mounjaro® to you, you’ll need to have lost around 5% of your initial body weight. You are likely to be able to continue using it for up to two years with clinical guidance.

It’s safe to switch treatments during your treatment, provided this is appropriately supervised by an expert clinician like we have at Juniper.  Switching from Mounjaro to Wegovy is considered very safe, and generally, anyone who can be treated with Mounjaro can be safely treated with Wegovy.  Wegovy has the added advantage of not affecting the contraceptive pill or certain other medicines, which can make it a safer treatment option for some.

It’s important that the correct starting dose is prescribed when switching, along with appropriate advice and ongoing support to manage any issues that could arise.

If you experience symptoms such as persistent nausea, vomiting and diarrhoea with your current Mounjaro® dose, speak to our customer care team for advice. We may recommend continuing or decreasing your dose to see if that helps improve your tolerance.

We can also give you tips to help manage any symptoms and get maximum benefit from the medication. It’s important to not increase your Mounjaro® dose until your body is ready, so make sure you contact Juniper if you have persistent side effects.

Yes, Mounjaro® KwikPen is licensed for weight loss in the UK.

Mounjaro® should be stored in a refrigerator and kept at 2–8°C, or in a cooler/ice pack when travelling. Don’t freeze it, or use it if it has been frozen. Keep the cap on when the pen isn’t in use to protect it from light.

If a dose is missed, it should be administered as soon as possible, within 4 days after the missed dose. If more than 4 days have passed, skip the missed dose and administer the next dose on the regularly scheduled day. In each case, patients can then resume their regular once weekly dosing schedule.

Mounjaro® should not be used during pregnancy.

If you are of childbearing age and sexually active, you should use contraception while taking Mounjaro®.

As Mounjaro® may reduce the effectiveness of your oral contraceptive pill, you must use an additional barrier form of contraception, such as condoms, or switch to a non-oral method such as an IUD or implant.

Recent research has shown that Mounjaro® may reduce the effectiveness of your oral contraceptive pill. This could increase the risk of an unplanned pregnancy.

To stay protected, you must use an additional barrier form of contraception, such as condoms, or switch to a non-oral method such as an IUD or implant while using Mounjaro®.

If you experience severe diarrhoea that lasts for over 24 hours, or vomiting within three hours of taking your oral contraceptive pill, you may need a repeat dose of your oral contraceptive pill. Contact your GP or call 111 for medical advice if this occurs.

If you experience persistent vomiting or diarrhoea, consider a non-oral method of contraception. Contact your GP to discuss your options.

If you are planning on becoming pregnant, it is recommended that you wait at least one month before your last dose of Mounjaro® before trying.

If you are planning to become pregnant, it is recommended that you wait at least one month after your last dose of Mounjaro® before trying.

If you are planning to become pregnant, it is recommended that you wait at least one month after your last dose of Mounjaro® before trying.

Yes, switching to Wegovy is a great option, especially if keeping your treatment cost low is important to you.  Our real-world results from treating tens of thousands of patients with Wegovy shows that patients typically lose 18% of their total body weight in just over a year, with the support of the Juniper Programme.

Based on evidence from clinical trial and our real-world data, Mounjaro results in slightly more weight loss, on average, though individual results will vary.  However, with our real-world data showing patients typically achieve 18% weight loss in just over a year with Wegovy, this is likely to meet most patients’ weight loss needs for a more affordable cost.

The kinds of side effects that can be experienced with Mounjaro and Wegovy are almost identical, and the more common side effects such as nausea, constipation, diarrhoea or vomiting can occur with either treatment.  With both medicines, the risk of side effects increases with higher doses and that’s why we take a personalised and cautious approach to optimise your dose to limit the impact of any side effects.

Everyone’s response to medication is different. It’s possible that you may have a different side effect experience when you switch medications, especially at the start. It’s also possible to have some side effects with your current treatment that disappear when you switch.  Remember, the Juniper Team are here to support you through the switching phase to optimise your treatment, just reach out if you need help.


It’s safe to switch treatments during your treatment, provided this is appropriately supervised by an expert clinician like we have at Juniper.  Switching from Mounjaro to Wegovy is considered very safe, and generally, anyone who can be treated with Mounjaro can be safely treated with Wegovy.  Wegovy has the added advantage of not affecting the contraceptive pill or certain other medicines, which can make it a safer treatment option for some.

It’s important that the correct starting dose is prescribed when switching, along with appropriate advice and ongoing support to manage any issues that could arise.

No, you don’t have to pause when switching at Juniper - we make this seamless. When switching from Mounjaro to Wegovy, we will advise you to wait the usual 7 days between doses before commencing with your first Wegovy dose.

Switching must be appropriately supervised by an expert clinician like we have at Juniper.  It’s important that the correct starting dose is prescribed when switching, along with appropriate advice and ongoing support to manage any issues that could arise, including making dose adjustments.

Yes, your Juniper prescriber and our Care Team clinicians are on-hand to support you through the process.  Whether it’s advice on using a different kind of pen, concerns about side effects, or needing to make further adjustments to your dose.

At Juniper we’ve made the switching experience as quick and painless as possible.  If you’re doing well on your current treatment, we’ll usually be able to switch you straight away if that’s your wish.

If you’ve recently experienced side effects or have questions or concerns about switching we will arrange a review consultation with your prescriber so that you can make sure you’re comfortable and your prescriber can individually assess the right dose to switch to. This might take a day or two to complete.