The Mounjaro KwikPen does not come with pen needles in the box, so you need to get compatible needles separately unless your treatment provider supplies them. The current UK user manual says to use a compatible pen needle and to speak to a healthcare professional if you are not sure which one to use.
This can be confusing when you are using Mounjaro for the first time. You may want to know which needles fit, what size to choose, how many you need and how to dispose of used needles safely. This guide covers those practical questions, along with some common problems you may come across when using the Mounjaro KwikPen.
Key things to know
- The Mounjaro KwikPen is supplied without pen needles. Some treatment providers may supply them separately, so check what is included with your prescription.
- You need a compatible pen needle for the KwikPen. If you are unsure which one to buy, ask your pharmacist or prescriber.
- Use a new pen needle for every injection.
- The KwikPen contains four doses of 0.6 ml, so you need four needles for one complete pen if you use one new needle for each dose.
- Used needles should be placed in an appropriate sharps container and should not be reused.
Which Pen Needles Fit the Mounjaro KwikPen?
The Mounjaro KwikPen user manual refers to a compatible pen needle and advises you to speak to a healthcare professional if you are unsure which needle to use.
This means you should not simply choose a needle because it looks similar to one you have used with another injection pen. Check the packaging or ask a pharmacist before using it.
Some commonly available pen needle brands include:
| Brand | Examples |
|---|---|
| Embecta | BD pen needles |
| Novo Nordisk | NovoFine, NovoFine Plus |
| Terumo | Pen needles |
| Owen Mumford | Unifine Pentips |
| GlucoRx | Compatible pen needles |
| Other suitable brands | Check compatibility before use |
Availability can vary between pharmacies and suppliers. If you already have a particular brand at home, ask a pharmacist to confirm that it is suitable for your Mounjaro KwikPen before using it.
The point worth checking
You may see websites claiming that only one particular brand of needle works with Mounjaro. That is not something you should assume. The Mounjaro user manual refers to a compatible pen needle rather than naming one specific brand.
The safest approach is simple: check the needle packaging and, if you are unsure, ask your pharmacist or prescriber.
What Size Should You Use?
Pen needles are described by their length, measured in millimetres, and their gauge, which describes the needle diameter.
Length
4 mm pen needles are commonly used for subcutaneous injections, but the right needle for you depends on the pen and your individual circumstances.
Rather than choosing a size based only on what you have seen online, check that the needle is compatible with your Mounjaro KwikPen. Your pharmacist or prescriber can help if you are unsure.
Gauge
Pen needles are available in different gauges. A higher gauge number generally means a thinner needle.
You may see 31G, 32G or 33G needles when shopping for pen needles. However, the most important point is that the needle is compatible with your pen and is used correctly.
The point that clears up most confusion
The needle is used to deliver the dose selected on your Mounjaro KwikPen. The needle size does not mean that you should change the dose on your pen.
Always follow the dose shown in your prescription and the instructions supplied with your KwikPen. If you are unsure whether a particular needle is suitable, ask a pharmacist rather than guessing.
Where to Buy Spare Needles in the UK
You may be able to get compatible pen needles from several places.
- Your treatment provider. Some online pharmacies and private treatment providers may supply pen needles with Mounjaro or sell them separately. Check what is included with your prescription.
- Community pharmacies. Ask your local pharmacist about suitable pen needles for the Mounjaro KwikPen. They can also help you choose the correct type if you are unsure.
- Online medical suppliers. Pen needles are available from various online suppliers. Check the product details carefully and make sure the needles are suitable for your pen before ordering.
Why prices vary
Pen needles are sold by different pharmacies and suppliers, so prices and pack sizes can vary. A larger pack may have a lower cost per needle, but only buy an amount that makes sense for your treatment and storage needs.
If you are unsure whether a cheaper product is suitable, ask a pharmacist before using it.
What about Wegovy?
Wegovy and Mounjaro are different medicines and use different injection pens. Some pen needles may be suitable for more than one type of injection pen, but you should not assume that a needle that works with one pen will automatically be suitable for another.
If you are switching between Wegovy and Mounjaro, check the needle requirements for your new pen or ask your pharmacist.
How Many Do You Need?
Each Mounjaro KwikPen contains four doses of 0.6 ml. Mounjaro is given once a week, so one pen provides four weekly doses.
You should use a new pen needle for every injection. This means you need four needles for each complete KwikPen.
How many spare needles you buy will depend on how many pens you use and the pack sizes available from your supplier.
Never reuse a needle
Pen needles are intended for single use. Using a new needle each time helps you follow the instructions for safe injection and avoids using a needle that may be damaged, contaminated or blocked.
Do not share pen needles with anyone else.
Disposal and Sharps Bin Guidance
Used pen needles should be placed in a suitable sharps container rather than being put loose into household waste or recycling.
Do not leave used needles where children or other people could come into contact with them. Follow your local pharmacy or council guidance for getting rid of a full sharps container, as collection arrangements can vary by area.
For advice about disposing of your Mounjaro pen itself, follow the instructions supplied with your medicine or ask your pharmacist. The UK prescribing information states that unused medicine and waste material should be disposed of according to local requirements.
Common Problems
The needle will not attach properly
Do not force the needle onto the pen. Check that you have the correct compatible pen needle and that it is being attached according to the instructions supplied with your KwikPen.
If it still does not fit, ask your pharmacist to check the needle and pen before you use them.
Nothing comes out when priming
Priming helps check that the pen and needle are working before you inject. The Mounjaro KwikPen instructions explain what to do if no medicine appears during priming. This includes repeating the priming steps a limited number of times and changing the needle if needed.
Do not force the pen or keep trying indefinitely. If you still cannot prime it correctly, contact your pharmacist, doctor or the manufacturer for advice.
You are not sure the dose went in
Do not automatically inject another full dose.
The KwikPen instructions explain that if the dose window does not show the expected result, you should follow the instructions rather than starting the injection again or redialling the dose. If you still think you did not receive the full dose, do not repeat the injection. Contact your pharmacist, prescriber or healthcare team for advice.
If you feel unwell after an injection or develop symptoms of a serious allergic reaction, seek urgent medical help.
Medical Disclaimer
This article is for general information only and does not replace individual medical advice or the instructions supplied with your Mounjaro KwikPen.
Always use a compatible pen needle and follow the instructions provided with your medicine. Use a new needle for each injection and dispose of used needles safely.
If you are unsure which needle to buy, how to attach it, how to prime your pen or what to do after an injection problem, speak to your pharmacist, prescriber or healthcare team.
