If you are getting a single Mounjaro pen, one practical thing to arrange at the same time is your needles, because needles are not included with the pen. The Mounjaro KwikPen uses compatible screw on pen needles, and a new needle should be used for each injection. The UK manufacturer's Instructions for Use state that the choice of needle gauge and length is at the discretion of the doctor or pharmacist. If you already have your pen or are about to start using it, it is worth arranging your compatible needles in advance so you have enough for your injections and can dispose of each used needle safely in a sharps container.
The good news is that this is usually straightforward to arrange. This guide covers how many needles a single pen needs, what type to buy, whether they are single use, and where to get them, so you can have everything ready before your first injection.
How Many Needles for One Pen?
A single Mounjaro KwikPen is designed to provide four once weekly doses, and a new needle should be used for each injection. Therefore, you need at least four compatible needles for one pen. Keeping one or two spare compatible needles available may also be useful in case a needle is damaged, dropped or otherwise cannot be used.
Pen needles are commonly sold in multipacks, so a single pack may contain enough needles for several Mounjaro pens. You do not need to buy them specifically for each pen. One box may provide enough needles for multiple pens, depending on the pack size.
What Type of Pen Needles to Buy
The KwikPen uses compatible screw on pen needles, so you need a suitable pen needle rather than a Mounjaro specific needle. Needle gauge describes the thickness of the needle, with a higher gauge generally indicating a finer needle. The UK manufacturer does not specify one particular gauge or length for every patient. The choice of needle gauge and length is at the discretion of the doctor or pharmacist.
If you want more detail on sizes and gauges and how to choose between them, see our dedicated needle size guide, or ask your pharmacist. When choosing pen needles, look for a product that is confirmed as compatible with the Mounjaro KwikPen and follow the advice of your doctor or pharmacist regarding needle length and gauge.
What "Disposable" Means Here
Pen needles are designed for single use. You attach a new needle for each weekly injection and dispose of it afterwards in an appropriate sharps container. Reusing needles is not recommended, as advised in the manufacturer's Instructions for Use.
So, "disposable needles for a Mounjaro pen" simply means the pen needles are used once and then discarded. For one pen, that means four needles across the four weekly doses.
Where to Buy Needles for a Single Pen
Compatible pen needles, including replacement Mounjaro needles, are available from some pharmacies, online pharmacies and healthcare retailers, although availability can vary. These are standard pen needles used with a range of injectable medicines and devices. However, compatibility should be checked for the specific pen rather than assuming that a particular needle will fit every device.
- High street pharmacies and other pharmacies, subject to local availability and the pharmacy's supply arrangements.
- Online pharmacies, including possibly the one supplying your Mounjaro, as some may offer compatible needles with your order.
- Some larger health retailers.
Check whether the pharmacy supplying your Mounjaro also provides compatible pen needles, so you know whether you need to purchase them separately. Prices and pack sizes vary by brand and retailer, so you can compare options if cost matters. If you are unsure which compatible option to buy, check with the pharmacy or your healthcare professional.
Get a Sharps Bin at the Same Time
Alongside your needles, you should have a suitable sharps container for disposing of used needles safely. Used needles should not be placed in household waste or recycling. Ask your pharmacy, GP practice or local council about the sharps disposal arrangements available in your area, as these services can vary locally.
Having a sharps container ready when you buy your needles means you have somewhere suitable to dispose of used needles from your first injection. When the sharps container is full, follow your local arrangements for returning or collecting it. Dispose of used needles in the sharps container and follow local guidance for disposing of the finished pen.
A Quick Single Pen Checklist
To have everything ready for one pen:
- At least four compatible pen needles, with a spare or two if you wish.
- A sharps bin for safe disposal.
- Your patient information leaflet and Instructions for Use, which explain the injection and priming steps.
With these items ready, you have the basic supplies needed for the four weekly injections from your pen. Check your needle supply before each injection and obtain more compatible needles when needed.
