Mounjaro uses a pre-filled, single-use device called the KwikPen. The needle is already attached and hidden inside the device, making it suitable even for people who are nervous about needles. Here's how to use it correctly.
Before You Begin
Gather what you need:
- Your Mounjaro KwikPen (check the colour matches your prescribed dose)
- An alcohol swab or clean tissue
- A sharps disposal bin (available free from most UK pharmacies)
Take the pen out of the fridge 30 minutes before injecting to allow it to reach room temperature. Injecting cold medication can be more uncomfortable. Do not microwave or heat the pen.
Step 1: Inspect the Pen
Check the expiry date on the label. Look through the inspection window — the liquid should be clear, colourless to slightly yellow, and free of particles. If it appears cloudy, discoloured, or contains visible particles, do not use it and contact your pharmacy.
Step 2: Choose Your Injection Site
You can inject Mounjaro into three areas:
- Abdomen (at least 5 cm from the navel)
- Front of thigh
- Back of upper arm (you may need help with this site)
Rotate your injection site each week. Don't inject into the same spot repeatedly, as this can cause skin changes over time.
Step 3: Prepare the Site
Clean the injection area with an alcohol swab and allow it to dry completely. Do not blow on the area to speed drying. Avoid injecting into skin that is bruised, tender, hard, or scarred.
Step 4: Unlock and Inject
- Pull off the grey base cap — you'll hear a click
- Place the clear base flat and firmly against your cleaned skin
- Press and hold the purple injection button — you'll hear a first click indicating the injection has started
- Continue holding the pen against your skin
- Wait for the second click — this means the injection is complete
- After the second click, slowly count to 10 while keeping the pen pressed against your skin
- Remove the pen
Step 5: After the Injection
You may see a small drop of blood or liquid at the injection site — this is normal. Press gently with a clean tissue if needed. Do not rub the area. Dispose of the used pen in your sharps bin immediately. Never recap or reuse a pen.
Common Mistakes to Avoid
- Removing the pen too quickly before the second click
- Not holding the pen firmly enough against the skin
- Injecting through clothing
- Using a pen that has been frozen (even if thawed, it must be discarded)
Disposing of Used Pens
Used KwikPens should go in a yellow sharps bin. You can get these free from your GP surgery or local pharmacy. When full, return the bin to your pharmacy for safe disposal — this is a free NHS service across the UK.