Starting a medicated weight loss journey can be life-changing, but it is entirely natural to feel a little nervous about managing the medication yourself at home.
In the UK, Mounjaro (tirzepatide) is delivered using a multi-dose injection device called the KwikPen.
The KwikPen is designed to be highly intuitive, safe, and straightforward to use once you know the steps.
However, because it contains a full month’s worth of medication (four individual weekly doses), understanding exactly how to store, prepare, inject, and safely dispose of your pen is essential to protect the efficacy of the medicine and keep yourself safe.
At McMinns Pharmacy in Wishaw, we talk through the mechanics of the KwikPen with every single patient who joins our clinician-led Medicated Weight Loss Clinic.
To give you total confidence between your clinic check-ins, we have put together this definitive, step-by-step guide to mastering your Mounjaro KwikPen.
Before You Start: Understanding Your KwikPen
Your Mounjaro KwikPen comes as a pre-filled device that holds four full doses.
You will use the exact same pen once a week for four consecutive weeks. However, you will need a brand-new, sterile pen needle for every single injection.
Before starting, it helps to familiarise yourself with the basic anatomy of the pen, as highlighted in the diagram above:
- The Dose Window: This displays numbers (0 when starting, 1 when dialed).
- The Dose Knob: The purple or colored end piece that you twist to set your dose and press down to inject.
- The Cartridge: The transparent middle barrel containing the liquid medicine.
Temperature Control and Storage
The hormones inside Mounjaro are delicate biological proteins.
If they get too hot, too cold, or are exposed to direct sunlight, they will break down and become completely ineffective.
Storing Unused KwikPens
Keep any brand-new, unused KwikPens in their original cardboard boxes inside the refrigerator at a temperature between 2°C and 8°C.
Store them on a middle shelf – never right at the back or in the freezer box. If a pen accidentally freezes, it must be thrown away immediately.
Storing Your In-Use KwikPen
Once you pierce the pen for your very first injection, it is officially “in use.” From this exact moment, you can choose to keep it in the fridge or store it at room temperature (up to 30°C), away from direct sunlight and heat sources like radiators.
The 30-Day Expiry Rule: An in-use Mounjaro KwikPen is only stable for a maximum of 30 days. Once 30 days have passed, any remaining liquid in the pen must be discarded, even if there is still fluid left inside.
Always store your pen with the protective plastic pen cap securely attached to shield it from light.
The Step-by-Step Injection Guide
Choose a consistent day of the week and a time that works best for you. Wash your hands thoroughly with soap and water, and find a clean, flat surface to lay out your supplies: your KwikPen, a fresh needle, an alcohol wipe (optional), and your sharps bin.
Inspect the medication:
Pull off the large outer plastic pen cap. Look closely at the liquid inside the clear cartridge. The medicine should look completely clear and colorless or slightly yellowish. If it looks cloudy, has changed color, or has visible particles floating inside, do not use it. Instead, bring it back to McMinns Pharmacy for us to check.
Attach a new needle:
Take a fresh pen needle and peel off the protective paper tab. Push the needle straight onto the end of the pen and twist it firmly clockwise until it is tight. Pull off the large outer needle shield (save this for later) and then pull off the thin inner needle shield (throw this away).
Prime the pen (First Use Only):
You only need to do this step the very first time you open a new pen. Slowly turn the dose knob clockwise until you see the small line symbol (looks like a tiny hook or droplet) line up in the dose window. Hold the pen pointing straight up and firmly press the dose knob all the way in. A few drops of liquid should squirt or drip from the tip. This clears any air bubbles out of the cartridge. The window will return to 0.
Dial your full dose:
Turn the dose knob clockwise until it stops and the number 1 is perfectly centered in the dose window. This indicates that one full, therapeutic dose is locked and ready to be delivered.
Choose your injection site:
Mounjaro is injected subcutaneously, meaning into the layer of fat just beneath the skin. Choose from your abdomen (at least 5cm away from your belly button) or the front of your thighs. If someone else is administering the dose for you, the outer back of the upper arm can also be used. Clean the skin if necessary and let it air dry.
Inject the medicine:
Insert the needle straight into your skin at a 90-degree angle. Place your thumb firmly on the dose knob and press it all the way down until it clicks and the dose window returns to 0. Hold the needle completely still inside your skin for a slow count of 5 to ensure the full dose has entirely emptied from the pen before pulling it out.
Disposing of Your Needles and Pens Safely
You must never throw loose needles or used medical devices into your household waste bin.
Doing so puts family members, waste collectors, and the public at serious risk of accidental needle-stick injuries.
Safe Needle Removal
Immediately after pulling the needle out of your skin, carefully push the large outer needle shield back over the needle. Twist the needle counter-clockwise to unscrew it from the pen.
Drop the shielded needle straight into your yellow Sharps Bin.
Never leave the needle attached to the pen between doses. Leaving it attached allows air into the cartridge, causes the medication to leak out, and drastically increases the risk of bacterial contamination.
Where to Get and Dispose of Your Sharps Bin
When you pick up your initial weight loss treatment from McMinns Pharmacy, our clinicians will issue you a dedicated, puncture-proof yellow sharps container.
In Wishaw and the surrounding area, you can arrange clinical waste collections with the local council.
Once your sharps container is full up to the line indicated on the lid, close the permanent locking mechanism safely.
Once you have used all four doses of your KwikPen, the empty plastic pen shell can be placed into your household waste container, provided the needle has been safely detached and placed in the sharps bin.
Expert Support at McMinns Pharmacy in Wishaw
Using an injectable medication can feel daunting at first, but with a little practice, it quickly becomes an easy habit that takes less than two minutes out of your week.
If you are a resident in Wishaw or the surrounding area and are considering Mounjaro, or if you simply want someone to physically walk you through your first injection, our team is always here to support you.
We provide face-to-face coaching, routine health checks, and a continuous supply of needles and sharps disposal units to ensure your journey is safe and seamless.
Ready to take control of your weight management goals with professional clinical guidance? Book a private consultation online or visit us in-store today.