How to Use the Mounjaro KwikPen: Step-by-Step Injection Guide

When you receive your Mounjaro from a UK pharmacy, the packaging will contain the Mounjaro KwikPen, which is a pre-filled, single-dose disposable injector device. Each box contains 4 KwikPens, providing one month's supply (one injection per week). The pen comes with the needle already built in and hidden inside the device, so you never see or handle a separate needle. Each pen is colour-coded by dose to prevent confusion:

• 2.5mg: Purple
• 5mg: Brown
• 7.5mg: Green
• 10mg: Dark blue
• 12.5mg: Red
• 15mg: Grey

Before your first use, check that the pen matches your prescribed dose, the expiry date has not passed, and the medication visible through the inspection window is clear and colourless to slightly yellow. Do not use the pen if the liquid appears cloudy, discoloured, or contains particles. If anything looks wrong, contact your pharmacy before using it.

Proper preparation makes the injection more comfortable and ensures the full dose is delivered correctly.

• Remove the pen from the fridge 30 minutes before injecting. Injecting cold medication can be more uncomfortable. Let the pen reach room temperature naturally. Do not use a microwave, hot water, or any other heat source to warm it.
• Wash your hands thoroughly with soap and water.
• Choose your injection site. The three approved sites are: the abdomen (at least 5cm away from the belly button), the front of the thigh (middle third), or the back of the upper arm (only if someone else is administering the injection). Rotate your injection site each week.
• Clean the injection site with an alcohol wipe or swab. Allow the skin to dry completely before injecting. Injecting into wet skin can sting.
• Check the pen. Look at the inspection window on the side of the pen. The liquid should be clear. Remove the grey base cap by pulling it straight off. You will see the locked needle underneath. Do not touch the needle area.

If you are anxious about self-injecting, this is completely normal. Many users report that the first injection is the most daunting, and it becomes routine very quickly. The KwikPen needle is very fine (similar to an insulin pen needle), and most users describe the sensation as a brief, mild pinch.

Follow these steps carefully for each injection:

• Step 1: Remove the grey base cap by pulling it straight off. Set it aside. You will not need to replace it.
• Step 2: Place the clear base flat against your cleaned skin at the chosen injection site. You do not need to pinch the skin unless you are very lean. The pen should be held at a 90-degree angle to your skin.
• Step 3: Unlock the pen by turning the lock ring from the locked to the unlocked position. You will feel a click.
• Step 4: Press and hold the purple injection button on top of the pen. You will hear a loud click as the needle inserts and the injection begins. Keep the pen pressed firmly against your skin.
• Step 5: Continue holding the pen against your skin. The injection takes approximately 5-10 seconds. You will hear a second click when the injection is complete.
• Step 6: After the second click, keep holding the pen against your skin for an additional 5 seconds to ensure the full dose has been delivered.
• Step 7: Slowly lift the pen away from your skin. The needle will automatically retract back into the pen. If you see a small drop of blood or liquid at the injection site, apply gentle pressure with a cotton pad for a few seconds. Do not rub the site.

The grey plunger visible through the inspection window should now be at the bottom, confirming the full dose was delivered. If it has not moved to the bottom, the full dose may not have been administered. Contact your prescriber or pharmacy for advice.

Rotating your injection site is important to prevent skin irritation, lipodystrophy (changes in fat tissue under the skin), and injection site reactions.

• Rotate between different areas: Alternate between abdomen, left thigh, and right thigh on a weekly rotation. If someone helps you inject into your upper arm, include that in the rotation as well.
• Within each area, vary the exact spot: Do not inject in the same precise location each time. Move at least 2-3cm from the previous injection point within the same general area.
• Avoid injecting into scar tissue, moles, bruises, or stretch marks as absorption may be affected.

Tips for a more comfortable injection:

• Room temperature medication: Always allow the pen to warm to room temperature. This is the single most effective way to reduce discomfort.
• Relax the muscle: Tension in the muscle makes injections more painful. Take a slow breath and relax the area before pressing the button.
• Apply an ice cube to the injection site for 30-60 seconds beforehand. This numbs the area slightly and can reduce the sensation of the needle.
• Inject at the same time each week: While not strictly necessary for effectiveness, a consistent routine makes it easier to remember and can reduce anxiety around the process.
• Distract yourself: Watch television, listen to a podcast, or have a conversation while injecting. Looking away from the injection site can help if you are needle-averse.

Correct storage ensures your medication remains safe and effective. Unopened pens (not yet used): Store in the refrigerator at 2-8 degrees Celsius. Keep pens in the original carton to protect from light. Do not freeze. If a pen has been accidentally frozen, do not use it. Pens can be stored in the fridge until the expiry date printed on the packaging. Room temperature storage: If needed, unopened pens can be stored at room temperature (up to 30 degrees Celsius) for a maximum of 30 days. After 30 days at room temperature, the pen must be discarded even if unused. Write the date you removed it from the fridge on the carton so you can track this. Practical storage tips: Do not store pens in the fridge door, as the temperature fluctuates more there. The middle shelf is ideal. Keep pens away from the back wall of the fridge where freezing can occur. When travelling, use an insulated cool bag with a cold pack (not in direct contact with the pen) to maintain the correct temperature. If you receive your Mounjaro by post, check that the cold-chain packaging is still cool on arrival. Most UK pharmacies use validated cold-chain delivery to ensure the medication arrives at the correct temperature.

Used Mounjaro KwikPens contain a retracted needle and must be disposed of safely. In the UK, you should never place used pens in household waste or recycling bins.

• Use a sharps bin: Place used pens in a yellow sharps disposal container. Many pharmacies include a sharps bin with your order, or you can request one from your local pharmacy or GP surgery at no charge.
• Seal the bin when full: When your sharps bin is approximately three-quarters full, seal it using the built-in locking mechanism.
• Return to a pharmacy or council collection: Most UK pharmacies will accept full sharps bins for safe disposal. Alternatively, some local councils offer sharps bin collection services. Check your council website for details.
• Never attempt to remove the needle from a used KwikPen. The automatic retraction mechanism is designed to keep the needle safely contained.
• Do not reuse pens: Each KwikPen is for a single injection only. Even if it appears that there is remaining medication, the pen cannot deliver a second dose reliably.

Proper disposal protects you, your family, waste collection workers, and the environment. If your pharmacy does not provide a sharps bin, ask them to supply one or contact your GP surgery. You are entitled to a sharps bin free of charge through the NHS. For information on Mounjaro doses and titration, see our dosing guide. To compare prices across UK pharmacies, visit our price comparison page.