How to Inject Mounjaro: Video Walkthrough and Technique Guide

The myth worth correcting first: self-injection is not as hard as it looks

A lot of people search for a video on how to inject Mounjaro because they have never given themselves an injection before and assume the process is complicated. It is not. The KwikPen is designed so that you do not see the needle go in — once the pen is pressed against the skin and the button is pressed, the injection happens automatically. There is no plunger to push, no depth to judge. What the video guide shows is that the main job of the person injecting is simply to hold the pen steady against the skin until the dose-confirmation window turns green.

That said, technique still matters. Rushing the pen away before the window confirms the dose is the most common mistake our prescribers see — and it means you may not receive the full dose. Hold the pen flat and still against the skin for the full count (the leaflet specifies exactly how long), wait for the green indicator, then lift. That single habit removes most of the injection errors that get reported.

For a more detailed visual walkthrough, the pen injection video guide on this site covers each step in close-up.

Preparing for the injection: the steps that happen before the pen touches skin

Preparation takes longer than the injection itself, and it is where most of the important decisions happen. Start by taking the pen from the fridge around 30 minutes before you plan to inject; a cold pen is more likely to cause stinging at the site. While it comes to room temperature, wash your hands thoroughly.

Choose your injection site for this week (abdomen, thigh, or upper arm) picking a spot at least a couple of centimetres away from last week's site. Clean the area with an alcohol swab and let it dry completely before proceeding; injecting through wet skin can sting. Attach a fresh needle to the pen. Check the inspection window: the liquid should be clear or faintly yellow, with no particles. If it looks cloudy or discoloured, do not use that dose and contact your prescriber.

Never inject into skin that is bruised, tender, or has active scar tissue. The abdomen is the most popular site for most people because it is easy to reach, though some find the thigh more comfortable when sitting.

Injecting, disposing and what to do if something seems wrong

Press the pen firmly against the cleaned skin, enough pressure to create a small indent but not so hard that it distorts the tissue. Press the injection button and keep the pen in place. The green confirmation window is your cue that the dose has been delivered. Lift the pen cleanly away from the skin; the needle retracts automatically.

Dispose of the used pen immediately into a dedicated sharps container. Standard household bins are not safe for used needles, and most community pharmacies accept full sharps containers for disposal.

A small amount of redness or a minor lump at the injection site is common and usually settles within a day or two. If you notice persistent swelling, pain that worsens rather than fades, or any sign of allergic reaction, contact your prescriber or seek medical advice. The NHS tirzepatide medicines page lists the full range of side effects and which ones need urgent attention.

For questions around storage specifically (including what happens if the pen has been out of the fridge longer than intended) the page on Mounjaro and fridge storage has the detail. And if you want a broader overview of the treatment itself, the Mounjaro treatment guide covers how it works, eligibility, and what to expect across the dose schedule.

Timing, routine and keeping track of your weekly dose

Mounjaro is injected once a week, on the same day each week. Picking a day that fits a consistent routine makes it easier to remember, some people tie it to a specific evening, others to a weekend morning before the day gets busy. It does not have to be timed around food.

If you miss a dose, the Patient Information Leaflet sets out exactly what to do depending on how much time has passed before your next scheduled injection. Do not double up. Your prescriber is the right person to contact if you are unsure, not a forum.

Switching from a video on how to inject Mounjaro to actually doing it confidently usually only takes one or two injections. Most patients tell our team that by the third week it feels routine. The Mounjaro use video and the full injection walkthrough are there to revisit whenever you need a visual reminder.

For context on cost if you are still weighing up whether to start treatment, the treatment overview page sets out what is included at nume and how the process works. The Mounjaro SmPC on the eMC contains the full prescribing information, including the exact injection duration, storage limits and contraindications, and is worth bookmarking alongside any video guide you use.

If you have not yet started Mounjaro and want to find out whether it is clinically suitable for you, speak to our prescribers, a named clinician reviews every consultation the same day.