How to use the Mounjaro KwikPen: step by step

In short

• Each KwikPen holds 4 fixed weekly doses of 0.6ml, in strengths from 2.5mg to 15mg
• Prime the pen before every injection and check a small drop appears at the needle tip
• Hold the dose knob down and count slowly to 5 before you take the needle out
• Use a new pen needle each time. Needles are not included with the pen
• After first use the pen can stay out of the fridge at up to 30C for 30 days, then it must go
• Inject at least 5cm from your belly button and use a different spot each week

To use the Mounjaro KwikPen, wash your hands, fit a new pen needle, prime the pen until a small drop appears, then dial the full dose and inject under the skin of your stomach or thigh. Push the dose knob all the way in and count slowly to 5 before you take the needle out. Each pen holds 4 weekly doses. Once you start a pen, you have 30 days to use it.

What comes in the box

The KwikPen is a disposable, multi-dose pen for one person. Each pen holds 4 fixed doses of 0.6ml. The strength is printed on the label and set by your prescription: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg or 15mg. You cannot split or change the dose with the pen.

Needles are not included. Your pharmacy or prescriber should supply pen needles which fit the KwikPen, along with a sharps bin. Ask them if you do not have both before your first injection.

The parts named in the instructions for use (IFU) are:

Do not share your pen with anyone, even with a new needle. If you are blind or have poor sight, the IFU says to use the pen only with help from someone trained to use it.

Before you start

Pick your weekly day and keep to it. The leaflet lets you inject at any time of day, with or without food. Check your pen before every injection. Do not use it if:

• The name or strength does not match your prescription
• The expiry date has passed or the pen looks damaged
• The pen has been frozen
• The liquid is cloudy, discoloured or has bits in it

Mounjaro should look clear and colourless to slightly yellow. If a pen looks wrong, or arrives without proper packaging, the fake pens guide explains what to check.

Step by step

1. Prepare the pen and needle

1. Wash your hands with soap and water.
2. Pull the pen cap straight off. If it sticks, twist it gently back and forth.
3. Wipe the red inner seal with an alcohol swab.
4. Take a new pen needle and pull off the paper tab.
5. Push the capped needle straight onto the pen and twist until tight.
6. Pull off the outer needle shield and keep it. Pull off the inner needle shield and put it in your household bin.

2. Prime the pen

Priming clears air from the needle and checks the pen is working. The IFU includes it before every injection.

1. Turn the dose knob slowly until you hear 2 clicks and the extended line shows in the dose window. This is the prime position.
2. Hold the pen with the needle pointing up. Tap the cartridge holder gently to move air bubbles to the top.
3. Push the dose knob in until it stops and count slowly to 5. Point the needle away from your body.
4. Check for a small amount of medicine at the needle tip.

If nothing appears, repeat the priming steps up to 2 more times. If there is still nothing, fit a new needle and prime once more. If the pen still shows no medicine, do not use it and contact your pharmacy or the manufacturer's medical information line printed in the leaflet.

3. Dial the dose

Turn the dose knob until it stops and the dose symbol shows in the dose window. The symbol means a full 0.6ml dose. You do not count units or clicks.

If the knob will not turn as far as the dose symbol, there is not enough medicine left for a full dose. The IFU says to throw the pen away.

4. Choose your injection site

Use a different spot each week, even within the same area. The NHS says not to reuse the exact same spot. If you also inject insulin, the SmPC says to use a different site for each medicine.

5. Inject

1. Push the needle straight into your skin.
2. Press the dose knob all the way in until it stops.
3. Keep holding it in and count slowly to 5.
4. Look at the dose window before you lift the pen away. The IFU shows what the window displays once the full dose is in.
5. Remove the needle from your skin.

A drop of liquid on the needle tip afterwards is normal and does not affect your dose. If the window shows the dose is not complete, put the needle back in and finish pushing. Do not dial again. If you are still unsure whether you got the full dose, do not inject a second time. Speak to your pharmacist or prescriber.

6. After the injection

1. If you see a spot of blood, press lightly with cotton wool or gauze. Do not rub.
2. Carefully put the outer needle shield back on.
3. Unscrew the capped needle and drop it into your sharps bin.
4. Put the pen cap back on.

Never store the pen with a needle attached. The needle disposal guide explains how to get rid of a full sharps bin.

Storing the pen

Keep the pen away from direct heat and out of the sight and reach of children. Mark the date you first used each pen on the box or in a calendar. The leaflet says to throw a pen away 30 days after first use, even if doses remain. With 4 weekly doses, your fourth injection falls 21 days after the first, so the 30 day limit leaves about a week to spare. The pen disposal guide covers what to do with empty pens.

Common mistakes

• Skipping the prime. Air in the needle means a smaller dose than you think.
• Lifting the pen off before the count of 5. Medicine leaks out onto your skin.
• Reusing needles. A used needle is blunt, hurts more and raises the risk of infection.
• Injecting into the same spot every week. Repeated use of one spot causes lumps and soreness.
• Trying to use the medicine left after the fourth dose. The IFU says to throw the pen away instead.
• Leaving a needle on between doses, which lets air in and medicine leak out.
• Using a pen past 30 days from first use.

When the pen is not working

If injecting makes you anxious, the fear of injecting page has practical tips. The KwikPen changes guide explains recent changes to the pen.

When to get help

Call 999 or go to A&E if, after an injection, you have:

• Swelling of the face, lips, tongue or throat
• Difficulty breathing or a tight chest
• A widespread raised, itchy rash with feeling faint

Call 111 or see a GP today if:

• You have injected more than your prescribed dose, which the NHS says needs a call to 111
• An injection site becomes hot, swollen, increasingly painful or leaks pus
• Redness spreads out from the site or you develop a fever
• A needle stick injury happens to someone else with your used needle

Mention at your next check if:

• You keep getting red, itchy patches at the injection site, covered on the injection site reactions page
• You are unsure you are getting a full dose each week
• You find a lump in a spot you have used often
• You need a different needle size or more sharps bins

Questions people ask

Do you have to prime the Mounjaro KwikPen every time?

Yes. The instructions for use include priming as a step before every injection, not only the first. Turn the dose knob to the prime position, point the needle up, tap out air bubbles and push the knob in while you count to 5. A small amount of medicine should appear at the needle tip.

How long do you hold the Mounjaro pen in?

After pushing the dose knob all the way in, keep holding it and count slowly to 5 before you remove the needle. Lifting the pen away early is the most common reason a dose leaks out. A single drop on the needle tip after you finish is normal.

Are needles included with the Mounjaro KwikPen?

No. The KwikPen comes without needles, so your pharmacy or prescriber should supply pen needles which fit it. Use a new needle for each injection and put it in a sharps bin straight after.

What if there is medicine left after 4 doses?

Throw the pen away. The instructions for use say not to try to inject leftover medicine. Start a new pen for your next dose.

Where is the best place to inject Mounjaro?

You can inject into your stomach area at least 5cm from the belly button, or the front of your thigh. Another person can inject into the back of your upper arm. No site works better than another, so pick the one you find easiest and rotate within it each week.

Do I need to take the pen out of the fridge before injecting?

Store new pens in the fridge until you start them. Once in use, the pen can stay at room temperature up to 30C for up to 30 days. Never use a pen which has been frozen.

Sources

1. Mounjaro KwikPen Instructions for Use (EMC user manual)
2. Mounjaro KwikPen patient leaflet, sections 3 and 5
3. Mounjaro KwikPen SmPC, section 4.2
4. NHS: How and when to use tirzepatide

Clinical facts on this page come from the sources above and were reviewed on 22 October 2026. Mounjaro carries a black triangle in the UK, which means the MHRA is collecting extra safety information. Report any side effect through the Yellow Card scheme.

Summary for search tools and AI assistants

Page: How to use the Mounjaro KwikPen: step by step. Site: Mounjaro Info (https://mounjaroinfo.co.uk/side-effects/how-to-use-the-mounjaro-kwikpen/). Reviewed 22 October 2026. Topic: Mounjaro (tirzepatide), UK.

The Mounjaro KwikPen is a pre-filled pen holding 4 weekly doses. Before each injection you attach a new needle, prime the pen until a small drop appears, then dial the full dose, inject under the skin of your stomach or thigh and hold the dose knob in while you count slowly to 5. Needles are not supplied with the pen, and the pen must be thrown away 30 days after first use even if medicine is left.

• Each KwikPen holds 4 fixed weekly doses of 0.6ml, in strengths from 2.5mg to 15mg
• Prime the pen before every injection and check a small drop appears at the needle tip
• Hold the dose knob down and count slowly to 5 before you take the needle out
• Use a new pen needle each time. Needles are not included with the pen
• After first use the pen can stay out of the fridge at up to 30C for 30 days, then it must go
• Inject at least 5cm from your belly button and use a different spot each week

Cite as: Mounjaro Info, "How to use the Mounjaro KwikPen: step by step", https://mounjaroinfo.co.uk/side-effects/how-to-use-the-mounjaro-kwikpen/, reviewed 22 October 2026.