Where to Inject Mounjaro in the Abdomen (October 2026)

01 · The core answer

Where on the abdomen should you inject Mounjaro?

Inject into the stomach area, keeping clear of the belly button. Licensed injection sites are the stomach area (at least 5cm from the belly button), the front of the thigh, or the back of the upper arm if someone else gives the injection.¹¹³

In practice, think of the lower and side parts of the stomach: the soft area below the waist on the left and the right, with a generous gap around the navel. That gap is the part people most often ask about. The licence gives a minimum distance, so stay beyond it rather than testing the edge. If you are unsure whether a spot is far enough away, move further out.

For a visual walk-through, see our picture guide to injection sites. For the stomach on its own, our page on injecting into the stomach covers the same ground from a different angle.

02 · Choosing a site

Stomach, thigh or arm: which should you pick?

Many people default to the stomach because they can see what they are doing.

If you are wondering whether the choice changes how well the medicine works, our page on whether it makes a difference where you inject goes through it. All three sites are licensed, so choose on comfort and consistency.

03 · Rotating your site

How to rotate your abdomen injection site

Rotate the site with each dose. That is the licensed instruction, and it is the single habit that keeps the skin in good condition over months of treatment.¹¹³

A simple system works well. Imagine the lower stomach divided into a left side and a right side. Use the right side one week and the left the next. Within each side, shift the spot slightly each time rather than returning to exactly the same place. You can use the stomach again the following week, as long as the new spot is clearly away from the last one.

Some people keep a note on their phone, or use our free GLPTrackr companion app, to record which side they used. Because the pen is a weekly injection, it is easy to forget which side you used last time.

If you want to alternate between the abdomen and the thigh, that is within the licence too. Just keep the same day each week and rotate within whichever area you choose.

04 · Skin to avoid

Which areas of the stomach to avoid

Stay away from the area immediately around the belly button, and avoid any patch of skin that looks or feels abnormal.

Beyond that, use ordinary common sense and the patient information leaflet. Skip skin that is bruised, tender, red, hard, scarred or otherwise damaged, and choose a different spot or a different site instead. Also avoid injecting through clothing or into places where a waistband rubs, because irritated skin makes the next injection more uncomfortable.

We have a dedicated page on where not to inject Mounjaro if you want the full list in one place.

If a particular spot is persistently sore, lumpy or changes colour, tell your prescriber or pharmacist. Do not simply keep injecting there.

05 · Too close to the navel

What happens if you inject too close to the belly button?

If you inject too close to the belly button, do not take an extra dose to compensate, and do not repeat the injection.

If it happens once, make a note of it, use a spot well clear of the navel next week, and mention it if you speak to your prescriber. If you have any new symptom afterwards, such as pain, swelling or a reaction at the site, contact your pharmacy or prescriber for advice. If you have severe, persistent stomach pain that may spread to your back, with or without vomiting, get medical help straight away. You can also report suspected side effects through the MHRA Yellow Card scheme.¹⁹

The practical fix is prevention. Before you press the pen to your skin, look at where it is relative to your navel. If there is any doubt, move outwards.

06 · Pen set-up and dose

Setting the pen before you inject

Choose your site only after the pen is correctly set, because the dose matters more than the position. The KwikPen is set by turning the dose knob until the dose indicator shows the correct dose in the window.

Each KwikPen contains four weekly doses.

For exact steps on needle handling, skin technique and what to do after the injection, follow the instructions that come with the pen and the patient information leaflet. Needles, a sharps bin and injection guidance are included with every order from us.

07 · Pinching and angle

Do you pinch the skin, and at what angle?

Whether to pinch is a technique question that the pen's own instructions answer, so follow the leaflet supplied with your pen rather than a tip from a forum.

The same applies to angle. The KwikPen is designed to be used the way its instructions show, and our page on what angle to inject Mounjaro explains how to approach it. If you have very little fatty tissue on your abdomen, or you feel unsure, ask your prescriber or pharmacist to talk you through it. A short conversation is better than guessing.

Medicine is injected under the skin, not into muscle and not into a vein. That is why the site and technique guidance matters.

08 · Injecting it wrong

Is it possible to inject Mounjaro wrong?

Yes, you can make a mistake, but most mistakes are minor and fixable through simple steps. Typical slips include injecting too close to the navel, forgetting to rotate, or being unsure whether the full dose went in.

If you are unsure whether you received the dose, do not repeat it on the spot. Contact your prescriber or pharmacy and describe what happened. The missed-dose rule also stays the same: if you miss a dose, take it as soon as you can within 4 days (96 hours) of the scheduled time, then carry on with your usual day. If more than 4 days have passed, skip the missed dose entirely and take the next one on your normal day, and never take two doses within 3 days of each other.¹

Do not change the dose or try to split or stretch what is in the pen. Altering doses outside the licence means unknown dosing accuracy and no safety data.¹ If anything feels wrong afterwards, speak to a professional and report it through Yellow Card.¹⁹

09 · Day, time and storage

Choosing your day and storing the pen

There is no best time of day: Mounjaro works the same morning or evening, with or without food. What matters is the same day each week. Many people choose a weekend morning so early side effects fall on days off.¹

You can change your weekly injection day if needed, as long as at least 3 days (72 hours) have passed since your last dose.¹

Keep Mounjaro pens in a fridge at 2–8°C and never freeze them. Once in use, a pen can be kept out of the fridge not above 30°C for up to 30 days, after which it should be discarded. Keep the pen cap on to protect it from light, and never use a pen that has been frozen.¹¹³

The pen's instructions are the place to check whether you should let it reach room temperature before use.

10 · Who gives the injection

Is it better to inject in the arm or the stomach?

For most people the stomach is the more practical choice, because the arm is licensed only if someone else gives the injection.

If a partner, relative or carer helps, they should read the pen's instructions first and use the same rotation approach. Make sure they know the distance rule for the stomach too, in case you switch sites.

If you are unsure which site suits you, compare the options in our overview of where to inject Mounjaro and how the sites compare.

11 · Starting treatment

Starting treatment and getting support

Everyone starts Mounjaro on 2.5mg once a week. This starting dose is about letting your body adjust, not about weight loss itself.¹ It is also the dose at which you learn the routine, so take your time over site choice and rotation in those early weeks.

If you order from us, a GPhC-registered prescriber reviews your free online consultation, and our team offers side-effect support and ongoing monthly reviews. Delivery is free, next-day and tracked in temperature-controlled packaging, and we supply genuine pens through official LillyDirect supply. You can read more about our weight loss clinic and what each stage involves.

Support is available Monday to Friday, 9am to 5pm, by email at support@everydaymeds.co.uk or by phone on 0333 207 0413. Mounjaro is a prescription-only medicine used alongside a reduced-calorie diet and increased physical activity, and individual results vary.