Where's Best to Inject Mounjaro? Sites and Rotation Guide (October 2026)

01 · The short answer

The three licensed Mounjaro injection sites at a glance

Mounjaro is injected under the skin once a week, and the product information lists three sites.¹

Our guide to the best place to inject Mounjaro compares the same choices from a slightly different angle.

02 · Making the choice

How to decide which site is right for you

Start with the site you can reach and see without strain. For most adults injecting alone, that means the stomach area or the front of the thigh. The stomach is at least 5cm from the belly button, which is the measurement the licence gives.¹

If you would like to use the upper arm, plan for another person to do it. The licence only covers the back of the upper arm when someone else injects, so do not try to reach it yourself. If you prefer a particular site, the best spot to inject Mounjaro page covers how people settle into a routine. If you want a body-wide overview, see the best place on the body to inject Mounjaro.

Technique details such as how to hold the pen and how long to keep it in place belong to the pen's own instructions. Follow the patient information leaflet that comes with your KwikPen rather than a rule of thumb you have read elsewhere.¹³ Our how to inject Mounjaro guide walks through the whole routine.

03 · Getting started

Getting your Mounjaro pen from a UK pharmacy

Mounjaro is a prescription-only medicine, so you need an online consultation reviewed by a GPhC-registered prescriber before it can be supplied. You can buy Mounjaro online from us as a GPhC-registered UK pharmacy (registration 9012878). Our genuine KwikPens come through official LillyDirect supply, direct from Eli Lilly's UK distribution, and all six doses are in stock.

Your first 2.5mg pen costs £129.99 with code FIRST40 (standard price £169.99). You can see every dose and today's price on the Mounjaro pen page. Every later order is £25 off the standard price (code DOSE25). Prices checked 27 October 2026.

Ordering works in four steps:

• Free online consultation: a short health questionnaire, with no charge and no obligation. Start your free consultation.
• Prescriber review: a GPhC-registered prescriber reviews your answers. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.
• Dispensing and dispatch: our registered pharmacy dispenses your pen, with same-day dispatch when you order by 3pm.
• Delivery: free next-day tracked delivery in discreet, temperature-controlled packaging. Needles, a sharps bin and injection guidance come with every order.

04 · Stomach injections

Injecting into the stomach area

The stomach area is a licensed site, as long as you stay at least 5cm from the belly button.¹ It is the site many people reach for first because you can see it and reach it without help.

Choose a spot that feels comfortable rather than rushed. If you are injecting for the first time, sit or stand where you can see the area clearly and have the pen, a clean surface and your sharps bin to hand before you start.

Use your pen's leaflet for the step-by-step technique.¹³ If anything about a particular spot worries you, such as skin that looks or feels unusual, ask your prescriber or pharmacist before you inject there. Our where not to inject Mounjaro page covers the areas to avoid in more detail.

The stomach is not the only option. If you feel uncomfortable using it, or you simply want a change, the thigh is the other site you can reach alone.

05 · Thigh injections

Injecting into the front of the thigh

The front of the thigh is a licensed Mounjaro injection site and the usual alternative to the stomach for people injecting alone.¹ The licence names the front of the thigh specifically, so stick to that area rather than other parts of the leg.

Many people find sitting down helps because the thigh is then visible and supported. Rest the pen against your skin as the leaflet instructs and take your time. The thigh and stomach are both licensed sites, so the choice is about comfort and routine.¹

A common pattern is to alternate between sites week by week, which keeps rotation simple. If you want the angle of the pen explained, see what angle to inject Mounjaro.

06 · Upper arm injections

Injecting into the back of the upper arm

The back of the upper arm is licensed only if someone else gives the injection.¹ The upper arm is awkward to see and reach on your own.

If you have a partner, relative or carer who is willing to help, the upper arm is a useful extra option, and it widens the sites you can rotate between. Ask them to read the pen's instructions first so they know how to hold the pen and read the dose window. If you are alone, use the stomach or the front of the thigh instead.

You should never contort your body to reach the back of your own upper arm. A missed or poorly placed injection is a worse outcome than choosing an easier site.

07 · Rotating sites

How to rotate your Mounjaro injection site

The licence says to rotate the site with each dose.¹ Rotation simply means not using exactly the same spot week after week.

Some practical ideas:

• Alternate between stomach and thigh from one week to the next.
• If someone helps you, add the upper arm to the cycle.
• Within the stomach area, move to a different spot each time, staying at least 5cm from the belly button.
• Keep a note on your phone of where you injected last, so you do not have to remember.

You can also use our free GLPTrackr companion app for iOS and Android to track your GLP-1 journey.

08 · Timing and routine

When to inject: day, time and food

There is no best time of day for Mounjaro. It works the same in the morning or evening, with or without food.¹ What matters is injecting on the same day each week.

Choose a day and time you will remember. Many people pick a weekend morning so that early side effects fall on days off. The commonest early effects are mild nausea, altered appetite and tiredness in the first days after each injection, and they usually settle.¹

If you need to change your injection day, you can, as long as at least 3 days (72 hours) have passed since your last dose.¹

The injection site does not change any of this. Whether you use the stomach, thigh or upper arm, the weekly timing rule is the same.

09 · Using the KwikPen

Your Mounjaro dose

Everyone starts on 2.5mg once a week. This is about letting your body adjust rather than weight loss itself. After at least 4 weeks the dose rises to 5mg, and it can then step up by 2.5mg at minimum 4-week intervals up to 15mg, depending on your response and tolerance.¹ Your prescriber guides the pace.

10 · Missed doses

What if you miss a dose or inject late?

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.¹

If more than 4 days have passed, skip the missed dose entirely and take the next one on your normal day. Never take two doses within 3 days of each other.¹

Whichever site you used last time, pick the next in your rotation as normal. Missing a dose does not change the site rule. If you are unsure whether to inject, contact our support team on 0333 207 0413 (Monday to Friday, 9am to 5pm) or email support@everydaymeds.co.uk, or speak to your prescriber.

11 · Storage and travel

Storing your pen and travelling with it

Keep Mounjaro pens in a fridge at 2–8°C and never freeze them.¹ Once a pen is in use, it can be kept out of the fridge not above 30°C for up to 30 days, then it should be discarded. Keep the cap on to protect it from light, and never use a pen that has been frozen.

You can fly with Mounjaro. Carry pens in hand luggage, because hold luggage can fall below freezing, ideally in a cool bag with the prescription label or a copy of your prescription.¹ For hot climates use an insulated pouch, and check the destination's rules for travelling with prescription injectables before you fly.

Unopened pens stay in the fridge and keep until the printed expiry date. If an unopened pen has been out of the fridge, check with the pharmacy before using it rather than relying on a day limit you have seen online.

12 · Other injectables

Injection sites for other weight-loss medicines

Other injectable medicines each have their own leaflet, pen and licensed sites, so do not assume Mounjaro's guidance applies to them.

If you use Ozempic, Wegovy or any other prescribed pen, follow the instructions in that product's patient leaflet and ask your prescriber or pharmacist. We would also urge caution about anyone offering to supply them without a consultation or prescription.

If you notice a new symptom after any injection, discuss it with your prescriber. You can also report suspected side effects through the MHRA Yellow Card scheme.¹⁹ If you are weighing up pens, our where to inject Mounjaro comparison may help, and you can browse all weight loss treatments.

13 · Serious side effects

Serious side effects: when to get help straight away

Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.¹