Injection sites and rotation: what the leaflets say

Where you inject is one of the few things both leaflets describe in almost the same words. This article sets out what each one says, and how the injection site map in the Dose Club app records it.

The Wegovy leaflet

The UK Wegovy leaflet says: "The best places to give the injection are the upper arms, stomach or upper legs. You may inject in the same body area, but make sure it is not in the same spot as used the last time." It also says the medicine is injected under the skin and must not be injected into a vein or muscle, and that a new needle is used for each injection.

The Mounjaro leaflet

The UK Mounjaro leaflet says the medicine is injected under the skin of your stomach area (abdomen) or upper leg (thigh) or the back of your upper arm, and that someone else should help if you want to inject in the back of your upper arm. On rotation it says you can use the same area of your body each week, but to be sure to choose a different injection site within that area.

What the two have in common

• Three areas: the stomach, the thigh and the upper arm.
• Under the skin, which the leaflets call a subcutaneous injection.
• A different spot each time, even when you stay in the same area.

The leaflets give the instruction without explaining it. Injection site reactions, such as redness or itching where the needle went in, appear in both leaflets' lists of side effects. If a site becomes sore or you notice a change in the skin, the leaflets' standing advice applies: ask your doctor, pharmacist or nurse.

The pen instructions

The leaflet comes with instructions for use for the pen itself: how to attach a needle where the pen takes one, how to prepare the pen, how to hold it against the skin and how long to keep it there before lifting it away. The instructions give the count for your pen, so follow the ones in your box. If you are unsure about any step, the leaflets say to ask your doctor, pharmacist or nurse, and the pharmacy that dispensed the medicine can go through the steps with you.

The site map in the app

The injection site map in the Dose Club app is a body map. When you log a dose you tap the site you used, and the map builds a history: which areas you have used, which spot you used last and how long it has been since each one. Opening the map before a dose shows where the last few went, so rotation stops depending on memory.

The record is yours. It stays on the device unless you turn on backup and sync in Dose Club Plus, and the dose log, with the site recorded against each dose, goes into the prescriber PDF, so a prescriber or nurse can see the pattern if a site has been giving trouble.

Telling someone about a reaction

A reaction at the injection site that worries you is a question for your prescriber or pharmacist. Both leaflets also ask you to report side effects, including ones not listed, through the MHRA's Yellow Card scheme, which takes reports from patients directly.

Needles and sharps

A used needle goes into a sharps bin, never into household waste. Ask your pharmacy about a sharps bin and how a full one is collected; councils run collection schemes that vary by area, and the community has threads comparing what works locally. Needles and pens with needles attached should not travel loose in a bag.

Sources

• Wegovy patient information leaflet, electronic medicines compendium: medicines.org.uk/emc
• Mounjaro patient information leaflet, electronic medicines compendium: medicines.org.uk/emc
• MHRA Yellow Card scheme: gov.uk

This article is information, not medical advice. Talk to your prescriber about your treatment.