How to Administer Mounjaro: What You Need to Know

Mounjaro (tirzepatide) is injected subcutaneously — meaning just under the skin — once a week. According to the electronic Medicines Compendium (eMC) product information, the recommended injection sites are the abdomen, thigh, or upper arm. A few practical points apply to all three:

• Rotate sites with every injection. Using the same spot repeatedly can cause lumps or changes in the skin (lipohypertrophy) that may affect how well the medicine is absorbed. Move to a different area, or at least a different spot within the same area, each week.
• Avoid broken, bruised, or irritated skin. Also avoid injecting into the navel or any scarred tissue. If you notice persistent redness, swelling, or a lump at an injection site, mention it to your prescriber or doctor.
• The KwikPen is single-use. Each Mounjaro KwikPen is designed for one injection only. Check the label on your pen matches the dose your prescriber has directed, and always follow the instructions in the patient information leaflet (PIL) that came with your medication.
• Temperature matters. Pens should be stored in a refrigerator until use. Check your PIL for exact guidance, but typically a pen can be kept at room temperature for a limited period before use — your leaflet or a registered pharmacist will confirm the specifics for your supply.

If you have any questions about technique — the angle to hold the pen, how long to keep it in place, or how to handle a pen that looks unusual — your prescriber, doctor, or pharmacist is the right person to ask. For a visual walkthrough, you may also find a Mounjaro administration video guide useful alongside your PIL.

For broader context on Mounjaro and how it works, visit our Mounjaro overview hub.

Keeping a clear record of every dose — when you injected, which site you used, and how the area felt afterwards — turns what can feel like a lot to remember into something simple and searchable.

GLP Trackr's injection-site tracking and rotation feature is built exactly for this. Each time you log a shot, you record the site you used (abdomen, thigh, or upper arm), and the app tracks your rotation history so it can suggest which site to use next. Over weeks of treatment, that record becomes a genuinely useful reference — both for staying consistent and for flagging any patterns (such as a site that keeps reacting) to discuss at your next prescriber appointment.

Alongside site logging, dose reminders mean your weekly injection day doesn't slip past unnoticed — especially useful during the early weeks when the routine is still new. You can also log side effects such as injection-site redness or nausea directly in the app, so nothing is forgotten before an appointment.

If you are curious about how people typically start their Mounjaro journey or how Mounjaro is generally obtained, those pages cover the wider context. For information on Wegovy and how Wegovy is prescribed and accessed, that guide is available too.

Any concerns about your injection technique, a site reaction, or your dose should always go to your prescriber or doctor — they know your full history and are best placed to advise. GLP Trackr helps you record what's happening so those conversations are informed and specific, not a substitute for them.

Ready to take the guesswork out of rotation? GLP Trackr is free to try for 7 days — download it on the App Store or Google Play and let the app handle your injection history from your very first log.