Mounjaro injection sites: where's best to inject?

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What's the best Mounjaro injection site? Should you change it with each dose? Find out in our quick guide.

A man in a striped shirt and tie is injecting himself with an insulin pen.

Mounjaro is an injectable weight loss medication that comes in a pre-filled KwikPen. This is a pen-shaped device that's designed to make it easy to inject the drug yourself at home.

Most patients get used to injecting themselves quite quickly. However, if you've never done it before, you might feel a little nervous – and you probably have lots of questions.

In this article, we tackle one of the most common: 'Where am I supposed to inject Mounjaro?'

Ready? You might feel a tiny pinch…

What are the possible Mounjaro injection sites?

You can choose any one of these injection sites for Mounjaro:

The soft part of your belly (at least 5cm from your belly button)

The front side of either thigh

The back of either upper arm (if someone else is giving the injection)

These injection sites all have something in common: they contain subcutaneous tissue. This is a fatty layer underneath the skin.

Mounjaro is taken as a subcutaneous injection. In other words, it's injected under the skin into this fatty layer. It doesn't need to be injected directly into a vein.

The good news is that subcutaneous injections are very easy to take. Most people find them relatively painless, too. Bear in mind that we all experience pain differently, though – and some injection sites tend to hurt more than others.

Another reason that Mounjaro is taken as a subcutaneous injection is that it helps the drug work more effectively. Injecting Mounarjo into a fatty layer ensures it's absorbed into the body at the right pace.

A woman is getting an injection in her arm.

What's the best injection site for Mounjaro?

If you're injecting yourself, it's best to do it in your belly or thigh, as these areas are easiest to access. If someone else is giving you the injection, they should do it in the back of your upper arm.

These guidelines aside, it's more or less up to personal preference. Unless your doctor advises

otherwise, you're free to choose between injecting yourself in the belly and injecting yourself in the thigh.

It's worth trying both. You might find that one injection site hurts less than the other – or is simply easier or more comfortable for you.

Should you change the Mounjaro injection site each time you take the medication?

Yes. We recommend that you change the injection site with each weekly dose.

This doesn't mean you have to choose a different part of your body. You can, for instance, always take the injection in your belly. However, if choose to do this, you should inject it into a different part of your belly each week.

Rotating Mounjaro injection sites like this is important because it minimises the risk of developing infections and other problems.

We hope this guide helps you get to grips with your Mounjaro treatment. Want to learn more about Mounjaro? Discover SemaPen's expert-led Mounjaro medication programme or read our frequently asked questions.