What is the recommended Mounjaro dosage for weight loss?

Mounjaro is an injectable drug that's clinically proven to help patients lose weight when combined with diet and exercise.

Mounjaro was approved for use in the UK in November 2023¹ and is available from private healthcare providers like SemaPen. The NHS also plans to offer it as a weight loss treatment, though decisions are still being made about how to roll it out.²

If you're interested in using the medication, you probably have questions about dosing. What's the best Mounjaro dose for weight loss? Should you start at a lower dose? And how often are you supposed to take the medication?

In this guide, we answer all these questions and more. Let's get started.

What Mounjaro doses are available?

Mounjaro comes as a KwikPen. This is a pen-shaped device that's designed to make it easy to inject medications at home.

There are six Mounjaro KwikPens available. Each is pre-loaded with a different dose of the drug:

2.5mg

5mg

7.5mg

10mg

12.5mg

15mg

Mounjaro should be taken once per week. Each pen contains four doses – enough for four weeks of treatment.

What's the best Mounjaro dose for weight loss?

Technically speaking, the most effective Mounjaro dosage for weight loss is the highest available dose (15mg).

In the main clinical trial looking at Mounjaro's safety and effectiveness, participants treated with the highest dose lost the most weight.³

Those on a 15mg dose lost 20.9% of their starting body weight, on average.

Those on a 10mg dose lost 19.5% on average.

Those on a 5mg dose lost 15% on average.

Those on a placebo lost 3.1% on average. A placebo is a harmless substance with no medical effects.

However, it's really important to start at a low dose and gradually build up to higher doses. This is so your body can get used to the medication.

What's the best Mounjaro starting dose for weight loss?

Taking Mounjaro is a bit like training for a marathon. You can't just turn up at the starting line and expect to make it to the finish on your first go.

No. Your body isn't used to it, so you need to start slowly and build up the intensity of your training as time goes on. The same goes for Mounjaro.

While the 15mg dose is technically the most effective, starting your treatment at this dose would be quite punishing on your body. You would likely experience severe side effects, which can include nausea, vomiting, stomach pain, diarrhoea and similarly unpleasant ailments.

That's why doctors recommend starting your Mounjaro treatment at the lowest dose: 2.5mg.

Only after you've taken four weekly doses can you step up to a 5mg dose. You should then increase your dose in 2.5mg increments every four weeks until you reach the 15mg dose.

Building up your dose like this has several benefits:

It gives your body time to get used to the medication.

It allows the levels of tirzepatide (Mounjaro's active ingredient) to stabilise in your body.

It helps make side effects less pronounced.

Mounjaro vs Ozempic dosing

You might have heard about people using the drug Ozempic for weight loss. How does the dosing schedule for Ozempic compare to Mounjaro?

Before we answer that question, we need to clear up a common misconception.

Ozempic is not meant as a weight loss medication. It's only approved in the UK to treat type 2 diabetes.