Mounjaro

Mounjaro is a medication originally designed to control blood sugar levels for people with diabetes, which has since been licensed for weight loss too. It contains the active ingredient tirzepatide, which is a GIP receptor and GLP-1 agonist.^[1]

Currently, Mounjaro is the only licensed weight loss treatment available that contains both types of receptor agonist.

GIP and GLP-1 receptor agonists mimic the way natural GIP and GLP-1 hormones produced by your body work. GLP-1 receptor agonists help your body to produce more insulin when your blood sugar levels are high, and GIP receptor agonists help to increase your sensitivity to insulin.^[3]

The exact way they work to help you lose weight isn’t completely understood, but scientists believe they helps slow the movement of food from your stomach, making you feel full for longer. It’s thought the two types of receptor agonist affect your digestive system in complimentary ways, as they’re similar hormones that work in similar ways to produce similar results.

But we do know that together, GLP-1 receptor agonists and GIP receptor agonists are more effective than they are alone. A review of ten studies involving 9,873 patients found that tirzepatide support significantly more weight loss than placebo, GLP-1 receptor agonists alone, or insulin.^[4] This makes Mounjaro the most effective weight loss injection on the market right now.

In the UK, it’s only available as a weight loss treatment if you have a BMI over 30, or over 27 with a weight-related health problem, like pre-diabetes.

Mounjaro comes in pre-filled pens with six different doses. You’ll start on the lowest dose of 2.5mg, which gradually increases every four weeks.

How does Mounjaro work?

Tirzepatide, the active ingredient in Mounjaro, is a GLP-1 agonist receptor. It works similarly to semaglutide, the active ingredient in Ozempic and Wegovy.

It’s not completely understood how GLP-1 helps you lose weight, but studies have shown it can make you feel more full. GLP-1 is a hormone that naturally occurs in your body. When you eat something, it sends signals to your brain to tell it you’re satisfied or full. This helps control your appetite and stops you from eating too much. It also slows down the movement in your gut, preventing your food from entering the intestines so you feel full for longer. In short, GLP-1 works in your gut and brain to control your appetite.^[1]

It also affects the release of a hormone called GIP (gastric inhibitory polypeptide). This hormone is responsible for breaking down fatty foods, which can contribute to weight loss.^[2]

Although Mounjaro can help you lose weight, it’s recommended that you exercise regularly and eat a well-balanced, healthy diet to get the best results.

What doses of Mounjaro are there?

Mounjaro comes in pre-filled pens with six different doses: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg and 15 mg. You’ll start on the lowest dose of 2.5mg once a week and at the end of four weeks it will increase to the next dose, which is 5mg once a week. The dose will increase every four weeks (or longer if your clinician decides so) till the maximum dose of 15mg.

Each pen is pre-filled with a dose of either 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, or 15 mg. Each week inject the correct dose at the same time. It can be taken at any time during the day, but you’ll need to make sure you stick to that same time each week. So before using your first dose, it’s a good idea to wait until it’s a time and a day when you’re most likely to be free.

How to inject Mounjaro:

• Mounjaro can be injected in your stomach, upper leg and upper arm.
• The same area can be injected every week, just make sure it’s not the same spot.
• It can be injected with or without food.

If you want to stop taking Mounjaro, talk to your clinician first.

If you accidentally use more Mounjaro than you should’ve done, contact a clinician immediately for medical advice. Too much can lower your blood sugar levels, which can make you lightheaded or sick.

If you forget to take a dose of Mounjaro but it’s been less than four days, use it as soon as you remember. If it’s been more than four days, though, skip the missed dose and carry on with your normal dosing schedule.

How long does Mounjaro take to work?

In a 40-week-long study, people using Mounjaro showed significant weight loss results. On average, patients taking the:^[1]

• 5 mg dose lost of 17 lbs,
• 10 mg dose lost 21 lbs,
• 15 mg dose lost 25 lbs.

However, you might not get these results. Everyone will react differently to Mounjaro; some may get better results while others might lose less weight. It’s also important to exercise regularly and go on a calorie-controlled diet to get the best results.