Everything you need to know about Mounjaro

GLP-1(weight loss) injections 2:22 min watch Published 22 July 2025 Dr Ravi Assomull, Consultant Cardiologist

Dr Ravi Assomull explains how Mounjaro (Tirzepatide) works to support weight loss, how to take it safely, and what side effects to expect. He also shares key tips on diet and exercise to maximise fat loss while protecting muscle.

Have a question about your own heart health? Book a consultation with Dr Assomull – no GP referral needed, appointments typically within one working day.

Transcript

You've been prescribed Mounjaro, also known as Terzepidide, to support your weight loss journey. This medication is a type of weekly injection that works by mimicking natural hormones in your body to help control appetite, blood sugar and metabolism. We usually start with a low dose of 2.5mg once a week for 4 weeks, giving your body some time to adjust.

After that we'll increase the dose often to 5mg or higher depending on your goals and how you respond. It's important to take it on the same day each week and you can inject it into your thigh, upper arm or stomach. Just make sure to rotate the site each time.

Like all medications, Mounjaro can have side effects. The most common ones are nausea, diarrhoea or constipation, especially when starting. These often settle as your body gets used to it.

Rarely more serious issues like pancreatitis or allergic reactions can occur so you should seek medical attention straight away if you have severe abdominal pain or any unusual symptoms. There are some specific conditions where this medication isn't suitable. For example, if you or a family member has a history of certain rare thyroid cancers.

If you are diabetic, it is essential that you have regular monitoring of your eyes, as some reports suggest it can make eye disease related to diabetes worse. A few key reminders, never share your injection pen, inspect it before usage to ensure it is clear and if you miss a dose, you have up to 5 days to catch up, otherwise just wait for the next scheduled dose. It is also critical to support your weight loss journey with a carefully crafted nutrition plan which crucially includes adequate protein intake and is free of ultra processed food.

Additionally, a resistance-based exercise program with regular weight lifting will minimise the risk of losing muscle mass. The key here is to ensure all weight loss is fat loss, not muscle loss. If you have any questions don't hesitate to reach out.

We're here to support you every step of the way.

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