Weight loss injections: How do drugs like Wegovy and Mounjaro work?

At the moment, only Wegovy is available on the NHS in England, Wales and Scotland.

It must be prescribed by a weight management specialist, and access to these is restricted.

To qualify, adults must be obese and have at least one pre-existing weight-related health condition such as high blood pressure.

People with cardiovascular disease who are classed as overweight, but not quite obese, can also be given the drug.

Patients should follow a diet and physical activity programme, and the drug should be only prescribed for a maximum of two years, according to NHS guidelines.

The National Institute for Health and Care Excellence (NICE) has recommended that Mounjaro should also be offered to NHS patients in England from March 2025, alongside advice on diet and exercise.

As with Wegovy, it will initially only be available to obese patients who have a weight-related health condition and are under the care of a specialist.

However, from June, the drug will be offered more widely. It is not clear how this will be managed, or who will provide ongoing monitoring and support.

Detailed NHS England guidance is expected in early 2025.

It is possible that around 3.4 million people could eventually qualify for Mounjaro.

To help manage demand, Nice has said the NHS can take more than a decade to roll out access to the drug. It is thought 300,000 could benefit in the first three years.