Prescribing weight loss medications in south west London – tirzepatide (Mounjaro®)

Tirzepatide works by supressing appetite centres in the brain that control gut hormones. It decreases the appetite and slows the movement of food passing through the body, making you feel fuller for longer.  

Clinical trials have shown tirzepatide can help people living with obesity lose up 20% of their starting body weight, depending on the dose and accompanying diet and lifestyle support. 

Tirzepatide can only be prescribed by a healthcare professional alongside programmes which support people to lose weight and live healthier lives by making changes to their diet and physical activity 

Tirzepatide comes as an injection, which can be self-administered once a week.  

 At this stage – phase one – the medication is available only to patients who meet specific criteria:

• A Body Mass Index (BMI) over 40 (Note: The BMI threshold is reduced by 2.5 kg/m2 for people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean ethnic backgrounds) and

• At least four of the specified weight-related health conditions, such as type 2 diabetes, high blood pressure, high cholesterol, sleep apnoea, or cardiovascular disease.

We anticipate that the eligible patient group for phase two, will have access to the medication from July 2026. The criteria will be:

• A Body Mass Index (BMI) between 35 – 39.9(Note: The BMI threshold is reduced by 2.5 kg/m2 for people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean ethnic backgrounds) and

• At least four of the specific weight-related health conditions, such as type 2 diabetes, high blood pressure, high cholesterol, sleep apnoea, or cardiovascular disease.

A time frame and criteria for phase three will be published near to November 2026.

Body Mass Index is a measurement of your weight in kg divided by your height in meter squared. If you do not know your BMI, you can work it out using a free online NHS calculator.

Introducing this new treatment to NICE’s estimated 3.4 million eligible patients requires the NHS in England to develop a completely new service for primary care and many healthcare professionals will need to be trained to deliver it. 

A staged approach will help manage demand on existing healthcare services. This allows the safe prescribing of tirzepatide and the appropriate support for patients. 

Tirzepatide will initially be offered to individuals facing the most significant health risks related to their weight.

Tirzepatide will not immediately be available and will not be accessible to everyone who wishes to use it. Initially, tirzepatide will only be available on the NHS to those expected to benefit the most. People who are eligible for tirzepatide phase one through primary care services should only expect to start to get access by mid 2025. 

Patients can continue taking tirzepatide if they are prescribed it to manage their diabetes.  

If patients are using tirzepatide they have acquired privately, they may be able to access the medication through an NHS prescription if they meet the NICE and NHS qualifying criteria.

A healthcare professional will determine if it is appropriate for you to receive tirzepatide as part of your care in a different care setting (for example, through primary care). 

Any patient prescribed tirzepatide must participate in the specifically designed ‘wraparound’ care required by NICE guidance. This focuses on diet, nutrition and increasing physical activity.

As NHS England develops the service, it will provide more details of the wraparound support offer for patients who qualify. Patients cannot be prescribed tirzepatide if they do not wish to undertake the wraparound care support. 

Normal prescription charges will apply unless you are entitled to free NHS prescriptions (for example, because you have a medical exemption certificate).

People in England over the age of 18 who are living with obesity and another weight-related health issue will be able to access the weight loss drug tirzepatide through specialist weight management services (SWMS) from spring 2025. In primary care services, access will begin in summer 2025.

Tirzepatide is currently prescribed for the treatment of type 2 diabetes but will now also be available for weight loss purposes.

Introducing this new treatment to NICE’s estimated 3.4 million eligible patients requires the NHS in England to develop a completely new service for primary care and many healthcare professionals will need to be trained to deliver it. 

A staged approach will help manage demand on existing healthcare services. This allows the safe prescribing of tirzepatide and the appropriate support for patients. 

Tirzepatide will initially be offered to individuals facing the most significant health risks related to their weight, starting in spring 2025 through specialist weight management services (SWMS). 

Tirzepatide will not immediately be available and will not be accessible to everyone who wishes to use it. Initially, tirzepatide will only be available on the NHS to those expected to benefit the most. People who are eligible for tirzepatide through primary care services should only expect to start to get access by mid 2025. 

A staged approach to service rollout within primary care means NHS in England will manage the flow of patients to the health system so it does not become overwhelmed.   

This approach will ensure the service is delivered safely and that the NHS in England is able to plan for an increase in service demand, whilst building specific skills and knowledge within the workforce.