Medication for weight loss: Tirzepatide (Mounjaro®)

Tirzepatide, commonly known as Mounjaro®, is a new medication recently recommended by the National Institute for Health and Care Excellence (NICE) for some adults living with obesity. In June 2025, GP practices began offering it to eligible patients on the NHS in a staged rollout.

Access to tirzepatide (Mounjaro®) through your GP practice

For the first year, it was offered to people with a BMI of 40 or more (or 37.5 in certain ethnic groups) who are also managing four or more health conditions – These are hypertension, Type 2 diabetes, sleep apnoea, hyperlipidaemia (high cholesterol) and cardiovascular disease. These need to be diagnosed by a healthcare professional.

From June 2026, the eligibility criteria have widened and now tirzepatide (Mounjaro) can be offered to adults with a BMI of 35 or more (or 32.5 in certain ethnic groups) who are living with four or more of the health conditions described above.

This prioritisation has been nationally set and has been focused to support people facing the greatest risk of, or who are experiencing, severe ill health due to obesity.

Tirzepatide (Mounjaro®) must be prescribed as part of a support programme, also known as wraparound care. This includes advice on healthy eating, physical activity, and lifestyle changes. You must agree to take part in this support to receive the medication.

Requesting tirzepatide (Mounjaro®) for weight loss

We know that many people are asking about tirzepatide (Mounjaro®) after hearing about how effective it can be in helping with weight loss.

As your Integrated Care Board (ICB), and following national guidance, we must make sure treatments are used fairly and within the budget we have available for our population.

We appreciate that this might feel frustrating, especially when private options are being advertised.

GP surgeries will contact priority patients to invite them to make an appointment to find out more.

For more information about tirzepatide (Mounjaro®) in Bristol, North Somerset and South Gloucestershire, please see the frequently asked questions below.

Frequently asked questions

 

Why is access being rolled out in stages?

The NHS needs time to safely introduce this new service, train healthcare staff, and manage demand.

A staged rollout allows those with the greatest clinical need to be prioritised first and ensures safe and sustainable delivery.

 

What is being done to prepare?

We’re developing a new approach to provide access to tirzepatide (Mounjaro®) through GP practices.

  • We’re making sure GPs and other services are trained and ready to support and safely prescribe this new medication.
  • We’re mapping out all weight management services available in Bristol, North Somerset and South Gloucestershire to help people find the right support for their needs.

 

What if I am already using tirzepatide (Mounjaro®)?

Patients can continue taking tirzepatide (Mounjaro®) if they are prescribed it by the NHS to manage their diabetes.
If patients are using tirzepatide (Mounjaro®) bought privately, they may be able to access the medication through an NHS prescription if they meet the NHS qualifying criteria.
It is important your GP is aware you are taking tirzepatide (Mounjaro®), if it hasn’t been prescribed by the NHS, as it may impact your health and other treatments.

 

Will I need to pay for tirzepatide (Mounjaro®)?

Standard NHS prescription charges will apply, unless you qualify for free prescriptions (e.g. with a medical exemption certificate).

Who will be eligible for tirzepatide (Mounjaro®)?

Tirzepatide (Mounjaro®) will initially be introduced in stages over three years:

Year 1 (started June 2025):

  • Adults with a Body Mass Index (BMI) of 40 or more, and
  • Four or more weight-related health conditions (see list below)

Year 2 (started June 2026):

  • Adults with a BMI between 35 and 39.9, and
  • Four or more weight-related health conditions

Year 3:

  • Adults with a BMI of 40 or more, and
  • Three or more weight-related health conditions

Adjusted BMI threshold  for certain ethnic backgrounds

For people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds, BMI thresholds are 2.5 units lower, due to a higher risk of health problems at lower body weights.

 

What counts as a weight-related health condition?

To be eligible in years 1 and 2 (June 2025 to June 2027), you must have four or more of the following health conditions. All conditions must be confirmed by a healthcare professional:

  • Type 2 diabetes
  • High blood pressure (hypertension)
  • Heart disease caused by narrowed or blocked arteries (atherosclerotic cardiovascular disease)
  • Obstructive sleep apnoea
  • Abnormal blood fats (dyslipidaemia)

 

How does tirzepatide (Mounjaro®) work?

Tirzepatide (Mounjaro®) is a GLP-1/GIP agonist. Like semaglutide (Wegovy®) and liraglutide (Saxenda®), it mimics gut hormones released after eating, helping you feel full, slowing stomach emptying, and improving blood sugar control.
Until now, most of these medicines have been used in the NHS to treat diabetes.
Tirzepatide (Mounjaro®) must be prescribed alongside a support programme to help with behavioural change, diet and physical activity. It is a weekly self-injection.
More information can be found on Gov.uk.

 

What are side effects of the medication?

Like all medications, tirzepatide (Mounjaro®) can cause side effects. These will be discussed with you by a healthcare professional and are also listed in the Patient Information Leaflet. Common side effects include:

  • Feeling sick
  • Indigestion (heartburn)
  • Constipation

More serious side effects may include:

  • Low blood sugar
  • Gallstones
  • Pancreatitis (inflammation of the pancreas)

 

Report any side effects using the Yellow Card Scheme (the UK’s medicine safety system).

How long can or should I take it for?

NICE guidance recommends stopping the medication if you do not lose at least 5% of your body weight after six months on the highest dose you can manage.
There is no fixed maximum treatment duration — ongoing use will be reviewed with your healthcare professional.

 

Can I take it if I’m pregnant or trying to get pregnant?

Tirzepatide (Mounjaro®) should not be used during pregnancy or just before trying to conceive, due to a lack of safety data.
There is specific information about how these medications affect contraceptive methods. See the “Patient Information GLP-1 agonists and contraception” leaflet by the Faculty for Sexual and Reproductive Health.

 

Is it okay to take tirzepatide (Mounjaro®) with the other medications that I take?

Tirzepatide (Mounjaro®) can affect the absorption of other medications, which might change how well they work.
Before starting, a healthcare professional will check what medicines you’re taking.
You may need dose adjustments if your long-term conditions (like high blood pressure) improve.
Be honest about all medicines you take, including over-the-counter products.

 

What support is available now?

Even though tirzepatide (Mounjaro®) may not be available to you, you can still access these services: