Weight-loss medicines such as Mounjaro and Wegovy have opened new ways to treat obesity, but NHS access remains limited and services can differ depending on where patients live in England. In October 2026, Parliament's Health and Social Care Committee called for wider access to these drugs and a more consistent approach to treating obesity as a long-term condition.
How the medicines work
Mounjaro (tirzepatide) and Wegovy (semaglutide) act on hormone pathways involved in appetite. They can reduce hunger and help people feel full for longer. Both are given as weekly injections.
These medicines can produce substantial weight loss, although the amount varies between individuals. Side effects include nausea, vomiting, diarrhoea and constipation. People can also sometimes experience more severe side effects such as pancreatitis and visual problems. A clinical assessment is always needed to consider whether a drug is suitable for a patient.
Changes to diet and physical activity are also needed when people use these drugs, with support to help people maintain these changes. Because weight often returns after treatment stops, this reinforces the need to approach obesity as a long-term condition requiring continuing care from the NHS.
Eligibility for NHS treatment
There is a distinction between meeting the criteria recommended by the National Institute for Health and Care Excellence (NICE) and being able to access treatment via the NHS. For Mounjaro, NICE recommends treatment for adults with a body mass index (BMI) of at least 35 and at least one weight-related health condition.
Access to Mounjaro through primary care is being introduced in stages, prioritising people with greater clinical need. As of November 2026, the national criteria cover people with a BMI of at least 35 and at least four of five specified conditions: high blood pressure, abnormal levels of blood fats such as cholesterol, obstructive sleep apnoea, cardiovascular disease and type 2 diabetes.
Lower BMI thresholds are used for people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds because weight-related health risks can develop at a lower BMI. These BMI thresholds are usually reduced by 2.5 points for these groups.
Mounjaro is also available through specialist weight-management services under the broader NICE criteria. However, local referral arrangements, prioritisation and waiting lists affect access. Meeting the criteria does not guarantee an immediate appointment or prescription. Wegovy has different eligibility rules and is prescribed through specialist weight-management services for a maximum of two years under NICE's weight-management guidance.
Why access varies between areas
The national rollout explains some restrictions but local arrangements also matter. Integrated care boards – the NHS organisations responsible for planning and funding local services in England – organise access to weight-management treatment.
Areas differ in the capacity of their specialist services, the staff available and their arrangements for prescribing and monitoring medicines. Providing treatment requires more than funding the injections. Patients need assessment, support with eating and physical activity, and follow-up to review the benefits and side effects. These requirements help explain why services take time to develop but they do not remove the need to address unfair differences in access. The parliamentary committee highlighted a system in which many people obtain treatment privately while others cannot afford it.
An individual GP cannot change the rules. A practice may be working within a locally commissioned pathway and prescribing may be organised through another service.
How to find out what is available
Your GP practice can advise on the local pathway and whether you may be eligible for assessment. You can also check your integrated care board's website, searching for "weight management" or "tirzepatide". Check when the information was updated because eligibility and services do change.
Useful questions include whether you meet the current criteria, which service would assess you, whether a referral is needed and what waiting time to expect. Ask what support with eating, physical activity and behaviour change is included.
If you cannot currently access medication, ask what other support is available. Depending on your circumstances, this might include a weight-management programme, support from a dietitian or assessment for other treatments like weight-loss surgery. If you are considering private treatment, discuss the ongoing costs, monitoring and arrangements for continuing care. Use a registered pharmacy and tell your GP what medicines you are taking.
Weight-loss medicines are a useful addition to obesity treatment but access needs to be accompanied by appropriate support and follow-up. For now, checking your local pathway is the most practical way to understand your options. The challenge for the NHS is to make effective long-term care available more consistently across England.
