Eligibility
Weight-loss treatment eligibility is not decided by BMI alone. It can depend on your health history, current medicines, pregnancy or breastfeeding status, weight-related conditions, previous treatment experience and whether you are looking at NHS access or a private provider assessment.
Start with BMI, then check the health questions around it
BMI is often the first number used in weight-management guidance, but it is only a starting point. A clinician or pharmacist still needs to look at whether a medicine is suitable, what other health conditions are present and whether NHS or private access is being considered.
BMI and access checker
Check which questions may matter next
This tool estimates BMI and highlights common NHS and private-provider assessment questions. It does not decide eligibility, prescribe treatment or replace advice from a qualified healthcare professional.
It is more than a yes-or-no BMI check
BMI and health conditions
BMI can affect which treatment options are discussed, but weight-related conditions and personal health history often change the assessment.
Medicine safety
Current medicines, pregnancy or breastfeeding, side-effect history and certain health conditions can affect whether a medicine is suitable.
Access pathway
NHS access, specialist services, GP referral and private-provider assessment can all work differently.
Current NHS weight-loss medicine thresholds to understand
NHS access can vary by medicine, local service and rollout stage. The figures below are a guide to questions that may come up, not a guarantee of access.
| Medicine or setting | Common NHS eligibility starting point | Important extra context |
|---|---|---|
| Tirzepatide (Mounjaro) | Initial primary-care rollout: BMI 40+ or 37.5+ using adjusted thresholds, plus at least four of five listed weight-related conditions. | NHS England describes a phased rollout, with highest clinical need first and local services managing access. |
| Semaglutide (Wegovy) | BMI 35+ or 32.5+ using adjusted thresholds with weight-related health problems. BMI 30 to 34.9, or 27.5 to 32.4 adjusted, may depend on specialist-service criteria. | NHS England says Wegovy is prescribed through specialist weight-management services. |
| Orlistat | BMI 30+, or BMI 28+ with weight-related conditions. | NHS information says treatment should sit alongside diet, exercise or lifestyle changes and clinical or pharmacy advice. |
| Private provider assessment | Private services may ask similar BMI and health questions, but their process is separate from NHS access rules. | A displayed price does not confirm approval, suitability, stock or supply. |
What online providers may ask before treatment is considered
Height, weight and BMI
Expect questions about your current measurements and sometimes evidence such as photos or previous treatment records.
Medical history
Providers may ask about diabetes, blood pressure, sleep apnoea, cholesterol, heart disease, digestion, mental health and other conditions.
Medicines and safety
Current prescriptions, allergies, pregnancy or breastfeeding, contraception, previous side effects and surgery plans can all matter.
Follow-up needs
Some people need more support around dose changes, side effects, delivery, restarts or longer-term care.
What eligibility tools cannot do
It cannot approve treatment
A calculator can estimate BMI, but only a qualified clinician or pharmacist can assess suitability.
It cannot predict local NHS access
Integrated care boards and specialist services can apply local processes, capacity limits and phased rollout plans.
It should not replace advice
If you are unsure, have symptoms, take medicines or have a complex health history, speak to a qualified healthcare professional.
Where to go after checking eligibility questions
NHS vs private
Compare access, referral and assessment differences before choosing a provider page.
Weight-loss injections
Compare Mounjaro and Wegovy dose prices, checks, delivery and support.
Weight-loss tablets
Compare Orlistat, Xenical, Mysimba and other current oral options.
Providers
Browse provider pages once you know which treatment or access question matters most.
Current guidance used for this page
This page was reviewed against NHS England, NHS and local ICB guidance available on 15 May 2026. Eligibility details can change, so always check the linked official source and speak to an appropriate professional.
BMI bands are a guide, not a decision
BMI is one of the numbers used in many weight-management pathways, but it does not describe health history, medicines, side effects, pregnancy or breastfeeding, previous treatment or whether a specific provider can assess you safely.
Private providers usually need more than height and weight
Previous treatment
They may ask what you used before, the dose, side effects, gaps in treatment and whether you are switching or restarting.
Current medicines
Prescriptions, allergies and medicine interactions can affect whether a route is suitable or needs extra review.
Mental and physical health
Health history can affect assessment, support and whether a provider needs more information before continuing.
Pregnancy and feeding
Pregnancy, planning pregnancy or breastfeeding should be raised before any treatment decision is made.
Privacy note: the checker on this page runs in your browser. It is designed to show general questions to discuss with a clinician or pharmacist, not to store your answers or provide a diagnosis. See the privacy policy.