Who Can Get Weight Loss Injections in the UK?

In the UK, weight loss injections such as Mounjaro (tirzepatide) and Wegovy (semaglutide) are licensed for adults with a BMI of 30 or more, or a BMI of 27 to 30 with at least one weight-related health condition, used alongside a reduced-calorie diet and more physical activity. Lower BMI thresholds are used for people from some ethnic backgrounds. NHS eligibility is narrower, usually requiring a BMI of at least 35 plus a weight-related condition, with stricter criteria in the early stages of the Mounjaro roll-out. Meeting the criteria does not guarantee a prescription: a prescriber must also check that treatment is safe for you. This guide explains who can, and who may not, get weight loss injections.

The three layers of eligibility

It can help to think about eligibility in three layers:

1. The licence: the conditions under which the MHRA has authorised the medicine, set out in the Summary of Product Characteristics (SmPC). This is the outer boundary for prescribing.
2. NHS criteria: the narrower groups for whom NICE has judged the medicine cost-effective for the NHS, plus any phasing set by NHS England or local health boards.
3. Individual suitability: whether the medicine is safe and appropriate for you specifically, given your health, history and other medicines.

Private prescribers work within layer 1 and must always consider layer 3. NHS prescribers work within layer 2 and also consider layer 3.

Licensed criteria

Mounjaro (tirzepatide)

Mounjaro is licensed for weight management in adults, as an addition to a reduced-calorie diet and increased physical activity, with:

• a BMI of 30 kg/m² or more (obesity), or
• a BMI of 27 kg/m² to less than 30 kg/m² (overweight) with at least one weight-related condition, such as prediabetes or type 2 diabetes, high blood pressure, abnormal blood fats, obstructive sleep apnoea or cardiovascular disease.

Wegovy (semaglutide)

Wegovy has similar adult criteria. It is also licensed:

• for some adolescents aged 12 and over with obesity, usually under specialist care
• to reduce the risk of major cardiovascular events in some adults with established cardiovascular disease and a BMI of 27 or more, based on the SELECT trial

In January 2026, the MHRA approved a higher maximum dose of 7.2mg weekly for adults with obesity (BMI 30 or more) only. It does not apply to people with a BMI under 30 or to those using Wegovy only for cardiovascular risk reduction. Check the current SmPC for details.

Saxenda (liraglutide)

Saxenda is licensed for adults with similar BMI criteria and for some adolescents aged 12 and over. It is a daily injection and is used less often now than the weekly options.

Summary of licensed criteria

For a fuller comparison of the medicines, see every UK weight loss injection compared and our overview of weight loss injections.

How BMI is used

Body mass index (BMI) is your weight in kilograms divided by your height in metres squared. It is a simple screening tool and does not measure body fat directly, distinguish muscle from fat, or show where fat is stored. Despite these limitations, it is the main measure used in licences and NICE guidance.

NICE guideline NG246 recommends these lower thresholds for people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family background, because they tend to develop weight-related conditions such as type 2 diabetes at a lower BMI. Our guides to BMI and treatment eligibility and BMI thresholds and ethnicity explain this in detail. You can check your BMI with our BMI calculator.

NICE also recommends measuring waist-to-height ratio alongside BMI in people with a BMI under 35, as a measure of central (abdominal) fat. A ratio of 0.5 or more indicates increased health risk.

Weight-related conditions

The licences and NICE guidance refer to weight-related conditions (sometimes called comorbidities). Common examples include:

• prediabetes (non-diabetic hyperglycaemia) or type 2 diabetes
• high blood pressure (hypertension)
• abnormal blood fats (dyslipidaemia), such as high cholesterol
• obstructive sleep apnoea
• cardiovascular disease, such as previous heart attack or stroke

Other conditions that may be relevant include osteoarthritis, fatty liver disease and polycystic ovary syndrome, although which conditions count can depend on the specific licence, guidance or provider policy. A prescriber may ask for evidence of a diagnosis, such as a GP record.

NHS eligibility

Wegovy on the NHS

NICE TA875 recommends semaglutide within specialist weight management services for adults with at least one weight-related condition and a BMI of at least 35, or 30 to 34.9 if they meet criteria for referral to specialist services, with lower thresholds for some ethnic groups. Treatment is for a maximum of two years, and NICE advises considering stopping if less than 5% of initial weight has been lost after six months. See Wegovy on the NHS.

Mounjaro on the NHS

NICE TA1026 recommends tirzepatide for adults with a BMI of at least 35 and at least one weight-related condition, with a lower threshold (usually by 2.5) for some ethnic groups. Because so many people are eligible, NHS England is phasing access. Its interim commissioning guidance set out:

Later cohorts are expected to widen access further over time. Local implementation varies, and Scotland's arrangements are decided separately. See Mounjaro on the NHS and private vs NHS weight loss treatment.

Who may not be suitable

Even if you meet the BMI criteria, a prescriber may decide a weight loss injection is not right for you. The SmPCs and clinical guidance set out situations where these medicines should not be used or need extra care. Our guide to who should not take GLP-1s covers this in depth.

Pregnancy, trying to conceive and breastfeeding

GLP-1 medicines should not be used during pregnancy or breastfeeding. Weight loss is not recommended in pregnancy, and animal studies have shown potential harm. If you are planning a pregnancy, the medicine needs to be stopped in advance; for example, the Wegovy SmPC advises stopping at least two months before a planned pregnancy because semaglutide stays in the body for several weeks.

The MHRA has also advised that tirzepatide may reduce the effectiveness of oral contraceptives in people who are overweight or obese, and recommends a non-oral method or adding a barrier method for four weeks after starting and after each dose increase. See GLP-1s, pregnancy and fertility and GLP-1s and contraception.

Medical history needing caution

A prescriber will want to know if you have, or have had:

• pancreatitis (inflammation of the pancreas)
• gallbladder disease or gallstones
• severe gastrointestinal disease, such as gastroparesis (delayed stomach emptying) or inflammatory bowel disease
• type 1 diabetes, as these medicines are not a substitute for insulin
• diabetic retinopathy (diabetic eye disease), which can temporarily worsen when blood sugar improves rapidly
• kidney or liver problems, particularly severe impairment
• medullary thyroid cancer or multiple endocrine neoplasia type 2 (MEN2), personal or family history; while this is a formal contraindication in US labelling, UK prescribers usually ask about it and may advise against treatment
• an eating disorder, current or past, such as anorexia, bulimia or binge eating disorder

Other medicines

Some medicines need extra care alongside GLP-1s:

• insulin and sulfonylureas (for diabetes), because of the risk of low blood sugar
• oral contraceptives, particularly with tirzepatide
• medicines with a narrow therapeutic range, such as warfarin, where slowed stomach emptying might affect absorption and monitoring may be needed
• other GLP-1 medicines, which should not be combined

See GLP-1 medication interactions.

Age

Mounjaro is licensed for adults only. Wegovy and Saxenda have adolescent licences but adolescent treatment is usually managed by specialists. Most private providers only treat adults, and some set an upper age limit or require additional checks for older adults, who may be more vulnerable to dehydration and muscle loss. See GLP-1s over 65.

How private providers assess eligibility

Regulated online pharmacies and clinics follow a structured process:

1. Medical questionnaire covering your weight history, health conditions, medicines, allergies, pregnancy status and mental health, including screening for eating disorders.
2. Identity and age checks, often using document checks or electronic verification.
3. Weight and height verification, which may involve a video consultation, a photo or video of you on scales, or confirmation from your GP or another healthcare professional.
4. Prescriber review, where a registered doctor, pharmacist prescriber or nurse prescriber decides whether to prescribe. They may ask for more information or decline.
5. GP communication, with your consent, so your GP knows about the medicine.

General Pharmaceutical Council (GPhC) guidance, strengthened in 2025, expects online pharmacies prescribing weight loss medicines to verify key information independently, rather than relying only on what a patient enters in a questionnaire. See our guides to online weight loss consultations and ID and weight verification.

Why a provider might decline

A provider might decline to prescribe if:

• your verified BMI does not meet the licensed criteria
• you are pregnant, breastfeeding or planning a pregnancy soon
• you have a condition or history that makes treatment unsafe
• there are signs of a current or past eating disorder
• you take medicines that make treatment risky without closer monitoring
• they cannot verify your identity, weight or medical history

Being declined can be frustrating, but it is an important safety check. You can ask for the reason and discuss alternatives with your GP.

Common situations and how the criteria apply

The examples below show how the criteria generally apply. They are illustrations of the rules, not predictions of what a prescriber will decide in any individual case.

BMI of 30 or more with no other conditions

You are within the licensed criteria for Mounjaro and Wegovy, so a private prescriber may consider treatment after a full assessment. You are unlikely to meet NHS criteria for weight loss medicines, which require a higher BMI and at least one weight-related condition. Your GP may still be able to refer you to NHS lifestyle support.

BMI between 27 and 30 with a weight-related condition

You may be within the licensed criteria if you have a qualifying condition such as high blood pressure, prediabetes or obstructive sleep apnoea. A private prescriber may ask for evidence of the diagnosis. NHS medication criteria are unlikely to apply unless lower ethnicity-adjusted thresholds bring you into scope for specialist services.

BMI between 27 and 30 with no weight-related condition

You are generally outside the licensed criteria for weight loss injections, unless a lower threshold applies because of your ethnic background. Lifestyle support, and a conversation with your GP about your health risks, is the usual starting point.

A lower BMI from a South Asian, Chinese, Black African or Caribbean background

Lower BMI thresholds, usually by 2.5 kg/m², are used in NICE guidance and in the NHS Mounjaro roll-out. Private providers vary in how they apply these within the licence, so ask how they assess eligibility. See BMI thresholds and ethnicity.

Already taking a weight loss injection and your BMI has fallen

If you have been on treatment and your BMI is now below the starting threshold, prescribers generally base continuing eligibility on your starting BMI and your response to treatment, rather than requiring you to stay above the threshold. Keep records of your starting weight and any verification, especially if you switch providers. See switching providers mid-treatment.

Type 2 diabetes

Type 2 diabetes counts as a weight-related condition and is one of the five qualifying conditions in the NHS Mounjaro roll-out. If you take insulin or a sulfonylurea, your diabetes treatment may need adjusting to reduce the risk of low blood sugar. Your diabetes team or GP should be involved. See GLP-1s and type 2 diabetes.

Previous bariatric surgery

Having had weight loss surgery does not automatically rule out GLP-1 treatment, but it requires careful assessment of your nutrition, absorption and surgical history, ideally with input from your surgical or specialist team. See GLP-1 medication vs bariatric surgery.

Eligibility for the newer tablets

At the time of writing, the MHRA has authorised two oral GLP-1 medicines for weight management: the Wegovy tablet (oral semaglutide), approved in 2026, and Foundayo (orforglipron), approved in August 2026. Their licensed criteria, as reported at approval, are similar to the injections: adults with a BMI of 30 or more, or 27 to 30 with at least one weight-related condition. Neither had completed NICE appraisal for NHS use at the time of writing. Check the MHRA and current SmPC for up-to-date information. See our oral GLP-1 guide.

Checking your own eligibility

Our eligibility checker gives a general indication based on BMI, conditions and age. It is informational only and is not a prescribing decision. If you think you might be eligible:

• For NHS treatment: speak to your GP. They can check your BMI, record any weight-related conditions and refer you to local services.
• For private treatment: choose a regulated provider and complete an honest consultation. Our providers page compares regulated UK services, and our prices page explains what affects cost.

Practical points before starting

If you are found eligible, it is worth thinking about:

• Contraception and pregnancy plans, as above.
• Upcoming surgery or procedures, as GLP-1s slow stomach emptying and anaesthetists need to know. See GLP-1 surgery and anaesthesia.
• Diet and activity, which are part of the licensed use. See what to eat on a GLP-1.
• Long-term plans, because weight is often regained after stopping. See long-term GLP-1 use.
• Cost over time, if paying privately. See how weight loss injection pricing works.

When to speak to a professional

Speak to your GP, a pharmacist or a prescriber if you are thinking about weight loss injections. Be open about your full medical history, medicines and any history of disordered eating. Never use a weight loss injection prescribed for someone else or obtained without a prescription.

Seek urgent medical help (NHS 111, or 999 in an emergency) if, while taking a weight loss injection, you experience:

• severe, persistent abdominal pain, possibly spreading to your back, with or without vomiting (possible pancreatitis)
• pain in the upper right abdomen, fever, or yellowing of the skin or eyes (possible gallbladder problems)
• persistent vomiting or diarrhoea with signs of dehydration
• swelling of the face, lips or throat, or difficulty breathing
• symptoms of low blood sugar if you take diabetes medicines, such as shaking, sweating or confusion
• changes in your vision if you have diabetic eye disease
• new or worsening low mood or thoughts of self-harm

If you are worried about your relationship with food or your body, speak to your GP. Support is also available from the eating disorder charity Beat.