Am I Eligible for Mounjaro or Wegovy? UK Eligibility Explained

Wegovy and Mounjaro share the same licensed criteria for weight management, so the BMI thresholds are not where they differ. What determines whether either is appropriate for you goes considerably beyond a number.

Meeting the criteria makes you eligible to be assessed. It does not mean treatment will be supplied, and a prescriber declining is not an obstacle to be worked around. It usually means something in your history makes the medicine unsuitable.

This page sets out the licensed criteria, the conditions that count, who cannot take either medicine, the pregnancy and contraception position, and what an assessment actually examines.

Key things to know

• Both are licensed for adults with a BMI of 30 or above, or 27 to under 30 with at least one weight-related health condition.
• Both are licensed for use alongside a reduced-calorie diet and increased physical activity.
• Wegovy is licensed in the UK for adolescents aged 12 and over living with obesity. Mounjaro is licensed for adults only.
• NICE recommends using lower BMI thresholds when assessing people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds because cardiometabolic risk can occur at a lower BMI.
• A personal or family history of medullary thyroid cancer, or MEN2, is screened for and will normally rule treatment out.
• Neither is used in pregnancy, just before trying to conceive, or while breastfeeding.
• Meeting the BMI criteria is the starting point of an assessment, not the end of it.

The licensed eligibility criteria

Both medicines are licensed for weight management in adults on the same basis.

Both are also separately licensed for type 2 diabetes, which is a different indication with its own criteria.

Which weight-related conditions count?

For people with a BMI of 27 to under 30, at least one weight-related medical condition is required. Conditions that may be considered include: The conditions generally considered include:

• High blood pressure
• Type 2 diabetes, or raised blood glucose short of diabetes
• Abnormal cholesterol or other blood fats
• Obstructive sleep apnoea
• Cardiovascular disease
• Osteoarthritis affecting weight-bearing joints
• Fatty liver disease

A prescriber will want evidence rather than an impression. If you have been told you have one of these, say when, by whom, and whether you are being treated for it. If you suspect you have one but have never been assessed, that is worth establishing first, since it may change both your eligibility and the wider picture of your health.

Private prescribing must remain within the medicine's licensed indication, while NHS access is governed by NICE recommendations and local NHS pathways. These criteria can be more restrictive than the licensed indication and differ between medicines.

Lower BMI thresholds for some backgrounds

BMI does not carry the same risk for everyone. NICE advises using lower thresholds for people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family backgrounds, because cardiometabolic risk begins at a lower BMI in these groups.

In practice this means a prescriber may apply an adjusted threshold rather than the standard one. If this applies to you, mention your background at assessment rather than assuming the standard figures are the whole story.

Age: the clearest difference between them

This is the one eligibility difference that is straightforward.

Wegovy is licensed in the UK for adolescents aged 12 and over living with obesity, as well as for adults. Mounjaro is licensed for adults for weight management; it is not licensed for weight management for people under 18.

Both are prescription weight loss medications, and while Mounjaro is also used among diabetes medications, it may still be suitable for some adults without diabetes based on their health profile and eligibility criteria.

In practice, treatment in adolescents is uncommon and would involve closer clinical supervision than adult treatment. It is not something to pursue through a routine online consultation.

Who cannot take either medicine

Some situations rule treatment out. Others require careful assessment rather than an automatic no.

Reasons treatment is normally ruled out

• A previous serious allergic or hypersensitivity reaction to the medicine or one of its ingredients can rule treatment out. Your prescriber will also ask about your personal and family medical history, including thyroid and endocrine conditions, as part of the safety assessment.
• A previous serious hypersensitivity reaction to the medicine or one of its ingredients.
• Type 1 diabetes. These medicines are not substitutes for insulin and should not be used as a treatment for type 1 diabetes.
• Pregnancy, breastfeeding, or actively trying to conceive.
• Being under 18, for Mounjaro.
• Not meeting the licensed BMI criteria.
• Already taking another medicine in the same class. These are not combined.

Situations needing careful assessment

These do not automatically rule treatment out, but they change the conversation.

• A history of pancreatitis. The MHRA advises caution with this class of medicine.
• Gallbladder disease or gallstones.
• Severe gastrointestinal disease, including problems with stomach emptying and symptoms such as stomach discomfort.
• Current or previous eating disorders require careful assessment, and weight-loss treatment may not be appropriate until the eating disorder has been assessed and supported.
• Diabetic retinopathy, particularly where glucose control may change rapidly.
• Kidney or liver disease.
• Taking insulin or medicines that can cause low blood sugar, which may need reviewing before starting.
• Significant mental health conditions, depending on the circumstances.
• Being older or frail, where muscle loss and nutritional intake need more attention.

These conditions do not automatically mean treatment will be refused. They may simply mean that your prescriber needs more information, closer monitoring or a different treatment plan.

Pregnancy, contraception and planning a family

This is one of the most important eligibility areas and the one most often overlooked.

The MHRA position

The MHRA advises that GLP-1 medicines should not be used during pregnancy, just before trying to conceive, or while breastfeeding, because there is not enough safety data. It also advises that anyone of reproductive age taking one who could become pregnant should use effective contraception.

There is a specific point about Mounjaro. The MHRA has advised that tirzepatide may reduce the effectiveness of oral contraceptives in people who are overweight or living with obesity, and that those using oral contraception should switch to a non-oral method or add a barrier method for four weeks after starting and for four weeks after each dose increase.

Vomiting and diarrhoea, which are common with both medicines, can also reduce absorption of oral contraceptives.

If you are planning a pregnancy

Treatment needs to stop before trying to conceive, and the gap differs between the two medicines. The MHRA advises stopping semaglutide at least two months before trying to conceive, and tirzepatide at least one month.

Contraception should continue through that gap. Continue effective contraception during this washout period unless your healthcare professional advises otherwise.

If pregnancy is something you are considering within the next year, raise it at your assessment. It affects whether to start, which medicine might be appropriate, and how long you would expect to be on treatment.

A point about restored fertility

Weight loss may improve menstrual regularity and ovulation in some people whose cycles have been affected by excess weight. If pregnancy is not wanted, contraception should therefore be continued according to your healthcare professional's advice.

What the assessment actually covers

A proper clinical assessment, whether provided online or through the NHS, should consider:

1. Height, weight and BMI, against the licensed criteria and any adjusted threshold that applies to you
2. Weight-related health conditions, including when they were diagnosed and how they are managed
3. Your full medical history, including conditions you no longer consider relevant
4. Every medicine you take, including anything bought without a prescription, supplements and occasional medicines
5. Allergies, including reactions to any medicine in the same class
6. Family history, particularly of thyroid cancer and endocrine conditions
7. Pregnancy, breastfeeding and contraception
8. Previous weight management treatment, what happened and why it stopped
9. Your relationship with food, including any history of disordered eating
10. May also include alcohol and smoking

NHS access may require referral to specialist services for managing weight and is assessed under stricter NICE-based eligibility criteria than private prescribing.

The assessment is not a form to get past. It is the mechanism that establishes whether a medicine that acts on digestion, blood glucose and appetite signalling throughout the body is safe for you specifically, and whether your prescriber or other healthcare provider can prescribe it appropriately.

Why a prescriber may decline

A prescriber must be able to say no. A service where that never happens is not conducting an assessment.

Common reasons for declining:

• You do not meet the licensed criteria
• A condition in your history makes the medicine unsuitable
• Another medicine you take creates a problem
• Information is missing or inconsistent, and clarification is needed
• There is a safety concern that needs investigating first
• Current or recent disordered eating, where other support should come first
• The timing is wrong, for example a planned pregnancy

Declining is not a judgement about you, and it is not a sales decision. It is the system working as intended.

If you are declined, ask what would change the answer. Sometimes the obstacle is temporary, such as a medicine review or a test result, and sometimes it points to something worth addressing in its own right.

Meeting the criteria is not the same as being suitable for weight loss treatments

This distinction causes a lot of frustration and is worth stating plainly.

The BMI criteria establish who the medicine has been licensed for. They do not establish that it is the right treatment for a particular person at a particular time.

Two people with identical BMIs can receive different answers because of their history, their other medicines, their other conditions or their circumstances. That is appropriate rather than inconsistent.

It also works the other way. Someone who meets the criteria comfortably may still be better served by addressing something else first, whether that is an untreated condition, a medicine contributing to weight gain, or support for eating difficulties.

If you are not eligible

Not being eligible for one of these medicines is not the end of the conversation.

• If your BMI is below the threshold, the licensed criteria exist because the balance of benefit and risk was assessed for a defined population. Other approaches to weight management remain available.
• If a condition rules it out, treating that condition may be the more valuable intervention anyway.
• If a medicine you take is the obstacle, a review may find an alternative, and that is a conversation worth having regardless.
• If timing is the issue, such as a planned pregnancy, the criteria will still be there afterwards.
• If eating difficulties are part of the picture, support for those comes first, and that is a clinical priority rather than a delay.

What is not a reasonable response is obtaining the medicine without an assessment. A supply that does not involve one is not a cheaper or faster route to the same thing. The MHRA has found illegally supplied weight loss pens containing insulin rather than the labelled medicine, which caused dangerously low blood sugar and hospital admissions.

Red flags

Seek urgent medical attention for severe and persistent stomach pain that may spread through to your back, with or without nausea and vomiting; swelling of the face, lips, tongue or throat; difficulty breathing; or signs of significant dehydration.

Contact your prescriber if your health changes during treatment, if you become pregnant or are planning to, if you start a new medicine, or if side effects are not settling.

Preparing for your assessment

The single most useful thing you can do is arrive with specifics. When you were diagnosed with each condition, what you take and at what dose, what you have tried before and what happened, and any family history of thyroid or endocrine conditions.

Assessments go wrong far more often through vague answers than through complicated histories. A prescriber can work with a complicated history. What they cannot work with is a picture that turns out to be incomplete after treatment has started.

Medical Disclaimer

This article is for general information only. It is not medical advice and it does not replace the patient information leaflet supplied with your medicine or an individual assessment by an appropriately qualified healthcare professional.

mounjaro and wegovy are prescription-only medicines. Both are weekly weight loss injection treatments and should only be used under the supervision of an appropriately qualified prescriber, following a clinical assessment that considers your medical history, current medicines and other conditions. Treatment suitability depends on an individual clinical assessment, and results vary between individuals. Meeting the licensed criteria does not mean treatment will be supplied.

The MHRA advises that these medicines should not be used during pregnancy, just before trying to conceive, or while breastfeeding, and that anyone who could become pregnant should use effective contraception.

Do not obtain prescription medicines outside the regulated system. Seek urgent medical attention for severe and persistent stomach pain that may spread to your back, swelling of the face, lips, tongue or throat, difficulty breathing, or signs of significant dehydration.