Mounjaro (tirzepatide) is a prescription-only medication in the UK, meaning a qualified prescriber must assess your suitability before you can start treatment. Understanding the eligibility criteria can help you prepare for that conversation.
Eligibility for Weight Management
To be prescribed Mounjaro for weight loss in the UK, you typically need to meet the following criteria:
- A BMI of 30 or above (classified as obese), or
- A BMI of 27 or above with at least one weight-related health condition such as type 2 diabetes, high blood pressure, high cholesterol, or obstructive sleep apnoea
- You must be 18 years or older
- Previous attempts at weight management through diet and exercise should have been made
Eligibility for Type 2 Diabetes
Mounjaro is also licensed for improving glycaemic control in adults with type 2 diabetes. Your GP or diabetologist may consider it if existing treatments such as metformin are insufficient or not tolerated.
Who Should Not Take Mounjaro?
Mounjaro is not suitable for everyone. You should not use it if you:
- Have a known allergy to tirzepatide or any of the pen's ingredients
- Have type 1 diabetes
- Have a personal or family history of medullary thyroid carcinoma (MTC)
- Have Multiple Endocrine Neoplasia syndrome type 2 (MEN 2)
- Are pregnant, planning to become pregnant, or breastfeeding
- Have a history of severe pancreatitis
Conditions That Require Caution
Certain health conditions don't necessarily rule out Mounjaro, but your prescriber will need to consider them carefully:
- Gastroparesis or severe gastrointestinal disease
- Kidney disease — dehydration from GI side effects can worsen renal function
- Diabetic retinopathy — rapid blood sugar improvements may temporarily worsen eye complications
- Mental health conditions — some patients report mood changes on GLP-1 medications
Interactions With Other Medications
Mounjaro slows gastric emptying, which can affect the absorption of oral medications. If you take other medicines — particularly those with a narrow therapeutic window such as warfarin or the oral contraceptive pill — let your prescriber know. Dose timing adjustments may be needed.
Next Steps
If you believe you meet the eligibility criteria, your first step is to speak with a prescriber — either your NHS GP, a private weight management clinic, or a registered online pharmacy that offers clinical consultations. You can compare the cost of Mounjaro prescriptions from UK pharmacies on MedsLens to find an affordable route to treatment.