What BMI Do You Need to Have Mounjaro — and What Else the Prescriber Checks

Step 1, check whether your BMI meets the licensed threshold

The Mounjaro SmPC, which sets the terms of its UK licence, defines two routes in. The first is a BMI of 30 or above on its own. The second is a BMI of at least 27 if you also have one or more weight-related conditions: common examples include type 2 diabetes, pre-diabetes, high blood pressure, raised cholesterol, obstructive sleep apnoea, or osteoarthritis.

Those numbers are the entry point, not a guarantee of a prescription. They tell you whether a clinical assessment is worth starting, not whether tirzepatide is right for you specifically. The full picture of how BMI factors into Mounjaro eligibility covers the calculation in more detail, but the short version is: check your number, then talk to a prescriber about the rest.

One adjustment worth knowing: for adults of South Asian, Chinese, Middle Eastern, Black African or African-Caribbean backgrounds, UK guidance typically applies thresholds 2.5 kg/m² lower than the headline figures, so a BMI of 27.5 or above with a qualifying condition, rather than 30, may be the relevant line. If you want to understand what your BMI has to be to get Mounjaro, including how these ethnic-group adjustments apply in practice, NICE's appraisal of tirzepatide (TA1026) sets this out in the recommendations chapter for the NHS pathway, and private prescribers follow the same clinical logic.

Step 2, understand what else the prescriber is looking at

A prescriber reviewing your consultation is not simply ticking a BMI box. They are building a clinical picture from your responses: current medicines, medical history, relevant test results, and any conditions that would make Mounjaro unsuitable. Some conditions mean the medicine cannot be prescribed at all, a personal or family history of medullary thyroid carcinoma, for instance, or a history of pancreatitis.

Other medicines can interact with tirzepatide. Oral contraceptives deserve a mention here: for the first four weeks of treatment, and for four weeks after each dose increase, the NHS advises adding a non-oral method of contraception (condoms, for example) because tirzepatide slows gastric emptying and may reduce how much of the pill is absorbed. If you are on HRT, the NHS also suggests discussing transdermal forms (patches or gels) with your doctor. These are the kinds of details a thorough clinical assessment surfaces. You can read more about who can have Mounjaro, including the full contraindication list.

Anyone under 18, or who is pregnant, breastfeeding, or actively trying to conceive, falls outside the licensed indication entirely. There is no route around that.

Step 3, know the difference between the NHS and private thresholds

NICE recommended tirzepatide for NHS use in December 2024 (TA1026), but the NHS eligibility criteria are considerably stricter than the licensed thresholds above. The NHS is rolling out access in phases, the first cohort requires a BMI of 40 or above plus four or more specific weight-related conditions; a second cohort, covering BMI 35 to 39.9 with four or more conditions, opened in June 2026. Further phases are planned through 2027.

Private prescribing follows the licensed SmPC criteria rather than those phased NHS thresholds. That means adults who meet the BMI 30-or-above (or 27-plus-condition) standard can be assessed and, if clinically suitable, prescribed privately, without needing to qualify for the NHS route or wait for the next cohort. If you are asking what BMI you need to get Mounjaro under each route, the NHS and private BMI requirements compared goes into the phase details side by side.

If cost is a consideration, the Mounjaro price page explains what private treatment typically includes and how pricing is structured.

What the consultation at a registered pharmacy actually involves

At nume, once you complete the free online consultation, a GPhC-registered Independent Prescriber reads your answers the same day. Not software. A real clinician, deciding whether Mounjaro is appropriate for you based on everything you have shared. If approved, treatment is dispatched the same day for orders placed before 12pm on a working day, and DPD delivers it the next working day in plain, unbranded packaging. When the box arrives and you open it, you will find the KwikPen (a slim, pre-filled device with four weeks of doses in a single pen) along with the Patient Information Leaflet, which should be read before your first injection.

The prescriber also checks that your identity and current weight are verified. Transfer patients and those requesting a dose increase are asked to provide supporting evidence. None of this is box-ticking; it is what a clinical review looks like when it is done properly. You can find out more about how nume works or read the profile of our clinical team if you want to understand the people behind the prescribing decisions.

If you want to explore the broader range of weight-loss treatment options before deciding, our treatment overview sets out what is available and why one may suit you better than another. When you are ready to find out whether you are eligible, speak to our prescribers through a free consultation.