What BMI Do You Need for Mounjaro in the UK?

The BMI threshold for Mounjaro#

Mounjaro (tirzepatide) is licensed in the UK for weight management if your BMI is 30 or above. It's also licensed from a BMI of 27 if you have at least one weight-related health condition, such as high blood pressure, high cholesterol, or obstructive sleep apnoea.

These figures come from the UK product information (the SmPC) approved by the MHRA. They set the outer limit of who the medicine is licensed for. Meeting the licensed BMI doesn't automatically mean the NHS will fund your treatment. NHS criteria, set by NICE, can be narrower than the licence.

Why these particular numbers#

Tirzepatide works differently to older weight-loss injections. It acts on two gut hormones at once, GLP-1 and GIP, both of which affect appetite and blood sugar. Working on both together tends to produce stronger average weight loss than GLP-1 alone in clinical trials.

The BMI thresholds themselves aren't unique to Mounjaro, though. They follow the same pattern used across UK obesity guidance generally: a BMI of 30 reflects obesity on its own, and 27 reflects overweight combined with a condition that excess weight is already making worse.

Working out your own BMI#

BMI is your weight in kilograms divided by your height in metres, squared. The NHS BMI calculator does this for you in seconds.

Here's a rough guide for common heights, so you can check where you stand without doing the sums:

So someone who's 1.70m tall and weighs 85kg has a BMI of about 29.4. They'd need a qualifying health condition to meet the 27 threshold, but wouldn't meet the plain 30 threshold without one.

If you're from a South Asian, Chinese, Black African or Black Caribbean background#

BMI alone can understate health risk in some ethnic groups. NICE guidance (PH46) recognises that people from South Asian, Chinese, Black African and Black Caribbean backgrounds face higher cardiometabolic risk at lower BMI values than the general population.

NHS England guidance reflects this with adjusted cut-offs. A BMI of 27.5 is treated as equivalent to the standard 30 threshold. A BMI of 25, with a weight-related condition, is treated as equivalent to the standard 27 threshold. Whether a service applies this adjustment depends on the clinician and the specific pathway, so it's worth asking directly.

NHS access versus private prescribing#

NICE assessed tirzepatide for NHS use in final guidance called TA1026. This sets out which patients the NHS should prioritise, based on BMI and the severity of weight-related conditions, within the budget and capacity NHS services actually have. NHS bodies in England must usually fund treatments covered by final NICE guidance within three months of that guidance being published.

In practice, NHS access runs through specialist Tier 3 weight management services, and waiting times vary a lot by area. Meeting the licensed BMI doesn't guarantee a place on an NHS programme straight away.

Private and online pharmacy prescribing uses the licensed thresholds rather than the NICE funding criteria, provided a prescriber confirms you meet them. At Totiva, Mounjaro pricing starts at £136.88 for the 2.5mg starting dose, rising through the higher doses as treatment progresses, up to £268.88 for 15mg. You can see current pricing and start a free online consultation through the weight loss service page.

If you're just under the threshold#

If you're a few kilos short, you have a few realistic options. You could lose that weight first through diet and activity changes. You could talk to your GP about your wider health risks, especially if you have a condition that might qualify you at BMI 27. Or you could check whether you meet the criteria for an alternative, like injectable Wegovy (semaglutide), which also uses the 30/27 BMI rule under its own licence.

It's worth noting that Totiva also offers Wegovy Tablets, an oral form of semaglutide. This is a different licensed product to the injection, and this article hasn't verified whether its weight-management BMI criteria match the injectable version exactly, so check the specific product information before assuming the same rules apply.

What else a consultation looks at#

BMI is the starting point, not the whole picture. A proper consultation also checks your weight history, your current medicines, and whether you are aged between 18 and 74, as Mounjaro is licensed for use within this age range. It asks about any personal or family history of medullary thyroid carcinoma (MTC), or the genetic condition MEN2 (Multiple Endocrine Neoplasia type 2), as these are contraindications to Mounjaro. It also asks about any history of pancreatitis, since this affects suitability.

It also asks about a current or recent eating disorder. The Mounjaro product information flags this as a factor requiring careful clinical assessment, and a prescriber will need to evaluate your individual circumstances before considering whether treatment is appropriate.

A consultation should include a video or phone conversation with a prescriber, not just a form you fill in online. This gives the clinician a proper chance to check your history and answer questions before anything is prescribed.

If your weight changes a lot during treatment, including dropping below the threshold that got you started, your prescriber will reassess whether continuing is still appropriate at your next review.