What does your BMI have to be to get Mounjaro?

What the official guidance actually says about BMI for Mounjaro

The clearest starting point is the licensed indication. Eli Lilly's UK authorisation for Mounjaro (verified in the product's Summary of Product Characteristics and summarised on the NHS tirzepatide medicine page) covers adults with a BMI of 30 kg/m² or higher, and adults with a BMI of 27 kg/m² or higher who have at least one weight-related comorbidity. Those comorbidities include, among others, prediabetes, type 2 diabetes, hypertension, dyslipidaemia (high cholesterol or triglycerides), obstructive sleep apnoea, and osteoarthritis.

NICE's TA1026 recommendation, published in December 2024, sits on top of that licence. For NHS use, NICE recommends tirzepatide only for adults with a BMI of 35 or above combined with at least one weight-related condition, a considerably higher bar than the private licence. The private route follows the manufacturer's licensed indication, so the lower thresholds of 30 and 27 apply. That distinction matters for anyone weighing up the specific BMI needed for Mounjaro through a private clinic versus an NHS pathway.

One further nuance worth knowing: UK clinical guidance recognises that the health risks of excess weight occur at lower BMI values for people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds. For those groups, both the NICE thresholds and standard clinical practice typically apply BMI cut-offs that are 2.5 kg/m² lower across the board, and you can read more about what BMI to have for Mounjaro given these adjustments and the wider eligibility picture.

What counts as a qualifying condition at a BMI between 27 and 29.9

If your BMI sits in the 27–29.9 range, a qualifying condition is not a technicality, it is a genuine clinical requirement. The conditions that count are those directly linked to excess weight and likely to improve with sustained weight loss. High blood pressure is among the most common; so is type 2 diabetes or prediabetes, obstructive sleep apnoea, and raised cholesterol. Osteoarthritis of weight-bearing joints is also recognised.

A diagnosis does not have to be recent or formally coded by your GP, but a prescriber will want to understand your medical history. That is why the assessment process looks at more than a single number, your comorbidities, their severity, other medications, and contraindications all feed into the prescriber's decision. Conditions such as a personal or family history of medullary thyroid carcinoma, or a history of pancreatitis, would require careful discussion before any prescription is issued.

If you are unsure whether your BMI qualifies you at a given BMI point, the NHS BMI calculator is a useful starting reference before you speak to a clinician. It takes height, weight and age, and gives you a figure to work with ahead of your consultation.

NHS eligibility versus private eligibility: two different sets of rules

The NHS rollout of Mounjaro operates under a phased commissioning system that is considerably more restrictive than the private licence. As of summer 2026, NHS England's first cohort requires a BMI of 40 or above combined with four or more of five specified conditions (high blood pressure, dyslipidaemia, obstructive sleep apnoea, cardiovascular disease, and type 2 diabetes). A second cohort, activated in June 2026, extends access to people with a BMI of 35–39.9 with four or more of those same conditions.

Most people who contact a private service like our weight management service do not meet those NHS thresholds. They are asking a different question: do I meet the licensed private criteria? The answer, if BMI is 30 or above (or 27 with a comorbidity), is that a consultation is worth having. Meeting the threshold opens the door to assessment; it does not guarantee a prescription. Our prescribers at our clinical team read every consultation personally (not software) and make a clinical judgement on each person's individual picture. For a fuller breakdown of how high your BMI needs to be for Mounjaro across both NHS and private routes, we have covered the detail separately.

One thing that sometimes catches people out: GP practices can now prescribe Mounjaro under the 2026/27 GP contract, but participation is voluntary and varies by area. Some practices are prescribing; many are not yet. Waiting times for specialist weight management services (the route to Wegovy on the NHS) remain long in most areas. Private assessment can happen the same day you apply. If you order before midday on a working day and a prescriber approves your treatment, your prescription is dispatched the same day and arrives via tracked DPD the next working day.

What to expect if your BMI is right at the threshold

A BMI of exactly 30 (or 27 with a documented comorbidity) does qualify you under the private licence. In practice, prescribers at the lower end of the eligible range look closely at the overall clinical picture. Is the weight-related condition well-managed or worsening? Are there medications or health factors that might alter the risk-benefit calculation? These questions matter more when the BMI figure is borderline than when it is well above the threshold.

There is also the question of how accurately your BMI was measured. A bathroom scale read mid-afternoon after lunch tells a slightly different story from a morning weight taken consistently over several days. Muscle mass, hydration status and the time of day all move the figure. This is part of why live weight verification forms part of our clinical process, a prescriber seeing a verified, current weight makes a better-informed decision than one relying on a self-reported figure from six months ago. More detail on exactly what BMI you need for Mounjaro and how it's verified is covered in our related guide. If you have read this and think you might be eligible, speak to our prescribers through a free consultation, it costs nothing to find out.