The BMI Required for Mounjaro — and What the Number Alone Won't Tell You

The myth: if your BMI is above 30, you qualify for Mounjaro

This is the most common misread of the eligibility rules, and it leads to a lot of disappointment. The licensed minimum BMI of 30 is a necessary condition, not a sufficient one. The UK licence for tirzepatide covers adults with a body mass index of 30 or higher, or 27 or higher where a weight-related condition is already present. Those conditions include type 2 diabetes, prediabetes, high blood pressure, dyslipidaemia (raised cholesterol or triglycerides) and obstructive sleep apnoea, among others. NHS guidance on tirzepatide sets this out clearly.

What the licence cannot tell you is whether Mounjaro is safe for you specifically. Certain conditions (a history of pancreatitis, medullary thyroid carcinoma, the rare inherited condition MEN2) mean tirzepatide is not appropriate regardless of BMI. Pregnancy, breastfeeding and trying to conceive all rule it out. The prescription-only status exists precisely because these individual factors matter and require a clinician to weigh them up, not a calculator.

So: a BMI of 32 with no comorbidities probably meets the threshold on paper. A BMI of 32 combined with a relevant contraindication does not result in a prescription. The number is the floor, not the ceiling of the assessment.

The 27 threshold, and when it applies

If your BMI sits between 27 and 29.9, you are not automatically excluded. The lower threshold exists for people who carry that weight alongside a health condition that makes it clinically significant, hypertension, raised blood glucose, sleep apnoea, cardiovascular disease, osteoarthritis. The logic is straightforward: at a BMI of 28, the health burden for one person may be negligible; for another, it may already be driving meaningful risk. The comorbidity criterion captures that distinction.

It is also worth knowing that UK guidance recognises different risk profiles across ethnic backgrounds. For people of South Asian, Chinese, Middle Eastern, Black African or African-Caribbean heritage, the same clinical thresholds apply at a BMI that is 2.5 kg/m² lower. In practice that means the main eligibility threshold shifts to roughly 27.5 instead of 30, and the lower comorbidity threshold shifts to roughly 24.5. NICE's technology appraisal of tirzepatide (TA1026) sets out the adjusted thresholds for NHS purposes, and the same principle applies to private prescribing under the licensed indication.

You can check where your own BMI sits using the NHS BMI calculator, though the number you get there is genuinely just the starting point. Our full breakdown of Mounjaro requirements covers what else the prescriber considers beyond the BMI figure.

NHS thresholds vs. private prescribing, they are not the same thing

A point that causes real confusion: the NHS operates a phased rollout for tirzepatide that is considerably more restrictive than the medicine's licence. As of mid-2026, NHS access generally requires a BMI of 35 or above with four or more specific comorbidities from a defined list. A second cohort, covering BMI 35–39.9 with four or more conditions, opened in June 2026. Further cohorts are planned through 2027, gradually expanding access. Most people who meet the licensed private eligibility criteria (BMI ≥30) do not yet meet the NHS criteria, and those who do often face long waiting lists.

Private prescribing through a regulated pharmacy follows the licensed indication, not the NHS phasing. That is why the two routes have such different eligibility profiles, one is rationed by capacity and cost to the health service, the other is governed by the medicine's clinical licence and individual suitability. For context on how UK private treatment is priced, our overview of Mounjaro UK pricing explains what has changed and what a legitimate private prescription typically covers.

If you are currently on Mounjaro through another provider and considering moving, the full picture of what prescribers look for at each stage is worth reading before you make any changes.

What the consultation actually covers (beyond the BMI check

At nume, every consultation is read the same day by a GPhC-registered Independent Prescriber) a real clinician, not automated software. The BMI question takes about thirty seconds of that review. The rest covers your medical history, current medicines (some interact with tirzepatide in ways worth discussing, including oral contraceptives during the first weeks of treatment), any conditions that would affect suitability, and your general health goals. People sometimes ask whether supplements like apple cider vinegar are safe to take alongside Mounjaro, and that is exactly the kind of question the prescriber can address at this stage. Live weight verification on video is part of the process, as is photo-ID check and, where appropriate, a Summary Care Record review.

Once approved, treatment is dispatched the same day for orders placed before noon on weekdays, arriving the next working day via tracked DPD in plain packaging. The pen itself needs to go straight into the fridge door when it arrives, standard refrigeration between 2°C and 8°C, the same as most injectable medicines. For practical storage specifics, the Patient Information Leaflet that comes with your pen has the exact detail, including the limited window for room-temperature use when travelling.

If any of this raises questions about whether you'd be suitable, our guide to HbA1c and diabetes-related criteria covers the overlap between weight management and blood glucose conditions in more depth. And if you want to understand the broader landscape of weight-loss treatment options before committing to a consultation, that is a reasonable place to start too.