What weight do you have to be for Mounjaro?

Step 1: Where your BMI sits relative to the licensed criteria

The Mounjaro Summary of Product Characteristics (the definitive licensing document) sets out two routes in. A BMI of 30 or above qualifies you on body-mass index alone, provided there are no clinical contraindications. A BMI between 27 and 29.9 qualifies you if you have at least one weight-related health condition: type 2 diabetes, hypertension, dyslipidaemia, obstructive sleep apnoea, and cardiovascular disease are the most commonly cited examples. These thresholds apply to private prescribing; they reflect the medicine's UK marketing authorisation, which you can read in full via the NHS medicine information page for tirzepatide.

BMI is a useful screening number, nothing more. A prescriber also considers your medical history, current medicines, weight-related complications and whether the treatment is safe alongside anything else you are taking. Someone with a BMI of 31 and no comorbidities, and someone with a BMI of 28 and three weight-related conditions, may both be suitable, or either might not be, depending on the full picture. There is detail on what else feeds into eligibility on our Mounjaro weight eligibility overview.

Step 2: The ethnic-background adjustment and why it matters

Body-mass index was developed using data that does not represent all ethnic groups equally, and UK guidance recognises this. For people from South Asian, Chinese, Middle Eastern, Black African or African-Caribbean backgrounds, the same weight-related health risks tend to occur at a lower BMI. UK clinical guidance therefore applies thresholds that are 2.5 kg/m² lower: effectively BMI ≥27.5 instead of ≥30, and BMI ≥24.5 instead of ≥27 with a comorbidity. If you are close to a threshold and unsure whether an adjustment applies to you, this is exactly the kind of thing a prescriber can work through with you. You can read more about how age interacts with eligibility on our page covering the age requirements for Mounjaro.

It is worth being clear that these adjustments exist to improve health equity, not to lower the bar arbitrarily. The underlying principle is that clinical risk is being matched to clinical intervention, the numbers shift, but the reasoning is the same.

Step 3: NHS thresholds versus private prescribing, and why they differ

If you are hoping to access Mounjaro through the NHS, the criteria are currently more restrictive than the private licensed thresholds. NICE's technology appraisal TA1026, published in December 2024, recommends tirzepatide for adults with a BMI of 35 or above and at least one weight-related comorbidity, within a specialist weight-management service. You can check the exact wording in NICE's tirzepatide guidance (TA1026). NHS England is rolling out access in phases: since June 2025, people with a BMI of 40-plus and four or more qualifying conditions have been eligible; a second cohort covering BMI 35–39.9 with four or more conditions opened in June 2026; further cohorts follow into 2027.

Private prescribing follows the licensed SmPC criteria rather than the NICE commissioning thresholds. That means a prescriber working privately can consider the 27–29.9 BMI bracket, and is not restricted to the narrower NHS cohorts. For many people the NHS wait is long and the criteria do not yet include them, the minimum weight criteria explained page goes into further detail on this distinction. Cost context is available on our Mounjaro pricing page, including how Eli Lilly's September 2025 list-price increase affected the private market.

Step 4: What happens at the consultation itself

Meeting a BMI threshold gets you to the consultation. What happens next determines whether treatment is clinically appropriate. At nume, a GPhC-registered Independent Prescriber reads through your answers personally, the consultation does not pass through an algorithm. They look at BMI, any conditions you have, medications you take, relevant history and your goals. Identity and weight are verified, typically on a short video call. A decision is usually returned the same working day you submit, often in time for same-day dispatch if you order before 12pm (handy if you are juggling a school run and need the DPD tracking number before the afternoon). There are no subscriptions; every repeat order goes through a fresh clinical review, not an automatic renewal.

If you want to get a sense of where you stand before booking, the NHS BMI calculator gives you your number in under a minute. Whether it puts you at 27.5 or 34, the consultation is the right next step, our prescribers are the ones who can confirm whether treatment is right for you. You can also browse our weight-loss treatment options or read more about how tirzepatide compares to other medicines on our tirzepatide comparison page.