What BMI do you need for Mounjaro in the UK?
The UK licence for Mounjaro (tirzepatide) covers adults with a BMI of 30 or more, or 27 to 30 with a weight-related condition. The NHS in England sets higher bars: in 2026, a BMI of 35 or more plus at least 4 named conditions. For South Asian, Chinese, Black and some other backgrounds, NHS thresholds are 2.5 lower.
- Mounjaro, like every GLP‑1 medicine, is a prescription-only medicine in the UK. A healthcare professional must assess you before it can be prescribed.8
- BMI thresholds are points to discuss with a prescriber. Meeting one doesn't mean Mounjaro is right for you.
- To spot fake pens and illegal sellers, see Is it safe to buy Mounjaro online in the UK? The risks are in Guide 5: Side effects and risks.
What BMI does the Mounjaro licence set?
The licence, the MHRA's approval, covers a BMI of 30 or more, or 27 to under 30 with at least 1 weight-related condition.1
The MHRA is the UK medicines regulator. Examples of such conditions are high blood pressure, abnormal blood fats, sleep apnoea, heart disease, prediabetes and type 2 diabetes.1 The licence wording gives no separate figure for any ethnic group.1 BMI is your weight in kg divided by your height in metres squared.2
For someone 170 cm (5 ft 7 in) tall, a BMI of 30 is 86.7 kg (13 st 9 lb) and 27 is 78.0 kg (12 st 4 lb). That is our arithmetic.
What BMI does the NHS use for Mounjaro?
NHS thresholds are higher than the licence because the NHS brings Mounjaro in by priority, starting with the highest BMIs and the most conditions.
| Route | BMI, most people | BMI, South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean |
|---|---|---|
| UK licence (any prescriber) | 30 or more, or 27 to 29.9 with 1 condition | The same: the licence gives no separate figure |
| NHS England, from 23 Jun 2025 | 40 or more, with 4 of the 5 conditions | 37.5 or more, with 4 conditions |
| NHS England, from around Jun 2026 | 35 to 39.9, with 4 conditions | 32.5 to 37.4, with 4 conditions |
| NHS England, from around Mar 2027 | 40 or more, with 3 conditions | 37.5 or more, with 3 conditions |
| NHS Scotland (SMC) | 30 or more, with 1 weight-related condition | "a lower BMI cut-off may be more appropriate" |
From NICE TA1026 (England) and SMC2653 (Scotland), checked 12 Oct 2026.1,3,4 The 5 conditions are high blood pressure, abnormal blood fats, sleep apnoea, heart disease and type 2 diabetes.
At 170 cm, a BMI of 40 is 115.6 kg (18 st 3 lb), 37.5 is 108.4 kg (17 st 1 lb) and 35 is 101.1 kg (15 st 13 lb), by our arithmetic. The rules in Wales and Northern Ireland are in Can I get Mounjaro on the NHS?
With the NHS thresholds for your background. Free, no sign-up.
Why are the thresholds lower for some ethnic groups?
NICE says people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean background face health risks from weight at a lower BMI.
For these groups, NICE puts overweight at a BMI of 23 to 27.4 and obesity at 27.5 or more. Higher obesity classes are also 2.5 lower.5 NICE's Mounjaro guidance applies the same cut, so 37.5 instead of 40.3
BMI can mislead in people with a lot of muscle, and in people aged 65 and over.5 Waist size adds to the picture; see What is the waist-to-height ratio and how do I use it? Guide 1 explains the numbers: Weight and health.
- Stomach effects are very common. In the weight trials on the UK Mounjaro label, 25 to 29 in 100 people on 5 mg to 15 mg felt sick (nausea), against 9 in 100 on a dummy injection.6
- Gallstones are common (1 in 10 to 1 in 100) in the weight trials, and a swollen pancreas (acute pancreatitis) is uncommon (1 in 100 to 1 in 1,000), on the UK Mounjaro label. The MHRA strengthened the pancreatitis warning in January 2026.6,7
- Pregnancy and the pill. The MHRA says to stop Mounjaro at least 1 month before trying for a baby. It can make the contraceptive pill less reliable for 4 weeks after starting and after each dose rise.8
- Operations. Tell your anaesthetist you take it, because it slows how fast your stomach empties.8
Read the full picture
Related questions
Sources
- NICE. TA1026, section 2: marketing authorisation (2.1); list prices "excluding VAT; company communication" for a 4-week supply: £133.00 (2.5 mg), £180.00 (5 mg), £255.00 (7.5 and 10 mg), £330.00 (12.5 and 15 mg) (2.3); confidential commercial arrangement (2.4). Price list updated 1 Sep 2025. nice.org.uk
- NHS South West London Integrated Care Board. Prescribing weight loss medications in south west London: tirzepatide (Mounjaro). Page updated 30 Jul 2026. southwestlondon.icb.nhs.uk
- NICE. Tirzepatide for managing overweight and obesity (TA1026), section 1, Recommendations and "What this means in practice". Published 23 Dec 2024, last updated 1 Sep 2025. nice.org.uk
- Scottish Medicines Consortium. Tirzepatide (Mounjaro) SMC2653: "accepted for restricted use within NHSScotland"; restriction "adults with BMI ≥30 kg/m2* and at least one weight-related comorbidity" (*lower cut-off may be more appropriate for some minority ethnic groups). Advice published 10 Jun 2024. scottishmedicines.org.uk
- NICE. Overweight and obesity management (NG246), recommendations 1.9.11 to 1.9.13. Published 14 Jan 2025, last updated 8 Jan 2026. nice.org.uk
- Eli Lilly. Mounjaro KwikPen summary of product characteristics (UK SmPC), date of revision 29 Aug 2026, sections 4.1, 4.2, 4.4, 4.5, 4.6 and 4.8 (Table 1). UK label. medicines.org.uk (emc)
- MHRA. MHRA updates guidance for GLP-1 prescribers and patients (acute pancreatitis). Press release, 29 Jan 2026. gov.uk
- MHRA. GLP-1 medicines for weight loss and diabetes: what you need to know. Guidance, published 5 Jun 2025, last updated 5 Feb 2026. gov.uk
Last checked 12 Oct 2026 · Next review due 12 Oct 2027 · Report an error
How this answer was made. Written by the GLP Guidebook team from the sources above, all checked on 12 Oct 2026. Prices are official list prices or NHS charges, never a seller's price, and we don't name or rank sellers. Figures marked as our arithmetic are worked out from those sources. It's general information, not medical advice. Talk to a GP, pharmacist or other qualified prescriber before starting, stopping or changing any medicine. How we write