BMI Requirements for Mounjaro in the UK: Who Is Eligible

The licence criteria every pharmacy starts from

Mounjaro is licensed in the UK for weight management in adults as an addition to a reduced-calorie diet and increased physical activity, with a starting BMI of:

• 30 or more (classed as obesity), or
• 27 to 29.9 (classed as overweight) with at least one weight-related health condition.

The Summary of Product Characteristics gives examples of the conditions that count: prediabetes, type 2 diabetes, hypertension (high blood pressure), dyslipidaemia (high cholesterol or triglycerides), obstructive sleep apnoea and cardiovascular disease. A pharmacy cannot prescribe below these thresholds under the licence, whatever its own policy says, so a provider that offers Mounjaro at a BMI of 25 to someone outside the NICE ethnic-background groups is one to treat with caution.

Lower thresholds for some ethnic backgrounds

NICE’s overweight and obesity guideline NG246, published in January 2025, states that people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds are prone to central adiposity and develop cardiometabolic risk at a lower BMI. It sets lower thresholds for these groups (overweight from BMI 23, obesity from BMI 27.5) and, for tirzepatide specifically, tells prescribers to reduce the usual BMI thresholds by about 2.5.

Conditions some pharmacies accept at a BMI of 27 to 29.9

The licence gives examples of weight-related conditions rather than a closed list, so pharmacies use their own criteria for what counts. The six named in the licence are accepted everywhere. The following are accepted by some providers and not others, usually case by case with evidence:

• Polycystic ovary syndrome (PCOS)
• Metabolic dysfunction-associated steatotic liver disease (previously called non-alcoholic fatty liver disease)
• Osteoarthritis or joint pain that a clinician links to weight
• Mobility limitation caused by weight
• Gastro-oesophageal reflux disease

If your eligibility depends on one of these, have the diagnosis in writing from a GP or specialist before the consultation. A pharmacy that accepts a self-reported condition without any evidence is not following the independent-verification requirement described next.

How your BMI is verified

On 4 February 2025 the General Pharmaceutical Council updated its guidance for pharmacies providing services online. Weight-management medicines were added to its list of high-risk medicines, and prescribers must now independently verify a person’s weight, height and BMI rather than rely on figures typed into a questionnaire. In practice this means a video consultation, a dated photograph of you on scales alongside a form of ID, or confirmation from your GP record. The guidance also requires two-way communication with the prescriber before a decision is made. A provider that approves you from a form alone, with no verification step, is not meeting the standard. Pharmacies also verify your identity; if you have no passport or driving licence, our ID check guide covers the alternatives.

You can check where you stand before booking with the Monj BMI calculator, which shows the standard and NICE-adjusted thresholds side by side.

NHS versus private eligibility

The licence criteria above are what private pharmacies work to. NHS access is governed by NICE technology appraisal TA1026 (December 2024), which recommends tirzepatide only for adults with a BMI of 35 or more and at least one weight-related condition, with the same 2.5-point reduction for the ethnic backgrounds listed above. NHS England is introducing it in phases, starting with people at the highest BMI with several conditions, so most people who meet the licence criteria will not currently qualify on the NHS. That difference in thresholds is the main reason private prescribing exists at the scale it does.

Eligibility at a glance

What happens to the BMI rule once you are on treatment

The licence thresholds are starting criteria. Nothing in the licence tells a prescriber to stop when your BMI falls below 30 or 27, and the clinical evidence favours continuing or tapering rather than stopping abruptly. But each pharmacy sets its own policy on how low it will prescribe to, and some also set a time limit, most often two years, which comes from an NHS funding rule rather than the licence. Some will continue at a BMI in the low 20s; others stop at 25 or 27, sometimes without warning.

This matters more than the starting criteria for anyone planning to keep weight off. Before you choose a pharmacy, ask for its maintenance BMI and time limit in writing. The maintenance pharmacies directory lists what each provider has stated, and its section on prescriptions being stopped explains what to do if it happens to you.

Changing pharmacy or restarting after a break

If you move to a new pharmacy mid-treatment, it will assess you against its own joining criteria, which for existing patients are usually more flexible than the starting thresholds, provided you can show your treatment history. Ask your current provider for a treatment summary first. If you have stopped for more than a few weeks, expect a new health assessment and a restart from a lower dose. Monj’s guides to switching pharmacy and restarting Mounjaro cover both in detail.