What weight do you need to qualify for weight loss injections?

Why your BMI matters more than the number on the scales

If you've been searching for a specific weight that qualifies you, the honest answer is that there isn't one universal figure. Eligibility is based on BMI (body mass index, which relates your weight to your height) rather than weight alone. A person who is 160 cm tall and weighs 77 kg has a BMI of just over 30. Someone 185 cm tall at the same weight sits below 23. Same number on the scales; entirely different clinical picture.

The NHS BMI calculator is a useful first check, and the thresholds set out in the UK product licences for Mounjaro (tirzepatide) and Wegovy (semaglutide) are clear: BMI 30 or higher for weight management, or 27–29.9 if you have at least one weight-related condition. You can find the detailed licence criteria on the NHS tirzepatide medicines page.

If you're close to the threshold, it's worth measuring your height carefully before calculating. Many people are surprised, in both directions. And if you feel frustrated that eligibility comes down to a formula rather than how your weight is actually affecting your life, that frustration is entirely reasonable. BMI is an imperfect proxy; prescribers know that, which is why the number opens the conversation rather than closing it.

The conditions that can lower the bar

A BMI between 27 and 29.9 isn't a flat refusal. Both Mounjaro and Wegovy are licensed for this range when a qualifying weight-related health condition is present. The conditions that count include type 2 diabetes, pre-diabetes, high blood pressure, raised cholesterol or triglycerides, obstructive sleep apnoea, and cardiovascular disease, among others, the full list is set out in the medicine's licence and assessed by your prescriber.

Ethnic background also affects the thresholds under UK clinical guidance. For people of South Asian, Chinese, Middle Eastern, Black African or African-Caribbean backgrounds, the relevant BMI thresholds are 2.5 kg/m² lower throughout, reflecting research on how body composition and metabolic risk differ across populations. NICE's appraisal of tirzepatide (NICE TA1026) set this adjustment into its recommendations, and it applies to private prescribing as well as NHS routes.

Worth noting: the qualifying condition doesn't need to be severe or long-standing. Mild hypertension managed by lifestyle, or a borderline HbA1c, can be enough, the prescriber interprets the full picture.

What a clinical assessment looks at beyond BMI

Meeting the BMI threshold opens the door; it doesn't hand you a prescription. A prescriber reviewing your consultation is also checking whether anything makes these medicines unsuitable for you specifically. A history of pancreatitis, certain thyroid conditions, or a diagnosis of MEN2 (multiple endocrine neoplasia type 2) are among the contraindications listed in the medicines' licensed information. Pregnancy, breastfeeding, or actively trying to conceive are also reasons these medicines are not recommended.

Current medicines matter too. Some interact with the way GLP-1 and dual GIP/GLP-1 medicines slow digestion, oral contraceptives and certain diabetes medications are among the things a prescriber will factor in. The NHS England guidance on weight management injections covers these considerations in detail.

At nume, every consultation is personally read by a GPhC-registered Independent Prescriber before any decision is made. If you're wondering which injection might suit you, that clinical review is where the real answer comes from, our prescribers look at the whole picture, not just a number.

The difference between private eligibility and NHS criteria

NHS access to these medicines follows stricter, phased criteria than the private licence. For Mounjaro on the NHS, NICE TA1026 currently requires a BMI of 35 or above alongside multiple qualifying conditions, and the rollout is staged, meaning many people who meet the BMI threshold will still be in a waiting phase. That gap is why most people asking this question are looking at private routes.

Private eligibility follows the licensed thresholds described above: BMI 30-plus, or 27-plus with a qualifying condition. There's no referral needed and no waiting list at a regulated private pharmacy. The cost of treatment is a separate consideration, you can explore what's included in a nume consultation on our treatment page, where current pricing is shown transparently. The medicines themselves are the same ones dispensed by NHS pharmacies; what differs is the access route.

If you're still getting to grips with how a weight loss injection actually works, our overview of the weight loss injections licensed in the UK lays out both options clearly. If you want to understand the current landscape in more detail, our guides covering the two weight loss injections available and the three weight loss injections now on the market walk through how each one works and who it suits. And if you've heard about newer options recently, the latest approved injections page covers what's changed.

Ready to find out whether you're clinically suitable? Speak to our prescribers through a free consultation, reviewed the same day, with no obligation.