How overweight do you need to be for Wegovy — and does your BMI tell the whole story?

You've looked up your BMI and you're wondering whether it's enough

Say you've calculated your BMI as 31. You feel the weight in your knees, your sleep is poor, and your GP mentioned your blood pressure is creeping up. You've read about Wegovy and you want to know if you qualify. The short answer is: that BMI puts you squarely within the licensed threshold for semaglutide in the UK. Whether a prescription is right for you is a different question, one only a clinical assessment can answer.

The licensed eligibility for Wegovy, as set out by the MHRA and supported by NICE's appraisal of semaglutide for weight management (TA875), draws two groups. First: adults with a BMI of 30 or above, regardless of other conditions. Second: adults with a BMI between 27 and 29.9 who have at least one weight-related comorbidity, things like type 2 diabetes, obstructive sleep apnoea, raised cholesterol, hypertension, or established cardiovascular disease. If you sit in the 27–29.9 bracket without any of those conditions, semaglutide isn't currently licensed for you in the UK.

One detail that often surprises people: the 2.5 kg/m² adjustment. Clinical guidance recognises that cardiometabolic risk can be higher at a lower BMI in some ethnic groups. For people of South Asian, Chinese, Middle Eastern, Black African or African-Caribbean backgrounds, the thresholds shift down, so 27.5 effectively becomes the new 30, and 24.5 the new 27. Your prescriber applies these adjustments as part of a proper assessment. You can use the NHS BMI calculator to get your number before consulting.

The NHS route versus a private prescription, the thresholds aren't the same

Here's where people get confused. You might meet the licensed BMI threshold and still find you don't qualify on the NHS. That's because NICE's guidance for NHS use (TA875) is stricter than the medicine's marketing authorisation. On the NHS, Wegovy is currently commissioned only through specialist weight management services, requires a BMI of at least 35 (or 32.5 for certain ethnic backgrounds) alongside a weight-related comorbidity, and the treatment duration is capped at two years.

If your BMI is 30 and you have no other conditions, you meet the licensed threshold but fall outside NHS commissioning criteria. For many people, a private prescription is the route that actually opens up. Through a regulated online pharmacy like our Wegovy service, the threshold is the licensed one (BMI ≥30, or ≥27 with a qualifying condition) and a GPhC-registered Independent Prescriber reviews your consultation the same day, not a piece of software. That's a meaningful difference when you've been researching this for months and want a straight answer quickly.

It's also worth knowing that how overweight you need to be to use Wegovy practically speaking involves more than a number, your prescriber is looking at your health history, current medications, and whether any contraindications apply. The assessment is thorough precisely because this is a prescription medicine, not a supplement.

What happens if your BMI is just below the threshold

A BMI of 28, no diagnosed conditions. You're in a frustrating middle ground. Semaglutide isn't licensed for you at that point, and a responsible prescriber won't issue it off-label for weight loss, nor should they. If you're wondering whether Wegovy might be an option when you're only slightly overweight, that page explains in detail why the current licensed thresholds are set where they are and what your realistic options look like. It's also worth exploring the wider range of weight management approaches available, because the threshold exists for a clinical reason: the trials that generated the evidence, and shaped the NICE appraisal, enrolled participants within those parameters. Prescribing outside them would be working without that evidence base.

The NHS England guidance on weight management injections is clear that these are not medicines assessed for cosmetic use. They're for people whose weight is genuinely affecting their health. That framing isn't meant to be discouraging, it's the honest context that helps you understand why the threshold is where it is, and whether another conversation with your GP about your overall health picture might shift your position. A condition that hasn't been formally diagnosed can sometimes change the eligibility calculation once it is.

If you're close to the threshold or uncertain where you sit, you can read a detailed guide to how overweight you have to be for Wegovy to help you prepare for that conversation. And if you've already confirmed you meet the criteria, understanding what private treatment costs is a reasonable next step, the price includes the prescription, aftercare, and delivery with no separate fees to add up. Start your free consultation when you're ready, and a prescriber will review your details the same day.