Wegovy's purpose: what it is licensed to do and why it works

Step 1, what Wegovy is actually licensed to treat

Wegovy holds a UK marketing authorisation for weight management alongside a reduced-calorie diet and increased physical activity. The licence covers adults with a body mass index of 30 or above, or 27 or above where at least one weight-related condition is present, for example high blood pressure, dyslipidaemia, obstructive sleep apnoea, or prediabetes. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance.

That scope matters. Wegovy is not licensed for people who simply want to lose a few pounds before a holiday, and the MHRA has been clear that GLP-1 medicines are not assessed for quick or cosmetic weight loss. It is a medicine for a medical condition, prescribed when the clinical picture supports it. Our Wegovy overview page sets out the full eligibility picture in detail.

One thing worth knowing early: Ozempic is also semaglutide, but it carries a separate licence for type 2 diabetes. The two products are not interchangeable for weight management purposes, and Ozempic should not be sought out as a weight-loss treatment.

Step 2, the mechanism: how semaglutide changes appetite

Semaglutide mimics a gut hormone called GLP-1 (glucagon-like peptide-1) that is released naturally after eating. By binding to GLP-1 receptors in the brain's appetite centres and in the gut wall, it slows gastric emptying and sends satiety signals that reduce how much you feel like eating. The effect is not a willpower top-up; it is a direct change to the biological signals that govern hunger.

This is why the trial results look the way they do. In the STEP 1 study, published in the New England Journal of Medicine, participants on semaglutide 2.4 mg lost an average of around 15% of body weight over 68 weeks. That figure comes from a setting with lifestyle support alongside the medicine, a useful reminder that Wegovy is designed as part of a broader effort, not a standalone solution.

For a practical sense of how to make the most of treatment once it starts, our guide to losing weight on Wegovy covers the dietary and activity habits that tend to produce the best results.

Step 3, the titration schedule and what the doses are doing

Treatment begins at 0.25 mg weekly. That first pen is not the therapeutic dose; its job is to let your body adjust gradually and reduce the chance of early nausea. The prescriber then moves the dose up through 0.5 mg, 1.0 mg and 1.7 mg stages, each held for roughly four weeks, before reaching the 2.4 mg maintenance level. The newer 7.2 mg dose approved by the MHRA follows the same patient-centred logic: start low, move slowly, let your system lead.

As of April 2026, a dedicated single-dose 7.2 mg pen (with a built-in covered needle that locks after use) is available. Trials at this dose reported around 20.7% average weight loss over 72 weeks, which narrows the gap with tirzepatide's results considerably. Whether a specific dose or pen format is right for you is confirmed at consultation; never assume a particular pen will be in your first order. The MHRA's announcement of the 7.2 mg pen has the full approval detail.

Side effects are mostly gastrointestinal (nausea, looser stools, indigestion) and they tend to be most noticeable in the first days after a dose increase, then settle. Most people find the slow titration makes them manageable. If you have questions about tolerability, our FAQs cover the side effects people ask about most often.

Step 4, NHS availability versus private prescription

NICE recommends Wegovy on the NHS (under guidance TA875) within specialist weight management services, for a maximum of two years, for adults meeting specific BMI and comorbidity thresholds. In practice, many people find NHS waiting lists are long and the criteria are strict. Private prescription is the alternative for those who do not meet current NHS criteria or cannot wait.

If cost is part of your thinking, our Wegovy price page explains what private treatment typically costs and what a legitimate fee should include, consultation, prescription, delivery and aftercare rather than just the pen. At nume, a clinician on our team reads every consultation the same day it arrives; a named prescriber, not software, makes the clinical call. Once approved, your order leaves our GPhC-registered pharmacy the same day if you submit before midday, useful if you want it before the working week ends. Delivery is free, next working day, in plain unbranded packaging via DPD.

Speak to our prescribers to find out whether Wegovy is clinically suitable for you. You can start your free consultation here, no referral needed, no waiting list. If you ever have questions about what the active ingredient actually is, our page on pure semaglutide explains exactly what goes into the medicine and what it means for your treatment. And when you finish a course or need to get rid of a used pen, our guide to disposing of Wegovy safely walks you through the correct steps.