How effective is Wegovy? What the trial data shows

You've seen the headline percentage, here's what it actually means for someone starting treatment

Picture someone who weighs 100 kg stepping onto a scale at the end of a 68-week trial. If their experience matched the STEP 1 average, they would have lost around 15 kg. That is not a modest change: it is the kind of reduction that meaningfully lowers blood pressure, eases joint load and improves blood-sugar control. The trial enrolled adults who did not have diabetes, used a calorie-reduced diet and increased activity alongside the medicine, and followed a dose-escalation schedule starting at 0.25mg and rising to 2.4mg. Those conditions matter, Wegovy is licensed as an adjunct to lifestyle changes, not a standalone intervention, and the trial results reflect that combined approach. The NHS medicines page on semaglutide sets out how the medicine works and what to expect during treatment. The practical check worth doing before you start anything: weigh yourself at the same time of day each week, write it down, and track the trend rather than the day-to-day noise. One minute, once a week. If you would like to see how those results translate into real-world experience, wegovy patient reviews collected from people on treatment give a grounded sense of what progress can look like week to week.

The 2026 dose increase and what it means for the effectiveness ceiling

Until early 2026, 2.4mg was the maximum weekly maintenance dose. The MHRA changed that picture on 12 January 2026 when it approved a 7.2mg maintenance dose, with a dedicated single-dose pen following on 14 April 2026. Trial data at 7.2mg showed average weight loss of around 20.7% over 72 weeks, a substantial step up from the 2.4mg results and one that narrows the gap with tirzepatide (Mounjaro) at its highest dose. The 7.2mg licence applies to adults with a BMI of 30 or above; it is not approved for lower BMI thresholds or for the cardiovascular indication. Whether this higher dose is appropriate for any individual is a clinical decision. If you are curious about how the 25mg oral Wegovy tablet compares or want detail on what drives the weight-loss results across doses, both questions have their own answers on site. Titration still begins at 0.25mg regardless of which maintenance dose is the eventual target.

Why results differ between people, and what the evidence says about longer-term use

A clinical trial average is a useful benchmark, not a forecast for any one person. In the STEP 1 data, around one in three participants achieved weight loss of 20% or more at 2.4mg, while others lost considerably less. Starting BMI, adherence to lifestyle changes, individual biology and how long treatment runs all pull the outcome in different directions. One frequently asked question is whether the medicine stops working over time. Whether Wegovy's effectiveness reduces with continued use is a distinct topic, and the evidence there is worth reading separately. What the extension data clearly shows is that stopping treatment typically leads to weight regain, which is why the question of how long to continue is taken seriously at prescriber level. The NICE technology appraisal for semaglutide (TA875) recommends continuing treatment only if at least 5% weight loss has been achieved after six months at the maintenance dose, a threshold that acts as a built-in effectiveness check. On the semaglutide overview page you will find a broader look at the medicine's mechanism and licensed uses in the UK. For those weighing up whether Wegovy is the right option, our treatment overview covers what the consultation process involves. Understanding the cost picture for Wegovy in the UK is also part of a sensible decision, it is covered plainly, without glossing over what private treatment involves. If you find the evidence compelling and want a clinical view on whether it applies to your situation, speak to our prescribers through a free consultation, reviewed the same day by a GPhC-registered Independent Prescriber, not automated software.