Wegovy weight loss results: what clinical trials actually found

You've seen the headline figure — here's what it means in practice

Imagine you weigh 100kg when you start Wegovy. A 15% average reduction, as seen in the STEP 1 trial, would translate to roughly 15kg over just over a year. But averages obscure the real picture. In STEP 1, participants at the top of the distribution lost considerably more; others closer to the bottom lost less. You can read more about how Wegovy results vary across the full range of trial participants on our dedicated results page, which puts those numbers into context.

What the trial does tell us clearly is that semaglutide 2.4mg produced roughly three times the weight loss seen in the placebo group over 68 weeks, with participants following a structured lifestyle programme alongside injections. That structure matters. The medicine reduces appetite and slows the rate at which your stomach empties; it does not replace dietary change or movement. Trial participants who engaged consistently with both tended to sit higher in that distribution.

The NHS semaglutide medicines page explains in plain language how semaglutide works and what to expect, and it is worth reading before you start any treatment. For a closer look at how results break down week by week, our page on Wegovy weight loss results per week maps the typical trajectory through the dose escalation stages.

The 7.2mg dose changed what's possible

When semaglutide 2.4mg was the ceiling, tirzepatide's trial results put it clearly ahead. The MHRA's approval of a 7.2mg Wegovy maintenance dose in early 2026 narrowed that gap. Trials at the higher dose reported average weight loss of around 20.7% over 72 weeks, a result that approaches what the highest tirzepatide dose achieved in the SURMOUNT-1 programme.

The 7.2mg pen received dedicated single-dose approval on 14 April 2026. It works via the same GLP-1 receptor pathway as 2.4mg but delivers a larger weekly dose, with the same titration requirement: you still start at 0.25mg and increase gradually under prescriber guidance. Jumping to the highest dose from the outset would mean much more nausea with no clinical benefit. The timeline for Wegovy to take effect explains why the slow escalation exists and what you can reasonably expect to feel in the early weeks.

What actually arrives, when you go through a regulated UK pharmacy, is a pre-filled weekly injection pen, tracked by DPD, in plain unbranded packaging. The pen is pre-set to your current dose; there's nothing to draw up or measure. Whether your prescriber is working towards 2.4mg or 7.2mg as your maintenance target is something they confirm at each clinical review.

What shapes your individual weight loss results on Wegovy

Trial averages are a starting point, not a promise. Several factors influence where any individual ends up within that spread of results.

Starting BMI plays a role: people with a higher baseline weight tend to lose more in absolute kilograms, though the percentage reduction can be similar. Consistency with the lifestyle component matters significantly, the trial protocol included dietary advice and activity targets, not injections alone. Dose reached is another variable: those who tolerate escalation to maintenance dose tend to see better outcomes than those who plateau at a lower rung because of side effects.

There is also the question of early response. Some evidence suggests that people who do not lose at least 5% of body weight after six months at their highest tolerated dose are less likely to benefit substantially from continuing. NICE's appraisal of semaglutide (TA875) notes this as a clinical review point. It is one reason our prescribers re-assess before every repeat order rather than simply renewing automatically.

For a comparison of how Wegovy and tirzepatide (Mounjaro) results stack up against each other in the published evidence, the semaglutide weight loss results page draws those lines clearly. Cost context, for anyone weighing up whether private treatment makes sense, is covered separately on our treatment options page.

What happens at one month, and when most people notice a real shift

The first month on Wegovy is mostly about tolerating the 0.25mg starting dose. It is a small dose by design, your system is adjusting, not yet losing weight at pace. Most people notice modest appetite suppression and some gastrointestinal settling-in effects: nausea is the most commonly reported, usually peaking in the days after an injection and easing by mid-week.

Meaningful weight loss results tend to become visible from around weeks four to eight, as the dose increases. The one-month Wegovy results page gives realistic figures for that early period so you know what to compare against. Most of the significant reduction builds over months three to six and beyond, with the bulk of the STEP 1 trial's 15% average accruing through the mid-trial period rather than the first few weeks.

By week five, many people report their hunger patterns feel genuinely different, not suppressed to nothing, but quieter. Our page on week five results looks at what that inflection point typically looks like. If results have stalled at a later stage, or you want to understand the broader landscape of treatment options, the weight loss treatments overview covers the full picture.