Results & Expectations

Wegovy Results

Learn what results to expect from Wegovy, including weight loss timelines, average progress, and how outcomes typically develop over time.

Whether you are weighing up Wegovy or trying to gauge your own results against the published data, this guide breaks down the clinical-trial weight-loss numbers for semaglutide 2.4mg in adult weight management. The figures come from the STEP trial programme — the most important being STEP 1 — and the head-to-head SURMOUNT-5 trial against tirzepatide. LetsLoseWeight is an independent comparison site; we do not prescribe medication, and individual results vary widely.

The headline number from STEP 1

The pivotal trial for semaglutide 2.4mg in weight management was STEP 1, published in the New England Journal of Medicine in 2021. Around 1,961 adults with overweight or obesity but without type 2 diabetes were randomised to placebo or semaglutide 2.4mg for 68 weeks. All participants followed lifestyle interventions including a reduced-calorie diet and increased physical activity (Wilding et al., NEJM 2021).

Average weight loss at 68 weeks:

Group Average weight loss Average weight loss in kg (≈)
Placebo 2.4% ~3 kg
Semaglutide 2.4mg 14.9% ~15 kg

The mean starting weight in the trial was around 105 kg. As with Mounjaro, personal results scale roughly with starting weight — someone smaller should not expect to lose 15kg, but a similar percentage is plausible.

What the spread looked like

The 14.9% trial average compresses a wide spread of outcomes. In STEP 1:

  • Around 86% of participants on semaglutide lost at least 5% of their starting weight
  • Around 69% lost at least 10%
  • Around 51% lost at least 15%
  • Around 32% lost at least 20%

But also:

  • Around 14% did not lose 5% — non-responders even at the full maintenance dose

The implication: the majority of patients lose a clinically meaningful amount, a substantial proportion lose 15% or more, and a meaningful minority lose little.

Trial population — who was studied

STEP 1 enrolled adults with the following profile:

  • Mean age around 46 years
  • Mean BMI around 38 kg/m²
  • Mean starting weight around 105 kg
  • Around 75% female
  • Without type 2 diabetes

A separate trial — STEP 2 — studied semaglutide in people with type 2 diabetes. Average weight loss was somewhat smaller (around 9.6% at the 2.4mg dose), which is typical of obesity-treatment trials in patients with diabetes.

Beyond weight — what else changed

STEP 1 also reported on cardiometabolic markers. By 68 weeks, the semaglutide group showed:

  • Reductions in waist circumference averaging around 13 cm
  • Improvements in blood pressure — typical reductions of 5–6 mmHg systolic
  • Improvements in fasting blood sugar even in non-diabetic participants
  • Improvements in lipid panel — including triglycerides and HDL cholesterol
  • Improvements in physical function scores
  • Reductions in C-reactive protein, a marker of inflammation

The cardiovascular benefits of semaglutide more broadly were also studied in the SELECT trial, which showed a 20% reduction in major cardiovascular events in adults with established cardiovascular disease and overweight/obesity (Lincoff et al., NEJM 2023).

Mounjaro vs Wegovy — the head-to-head

The SURMOUNT-5 trial in 2025 was the first head-to-head comparison of tirzepatide and semaglutide for weight management. After 72 weeks, average weight loss was greater with tirzepatide than with semaglutide, with both producing clinically meaningful weight loss (Aronne et al., NEJM 2025).

That does not mean Wegovy is now the wrong choice. Some patients lose more on semaglutide than on tirzepatide; tolerability differs; and Wegovy remains a strong, well-evidenced option, particularly for patients who tolerate it well, who have specific reasons to avoid Mounjaro, or for whom the cost balance differs. See our Mounjaro vs Wegovy UK comparison.

What about 1.7mg as a maintenance dose?

For patients who do not tolerate the full 2.4mg maintenance dose, the SmPC permits 1.7mg as a long-term maintenance dose. Trial data suggests this delivers slightly lower average weight loss than 2.4mg — around 12–13% rather than 14.9% in similar populations — but is a reasonable option for those for whom 2.4mg is intolerable.

For more on dosing, see our Wegovy dosing guide.

Real-world results vs trial results

Real-world data on semaglutide tends to show slightly lower average weight loss than the STEP trials. This is normal across most medicines: trial conditions are more controlled, monitoring is more intensive, and trial populations are more selected. As a rough rule of thumb, real-world averages tend to be 70–85% of trial averages.

For semaglutide 2.4mg, where the trial average was around 15%, real-world averages are often in the 11–13% range. Still substantial, but a step below the headline figure.

What this means for setting expectations on Wegovy

A reasonable, evidence-based set of expectations:

  • Most patients on Wegovy lose a clinically meaningful amount — typically 10–15% of starting weight at the maintenance dose, over 12–18 months
  • A substantial minority lose 15% or more — particularly those who tolerate the full 2.4mg dose and engage strongly with lifestyle changes
  • A meaningful minority lose little (~14% non-responders at full dose)
  • Real-world results tend to be a bit lower than trial results

When results don't match expectations

A reasonable benchmark from clinical practice is at least 5% weight loss by 12 weeks at the 2.4mg maintenance dose. If your trajectory is below that, possible reasons to discuss with your prescriber:

  • Adherence — keeping weekly injections on schedule
  • Whether the dose can be tolerated up to 2.4mg if you are still at a lower step
  • Other medicines that promote weight gain (some antidepressants, some antipsychotics, some diabetes medicines)
  • Untreated medical conditions (hypothyroidism, sleep apnoea, depression)
  • Calorie reduction — the medicine reduces appetite but cannot fully override active overconsumption

For more, see our what affects results guide and plateau guide.

What happens after stopping Wegovy

The STEP 1 trial extension followed participants for a year after stopping semaglutide and lifestyle interventions. By 12 months, on average, participants had regained around two-thirds of the weight they had lost (Wilding et al., 2022).

This is consistent with the broader picture of obesity as a chronic condition — the underlying biology that drives weight gain does not disappear after a course of treatment. It is one of the reasons NICE TA875 caps NHS treatment at two years and increasingly the question of long-term continuation is being discussed in clinical practice.

Frequently asked questions

Should I expect to lose 15% of my starting weight on Wegovy?
That is the trial average at the 2.4mg dose. Many patients lose more, many lose less, and real-world averages tend to be a bit lower than the trial figure. Expect a range of 10–15% on full dose, recognising the spread is wide.

How quickly should I see Wegovy results?
Most patients see appetite changes within 1–2 weeks and measurable scale changes by weeks 5–8. The steepest weight-loss curve is typically months 4–9 once the 2.4mg maintenance dose is reached. See our when do you see results guide.

Why might my results be lower than the trial average?
Real-world results tend to run lower than trial results across most medicines. Other factors include not reaching the 2.4mg dose, less consistent diet and activity changes, untreated medical conditions, and individual biological variability.

Can I expect to keep losing weight beyond 12 months?
Some additional weight loss often continues into the second year, but at a much slower rate. Most patients stabilise at a new lower set point by 12–18 months.

Is Wegovy still worth taking now that Mounjaro shows greater average weight loss?
For many patients, yes. Individual response varies; some lose more on Wegovy than on Mounjaro. Wegovy also has a longer track record (licensed earlier, more long-term data) and may be preferable on cost, tolerability, or specific clinical grounds. The right choice is a clinical decision.

Next steps

Sources

This guide is for general information only and is not a substitute for professional medical advice. Individual results vary. Talk to a qualified prescriber about realistic expectations for your situation.

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Wegovy Results UK: STEP Trial Data and Expected Loss | LetsLoseWeight