What does the Wegovy weight loss graph actually tell you?

What does the shape of the Wegovy weight loss curve actually mean?

The STEP 1 trial, published in the New England Journal of Medicine, tracked 1,961 adults with obesity or overweight over 68 weeks. The graph it produced has a distinctive shape: weight falls quickly in the first few months, then the rate of loss slows and levels into a gentler decline before largely plateauing around weeks 60–68.

That shape is not a flaw. It reflects biology. In the early months the appetite-suppressing effect of semaglutide is strongest relative to the body's existing set-point; as weight falls, the body adapts and the weekly reductions become smaller. This is why the curve flattens rather than continuing to drop in a straight line.

For most people reading the graph, the headline number is around 15% average body-weight reduction at 2.4mg. On someone starting at 100kg, that is roughly 15kg. But the graph also shows something the headline figure obscures: a meaningful spread. Some participants lost considerably more; others lost less. The average sits in the middle of a wide range of individual outcomes, which is why a prescriber looks at the whole picture rather than the graph alone.

It is also worth noting that the trial ran alongside reduced-calorie diet and increased physical activity, not instead of them. The graph reflects a combined effort, not the medicine in isolation. For a fuller picture of how semaglutide works and what drives that curve, our semaglutide overview goes through the mechanism in plain language.

How does the 7.2mg Wegovy curve compare with the original 2.4mg results?

Since the original STEP 1 data, the Wegovy story has moved on. The MHRA approved a 7.2mg maintenance dose on 12 January 2026, and then on 14 April 2026 approved a dedicated single-dose 7.2mg pen for adults with a BMI of 30 or above. Trials at this higher dose reported around 20.7% average weight loss over 72 weeks, a meaningfully steeper curve than the 2.4mg results, and closer to the results seen with tirzepatide at its highest dose.

That convergence matters if you are trying to compare products. The 2.4mg curve and the 7.2mg curve are not the same line. Anyone looking at older Wegovy graphs is looking at data that no longer represents the full picture of what the medicine can do under the updated prescribing schedule. More on Wegovy's results (including what the 7.2mg approval changed) is covered in detail on the treatment results page.

The titration schedule still starts at 0.25mg and progresses through several steps before reaching 7.2mg. No one arrives at the top of the curve on day one. The body needs time to adjust, and each dose step is there for a reason. A prescriber reviews whether moving to the next dose is appropriate for you personally, it is not automatic.

Whether a specific pen format is available is confirmed at consultation, since supply can vary. You can read more about Wegovy weight management and what the current options look like in practice.

What do the graphs not show, and why does that matter before starting treatment?

A clinical trial graph is an average of a defined population at a defined dose with defined support. It does not show what happens after the trial ends, which is one of the more important questions.

Studies suggest that a significant proportion of weight is regained when semaglutide is stopped, particularly without ongoing lifestyle support. This is not unique to Wegovy (it reflects the underlying biology of weight regulation) but it does mean the graph of the trial period is only part of the story. Long-term maintenance is a clinical conversation, not something a graph resolves.

The graph also does not capture side effects. The majority of participants in STEP 1 experienced at least some gastrointestinal effects (nausea most commonly) particularly in the early weeks and after each dose increase. These generally eased over time, but they are real and worth knowing about before starting. Our page on semaglutide for weight loss covers the side-effect profile in more detail alongside the results data.

Equally, the STEP 1 population excluded people with type 2 diabetes, so the 15% average figure does not apply to that group; separate trial data exists for them. Eligibility for Wegovy under a private prescription broadly requires a BMI of 30 or above, or 27 or above alongside a relevant health condition such as high blood pressure or high cholesterol. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance. None of that is visible in the graph, but all of it shapes whether treatment is right for you.

If you are weighing up costs alongside expected results, the Wegovy cost page breaks down what private treatment typically involves. And if you are comparing Wegovy with tirzepatide (Mounjaro), this overview of Wegovy as a weight-loss medicine sets the two treatments side by side with the relevant trial data. The Wegovy treatment page covers eligibility, the titration schedule and how to get started through a clinical assessment.

One thing our prescribers hear fairly often: people come to a consultation having studied the graph and already decided on the outcome they want. The graph is a useful starting point (genuinely) but the conversation that follows it is where the real picture forms. If you would like to talk through what the trial data means for your situation, speak to our prescribers through a free consultation, reviewed the same day by a GPhC-registered Independent Prescriber.