Reading the Wegovy Chart: What the Evidence Actually Shows

What the STEP 1 trial chart tells us — and what it leaves out

The STEP 1 trial, published in the New England Journal of Medicine, is the anchor study behind Wegovy's licence. Over 68 weeks, adults with obesity who received semaglutide 2.4 mg alongside lifestyle support lost an average of roughly 15% of their body weight, compared with around 2.4% in the placebo group. That headline figure is the one most people see first when they look at a Wegovy results chart.

What the chart rarely shows is the shape of the loss. Weight reduction in the trial was not linear. The steepest relative drop tends to occur in the first 20 weeks, when appetite suppression is most pronounced and the body is adapting to the medicine. Progress slows as the dose stabilises and the body settles at a new set point. Some participants reached a plateau before week 68; others continued losing weight more gradually. Knowing this shape matters because many people interpret a plateau as failure, when it is actually the normal trajectory the trial evidence predicts.

A question our prescribers hear most weeks is whether stopping the medicine once weight loss slows is the right call. The trial data suggest the opposite: participants who discontinued semaglutide regained most of the weight within a year, which is why ongoing clinical review (not just an initial chart) is central to how treatment is managed.

The full dose escalation chart: from 0.25 mg to 7.2 mg

The standard Wegovy escalation runs across five steps. Treatment opens at 0.25 mg once weekly for four weeks, a tolerability level rather than a therapeutic one: its job is to let the body adjust to the medicine rather than to produce weight loss. From there the dose moves to 0.5 mg, then 1.0 mg, then 1.7 mg, with each step lasting approximately four weeks. The 2.4 mg maintenance dose begins around week 16 for most people, though your prescriber may keep you at an intermediate step longer if gastrointestinal side effects are significant.

In January 2026 the MHRA approved a 7.2 mg maintenance dose, and on 14 April 2026 a dedicated single-dose 7.2 mg pen was authorised, becoming the first of its kind. This higher-dose option is licensed for adults with a BMI of 30 or above; starting dose remains 0.25 mg and the same gradual titration applies. Trials at this level reported around 20.7% average weight loss over 72 weeks, bringing results closer to those seen with tirzepatide 15 mg. If you want to understand how the full titration sequence works in practice, that page covers each step in detail.

For anyone already established on the 2.4 mg injection, the move to 7.2 mg is a clinical decision, availability and suitability are confirmed at prescription review, not assumed from the chart. You can explore the broader pen and dose sizes to understand the physical format at each level.

Who the chart applies to, and where eligibility draws the line

The Wegovy dosing schedule only applies once a prescriber has confirmed the medicine is appropriate for you. The licensed eligibility threshold is a BMI of 30 or above, or a BMI from 27 upwards if at least one weight-related condition is present, such as high blood pressure, raised cholesterol, or obstructive sleep apnoea. Lower BMI thresholds of 2.5 kg/m² apply for some ethnic backgrounds under UK guidance. BMI alone does not determine suitability; your full medical history, current medicines and any contraindications are part of the clinical picture.

Wegovy is not recommended during pregnancy, while breastfeeding, or if you are trying to conceive. It is not licensed for people under 18. Anyone with a history of pancreatitis or certain gastrointestinal conditions would need a careful prescriber discussion before starting. On the Wegovy overview page there is a fuller summary of who the medicine is and is not suitable for, which is worth reading alongside the dose chart.

The NICE technology appraisal for semaglutide (TA875) sets out the NHS criteria, which are stricter than the licensed eligibility, specifically requiring access through a specialist weight management service and capping treatment at a maximum of two years. Private treatment through a regulated pharmacy operates under the licensed eligibility criteria rather than the NHS commissioning thresholds, though a prescriber still applies clinical judgement at every step. You can compare semaglutide's evidence base and understand what that distinction means in practice.

Putting the chart in context: cost, access, and the private route

The dose chart is only useful once you have a legitimate supply. Wegovy is a prescription-only medicine; no online seller may legally supply it without a valid prescription following a clinical assessment. The MHRA has warned repeatedly about counterfeit weight-loss pens sold without a prescription, fake pens have in some cases contained insulin, with serious consequences for buyers.

For people considering private treatment, the honest picture on cost matters. Eli Lilly raised the UK list price of its tirzepatide pen from September 2025, and private prices across the market for GLP-1 medicines typically range from around £149 to £375 per month depending on dose and provider. The weight-loss treatments page sets out what is currently available through a regulated pharmacy, what clinical review involves, and how to check whether any online pharmacy is registered on the GPhC register before you order. A low headline price that excludes the prescription, clinical review and aftercare is rarely the saving it appears.

For a side-by-side view of how Wegovy's timeline and outcomes compare with tirzepatide's, the semaglutide chart comparison puts the two trial datasets next to each other. If you are tracking your own progress week by week, the Wegovy weight-loss chart breaks down what typical trajectories look like at each phase of treatment. Check your eligibility with our prescribers if you are ready to take the next step.