Reading the Wegovy weight-loss graph: what the trial data shows

Why the graph drops fastest in the first few months

Open the STEP 1 trial chart and the first thing you notice is a steep early descent. Semaglutide works by activating GLP-1 receptors involved in appetite signalling and gastric emptying, so when the dose climbs through the titration schedule the effect on hunger becomes increasingly pronounced. That is why the curve steepens as each dose step lands, not from the very first injection. The starter dose is not where the weight-loss work happens, it exists to let your system adjust, which is why the graph barely moves in weeks one to four.

By around week 20 the curve's gradient softens but does not flatten. Weight continues to fall; the pace simply changes. This matters if you are comparing a 12-week progress photo against the full 68-week chart, and you can see exactly how those stages look on our Wegovy weight loss graph. You can read how the titration schedule itself is structured on our Wegovy treatment overview.

The NHS patient information for semaglutide notes that treatment decisions, including dose changes, are made by your prescriber, the graph is evidence for why patience through the schedule tends to pay off.

What the plateau phase in the data tells you about long-term use

Around weeks 52 to 68 most participants' curves level. This is not treatment failure; it is the expected biology. The body reaches a new equilibrium at a lower weight setpoint, and appetite-suppressing signals stabilise. NICE's appraisal of semaglutide for weight management, TA875, references this plateau when setting out the six-month review criteria: if less than 5% weight loss has occurred by the time a patient reaches the maintenance dose, continuing treatment is reconsidered.

One practical implication: the graph shape argues against switching or stopping during the steep descent phase on the basis of impatience, and equally argues against assuming a plateau means something has gone wrong. A prescriber reviewing your progress at each repeat order is in a far better position to interpret your personal curve than the population average alone. That clinical re-review happens before every repeat at our pharmacy, it is not automated.

For readers weighing up which injectable treatment fits their situation, a comparison of the semaglutide evidence base alongside the tirzepatide data may be useful context before a consultation.

How Wegovy 7.2 mg shifts the picture

The 2.4 mg curve from STEP 1 is not the end of the graph story. On 14 April 2026 the MHRA approved a dedicated single-dose 7.2 mg Wegovy pen (one weekly injection, a built-in covered needle that locks after use) for adults with a BMI of 30 or above, and our Wegovy 1 page covers the full pen format and dosing details for anyone starting out. Trial data for this higher dose reported an average weight reduction of around 20.7% over 72 weeks, which begins to narrow the gap with tirzepatide 15 mg results seen in the SURMOUNT-5 head-to-head trial.

What this means for the graph: the 7.2 mg curve descends further before reaching its plateau, though the titration path to get there still starts at 0.25 mg. Rushing to the maximum dose does not speed the graph up; the steps exist for tolerability. Specific dose and pen-format availability is confirmed at consultation rather than assumed.

If cost is part of the decision alongside results, our Wegovy cost guide explains what is and is not included in private treatment pricing in the UK. And anyone curious whether a common food interaction could affect the curve can find the evidence on our grapefruit and Wegovy page.

What the graph does not show, and why the clinical picture matters

Population averages hide the range. Some participants in STEP 1 lost more than 20% of their body weight; others lost closer to 5%. Baseline BMI, adherence to lifestyle changes, whether nausea led to early dose pauses, and individual metabolic variation all contribute. The graph is an average, not a forecast.

Side effects can also shape a personal curve in ways the trial mean does not capture. Gastrointestinal symptoms (nausea, loose stools, indigestion) are the most common, particularly at dose increases, and they can temporarily reduce food intake beyond the medicine's direct appetite effect. They usually settle within one to two weeks. Any severe, persistent abdominal pain that extends toward the back warrants prompt medical attention, as the MHRA has highlighted in relation to pancreatitis risk with GLP-1 medicines.

The broader weight-loss treatment landscape puts semaglutide in context alongside other options. If you have reviewed the data and want a prescriber to assess your suitability, our team is available through our free consultation. Consultations are read by a GPhC-registered Independent Prescriber the same day, a real clinician, not a triage algorithm. If approved, treatment is dispatched the same day for free next-working-day delivery via DPD, arriving in plain, unbranded packaging with tracking sent directly to your phone.