When did Wegovy start working — and what should you expect at each stage?

What the STEP 1 trial tells us about early versus sustained response

The STEP 1 study is the most detailed picture we have of how semaglutide 2.4 mg behaves over time. Participants lost weight progressively across 68 weeks, with steeper change in the middle phase of the trial once maintenance dosing was established, rather than in the first few weeks. That pattern matters because it sets realistic expectations: the question most people ask (when does Wegovy start working) is really two different questions. When does it start acting on appetite? And when does measurable weight change become obvious?

The appetite effect typically arrives first. Semaglutide slows gastric emptying and acts on brain receptors involved in hunger signalling, so a reduced urge to eat is often the earliest detectable sign the medicine is doing something. The scales take longer. Body weight reflects weeks of cumulative energy intake, so even with a meaningful appetite shift, the numbers change gradually. Most participants in the trial saw the most dramatic monthly rate of loss between roughly weeks eight and thirty-two, once doses were higher and the body had adapted to the medicine.

What this means practically: the absence of dramatic change in week one is not a signal that something is wrong. It is what the evidence predicts. The NHS semaglutide page sets similar expectations, noting that weight loss is a gradual process alongside lifestyle changes.

How the dose ladder shapes your personal timeline

The titration schedule (starting at 0.25 mg and increasing roughly every four weeks toward the 2.4 mg maintenance dose) directly affects when results become most pronounced. Each dose step tends to bring a fresh reduction in appetite within days, followed by a further increment of weight change over the following weeks. People sometimes interpret the plateau between steps as the medicine stopping work; it is more accurately the body settling at a new equilibrium before the next increase.

This is one reason timelines vary so much between individuals. Someone who tolerates each increase quickly and reaches 2.4 mg at the earliest opportunity will accumulate different results at, say, week twenty than someone who spends longer at intermediate doses because of GI side effects. Neither is doing it wrong. The prescriber sets the pace based on tolerability, not speed. If you want to understand when Wegovy will start working for you and what to expect at each stage, that guidance covers the typical progression in more detail. If you want to understand how quickly the dose increases typically progress, the guidance on how Wegovy's timeline relates to weight loss specifically covers this in more detail.

One simple habit worth building: weigh yourself at the same time each morning, after using the bathroom and before eating, and record it. A single day's number is noisy; a weekly trend line is much more informative. Most people find that charting even two or three weeks of daily weights makes the direction of travel unmistakeable even when any single reading looks flat.

When response is slower than expected, and what the guidance says

Some people reach the maintenance dose and find weight loss slower than the trial average. That is not unusual: STEP 1 reported an average, and individual responses spread across a wide range. Factors that influence response include starting weight, activity level, dietary patterns alongside treatment, sleep quality, and underlying metabolic conditions.

NICE's appraisal of semaglutide (TA875) includes a practical stopping criterion: if less than 5% of body weight has been lost after six months at the highest tolerated dose, continuing should be reviewed with a prescriber. That threshold exists because the medicine is not universally effective for everyone, and continuing without meaningful response carries its own considerations around side effects and cost.

If you are wondering whether your response is on track, the most useful conversation is with the prescriber who reviewed your case, not a forum. A question our prescribers hear regularly is whether a slow first month means the medicine is not working, usually, it does not. Questions about what it actually feels like when Wegovy begins to take effect are worth reading alongside this page for that early-weeks picture. You can also explore the Wegovy treatment overview for a broader view of who the medicine is licensed for and how the clinical pathway works.

Cost, access and what a supervised prescription looks like

Wegovy is a prescription-only medicine and must be assessed and prescribed by a qualified clinician before you receive it. Understanding the timeline is relevant to how Wegovy pricing works in practice, because the titration period means your first several months may be at lower doses before reaching maintenance. A service that includes ongoing clinical review at each repeat (rather than a one-off prescription) matters here, because titration decisions should be made with proper oversight.

At nume, every repeat order is reviewed by a GPhC-registered prescriber before dispatch, not auto-renewed. There are no subscriptions; each repeat is its own clinical assessment. If you have questions before starting, the FAQs cover the process, or you can reach the team directly via the contact page. For a broader look at the injectable and oral weight-loss medicines available, the weight loss treatment overview is a good place to start.

If you are clinically suitable and ready to explore whether Wegovy is right for you, start your free consultation with our prescribers today.