How long does Wegovy take to work — and what should you expect?

The decision most people get wrong: judging progress before the dose is therapeutic

The titration schedule exists for your comfort, not for weight loss. Starting at 0.25mg, the first four weeks are about letting your body adjust to the medication, nausea, if it comes, is usually most noticeable here, and the appetite reduction is mild at best. Expecting dramatic results in week one sets up a comparison that the medicine isn't designed to meet yet.

Once the dose climbs past 1.0mg, most people report a noticeable shift: foods they previously craved feel less compelling, portions feel more satisfying sooner, and habitual eating starts to feel like a choice rather than a compulsion. That shift is your first real signal that the medicine is doing its job. If you're tracking the full Wegovy treatment picture, this mid-titration point is the earliest meaningful marker to note.

The practical upshot: give yourself at least twelve weeks before drawing conclusions. That's not arbitrary patience, it's the minimum time needed to reach and settle into a therapeutic dose. Stopping at week six because the scales haven't moved much isn't giving the treatment a fair trial. A prescriber will tell you the same thing, and it's worth asking them directly at your first review.

One thing worth factoring in: if your schedule involves being away from home or managing injections around a busy working day, it helps to read up on taking Wegovy to work, since storage and timing considerations are easy to plan around once you know what to expect. Building a consistent weekly injection day into a normal week (rather than trying to start mid-holiday) makes the early routine easier to keep.

What the evidence actually shows across the first year

The STEP 1 trial followed adults with obesity for 68 weeks. At 2.4mg maintenance dose, average weight loss reached approximately 15% of starting body weight, a figure the NHS semaglutide guidance reflects in its patient-level information. But that headline figure obscures the shape of the curve: weight loss was fastest between roughly weeks 12 and 40, then slowed as participants approached a new metabolic steady state.

This deceleration in the second half of treatment is normal and does not mean the medicine has stopped working. It means your body has reached a lower set point and is defending it. People who continue treatment maintain that lower weight; data from extension periods suggest that stopping the medicine is associated with regain, which is why the question of whether Wegovy's weight loss is permanent is one our prescribers discuss with every patient before treatment begins.

The higher 7.2mg maintenance dose, approved by the MHRA in early 2026, produced around 20.7% average weight loss over 72 weeks in its pivotal trial, approaching the results seen with tirzepatide at its highest dose. Whether that option is suitable depends on how you've responded to 2.4mg; it isn't a first step, and specific dose availability is confirmed through the clinical consultation rather than assumed upfront.

For a broader look at how semaglutide's timeline compares across treatment forms, the semaglutide time-to-work overview covers the evidence across injection and tablet presentations.

Side effects across the timeline, and what they tell you about progress

Gastrointestinal effects (nausea, loose stools, indigestion, burping) follow a predictable pattern: they tend to peak in the first few weeks after each dose step-up and settle within days to two weeks as your body adjusts. This means the transition from 1.7mg to 2.4mg can feel like restarting the early experience, briefly. It usually passes.

If nausea is significant but weight loss is also building, that's not a reason to stop, it's the expected biology of a medicine that slows gastric emptying. Eating smaller meals, staying hydrated and avoiding high-fat foods at the worst moments helps most people through it. Your prescriber can advise if symptoms feel unmanageable.

The side effect that warrants urgent attention at any point is severe, persistent stomach pain that radiates towards the back, with or without vomiting. This can be a sign of pancreatitis, which, whilst uncommon, is a recognised risk with GLP-1 medicines and was the subject of an MHRA Drug Safety Update in January 2026. Get medical help promptly if this happens, don't wait for your next scheduled review. Any suspected side effects can also be reported at the MHRA's Yellow Card scheme.

For a more detailed look at what the first weeks feel like in practice, the guide to when Wegovy starts working walks through the early experience week by week.

The decision: when to reassess, and with whom

NICE's guidance on semaglutide (TA875) suggests that if less than 5% weight loss has occurred after six months at maintenance dose, continuing the treatment should be reviewed. That review belongs with your prescriber, not with a personal judgment call made alone. Six months at maintenance is a long runway, it's not a prompt to reassess at week ten.

The cost of treatment is a real factor in how people think about this timeline, and it's worth exploring what a full treatment programme includes before committing. At nume, every repeat order goes through a fresh clinical review, no automatic renewals. That structure exists partly because the right moment to adjust, continue or stop is a clinical decision, not an administrative one.

If you're still in the early stages and wondering whether your response is on track, the full explainer on whether Wegovy takes time to work goes into more depth on what a normal response looks like versus what merits a conversation with your prescriber. Our clinical team are also reachable through the FAQs for general questions while you're getting started.