Semaglutide: how long treatment takes, and what to expect along the way

The first weeks: why things feel quiet before they build

Starting semaglutide at 0.25mg is a deliberate, calibrated approach. The opening dose is there to let your body adjust to the medicine, not to produce dramatic results, so if the first four weeks pass without obvious change on the scales, that is expected rather than a sign that something is wrong. Most people move through 0.5mg, 1.0mg and 1.7mg before reaching the standard 2.4mg maintenance dose, with roughly four weeks at each level. That progression alone takes around sixteen weeks.

During this period the most noticeable effects are often gastrointestinal: nausea, changes in appetite, and occasionally looser stools or constipation, which tend to ease as the body adapts. A quick habit that helps is weighing yourself on the same day each week, first thing in the morning, so you're comparing like with like rather than reacting to daily fluctuation. Small, consistent losses that seem unremarkable week to week can add up to something significant over a few months. The fuller picture of when semaglutide starts working gives more detail on what the early phase typically looks like.

Months two to six: where most of the weight reduction happens

Once someone reaches and stabilises on their maintenance dose, the rate of weight loss tends to be at its most consistent. The STEP 1 clinical trial, published in the New England Journal of Medicine, followed 1,961 adults over 68 weeks. Participants on 2.4mg semaglutide lost an average of around 15% of body weight across the study, a figure that accumulated progressively, with losses continuing into the later months of the trial rather than plateauing early.

This matters for how you read your own progress. A loss of 1–2% of body weight per month on maintenance is broadly consistent with what the trial showed. If that pace feels slower than expected, it is worth knowing that the curve tends to flatten naturally over time as the body adjusts, which is clinically normal rather than a sign the medicine has stopped working. The timeline for losing weight on semaglutide explores the evidence behind these phases in more depth.

How long you stay on it: a clinical decision, not a calendar entry

This is the question people find hardest to get a straight answer on. NICE's recommendation for NHS use of semaglutide (Wegovy) specifies a maximum of two years within a specialist weight management service, with treatment reviewed if less than 5% weight loss has occurred after six months on the maintenance dose. That two-year limit applies to the NHS pathway specifically.

Private treatment through a regulated pharmacy is reviewed differently: at every repeat, a prescriber assesses whether continuing remains clinically appropriate, rather than applying an automatic cut-off. Duration therefore reflects your response, your health profile and your prescriber's clinical judgement. For most people, weight does return after stopping, which is why the question of how long you can stay on semaglutide and what the guidance actually says about long-term use are worth understanding before you start. The Wegovy treatment overview sets out the licensed indication and what private prescribing involves.

Making the decision: what a prescriber actually weighs up

Deciding whether to start, continue or adjust semaglutide treatment involves more than a BMI figure and a calendar. A prescriber looks at your rate of response, any side effects you're experiencing, other medicines you take (oral contraceptives, for instance, may have reduced absorption during the titration phase, worth raising at your review), your weight-related health conditions, and your own goals. The decision to stop is also clinical: an abrupt end without a plan for maintaining progress is rarely the right call.

If cost is part of the picture for you (and it often is) how Wegovy is priced privately explains what a transparent fee typically includes, and why the lowest advertised figure is rarely the complete story. Semaglutide is a prescription-only medicine; the only legal route to it is through a regulated clinical service. At nume, every repeat order is reviewed by a GPhC-registered prescriber before anything is dispensed. If you'd like to understand whether treatment fits your situation, the place to start is a free consultation with our clinical team.

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