Losing Weight on Wegovy: What to Expect, Week by Week

The myth: Wegovy works the same way for everyone

The most persistent misconception about losing weight with Wegovy is that results are uniform. They are not. The STEP 1 trial was conducted over 68 weeks, and even within that cohort (adults with obesity or overweight plus a weight-related condition, none with type 2 diabetes) the range of outcomes was wide. Some participants lost more than 20% of their starting weight; others lost considerably less. Biological variation, how closely participants followed dietary advice, and how long they stayed on treatment all played a role.

If you want to understand how semaglutide works specifically in the context of losing weight, it activates GLP-1 receptors involved in appetite regulation and gastric emptying, makes food feel satisfying sooner, and slows the rate at which the stomach empties. That mechanism is consistent. What varies is how strongly any given person's appetite responds to it, and how well they tolerate the escalating doses. The semaglutide overview on this site covers the pharmacology in more depth if you want the full picture.

The practical upshot: the 15% average figure from the trial is the best evidence we have, but your prescriber cannot tell you in advance whether you will land above or below it. What they can do is monitor your progress and adjust the plan if things are not moving after six months on the maintenance dose, which is exactly what NICE recommends.

What actually happens in the first weeks of Wegovy treatment

The starting dose is 0.25mg, and it stays there for roughly four weeks. At that level many people notice little in the way of appetite change, and some notice almost no weight loss at all. That is not a sign the medicine is not working, the low starting dose exists to reduce the risk of nausea and vomiting, not to produce rapid results. Expecting the scales to move dramatically in week one sets people up for unnecessary disappointment.

Doses escalate through 0.5mg, 1.0mg and 1.7mg before reaching the 2.4mg maintenance dose, typically at roughly four-weekly intervals under your prescriber's guidance. Most people begin to notice a meaningful reduction in appetite and some weight movement somewhere in the 0.5–1.0mg phase, usually around weeks five to twelve. The fuller breakdown of timing sets out how this typically progresses by dose stage.

Common side effects (nausea, loose stools, constipation, indigestion) are most noticeable in the days after each dose increase and tend to settle within one to two weeks for most people. Keeping the pen in the fridge door as a reminder to rotate injection sites each week is a small routine detail that helps consistency. If side effects feel unmanageable, the right step is to speak with your prescriber, not to skip doses independently.

How much weight can you realistically lose on Wegovy?

The STEP 1 trial result of approximately 15% average body-weight reduction at 68 weeks with the 2.4mg dose is the canonical figure, cited directly by NICE in their appraisal of semaglutide (TA875). For context, a person starting at 100kg could expect an average loss of around 15kg over that period, though actual outcomes ranged well above and below that in the study population.

A newer, higher-dose option (the 7.2mg Wegovy pen, approved by the MHRA in April 2026) produced average losses of around 20.7% over 72 weeks in trials, narrowing the gap with tirzepatide. Whether that dose is appropriate depends on clinical assessment; availability is confirmed at consultation. For a broader comparison of what the licensed injectable options produce on average, the weight-loss treatment overview sets out the evidence side by side.

The honest answer to "how much weight will I lose" is: between nothing and more than 20%, with the centre of gravity around 15% at standard maintenance dose over roughly 15–16 months. Dietary habits, activity, sleep and the presence of other health conditions all influence where you land. A prescriber assessing your full history will give you a more grounded individual expectation than any population average can.

What happens to weight loss over time, and after stopping

Weight loss on Wegovy is not linear. The rate tends to be fastest in the first six months and slows as the body reaches a new equilibrium. Plateau phases are common and do not necessarily indicate that the medicine has stopped working, they may reflect a natural settling point before the next phase of loss, or a need to revisit diet and activity patterns alongside treatment.

NICE guidance specifies that if weight loss is below 5% after six months at the maintenance dose, continuing treatment should be reviewed. That threshold is a clinical checkpoint, not a ceiling, it simply means that ongoing prescription is not automatic and requires active assessment.

Stopping Wegovy is a separate question that comes up often. The evidence is clear that a significant proportion of weight lost on semaglutide returns after discontinuation, because the medicine's appetite-suppressing effect is not permanent once it leaves your system. The post-treatment weight picture and the question of plateaus during treatment are both worth reading before making any decisions about stopping. Your prescriber is the right person to discuss an exit plan with, not something to work out alone.

For people exploring practical strategies to get the most from treatment, the practical tips page covers diet, activity and dose-stage habits grounded in the evidence. If you would like to find out whether Wegovy could be suitable for you via a same-day clinical review, start your free consultation with our prescribers.