How long after your first Wegovy injection does it start working?

Step 1: The first two weeks, your body is adjusting, not yet losing

The honest answer many people wish they'd heard earlier: the starting dose of 0.25 mg is a tolerability dose. Its purpose is to introduce semaglutide to your system without overwhelming it, not to produce rapid weight loss. So if the scales barely shift in the first fortnight, that is expected and normal.

What you may notice instead is a subtle shift in how hunger feels. Some people describe eating half a plate and feeling done, or finding they've forgotten to snack. That change in appetite signalling is the medicine beginning to act on the GLP-1 receptors in the brain and gut. Nausea, mild bloating or looser stools are common companions in these early days, a sign the medicine is biologically active, not a sign something is wrong. The first-week symptoms of Wegovy tend to settle within about two weeks for most people.

Stick with the low-calorie diet and activity your prescriber recommended. These weeks are about building the foundation, even if the mirror isn't showing it yet.

Step 2: Weeks 4–12, dose increases and measurable change

After four weeks on 0.25 mg, your prescriber will typically move you to 0.5 mg, then onward through 1.0 mg and 1.7 mg on roughly monthly steps. Each increase may briefly revive the GI side effects you had at the start, that pattern is normal and usually short-lived.

This is the phase when most people see the scales begin to move. The appetite-suppressing effect strengthens at higher doses, and with a sustained calorie deficit, weight loss becomes measurable. A loss of 2–4% of body weight over the first 12 weeks is common; some people lose more, some less. Neither means treatment has failed, individual responses to semaglutide vary, and how long Wegovy takes to work can differ quite widely between people of similar weight and dose. If you want a closer look at the early signs to watch for, our guide on how fast Wegovy starts working walks through what typically happens at each stage of the titration.

If you are curious how the titration schedule compares between Wegovy and other licensed options, the weight-loss treatment overview sets that out clearly.

Step 3: Months 3–6 and beyond, the maintenance phase is where the evidence sits

The largest body of evidence for Wegovy comes from the STEP programme, particularly STEP 1, published in the New England Journal of Medicine, which followed adults on 2.4 mg semaglutide for 68 weeks. Average weight loss at that point was around 15% of starting body weight. That number accumulated slowly and steadily, not in a rush during month one.

Reaching 2.4 mg typically takes about 16 weeks of titration. From there, the maintenance dose does the sustained work. Many people find the strongest weight-loss period runs roughly from months 3 to 9, with a gradual plateau after that as the body reaches a new equilibrium. That plateau is not the medicine stopping; it reflects normal physiology. For a more detailed breakdown of the typical timeline, our page on how long it will take for Wegovy to start working covers what to expect month by month.

If fewer than 5% of body weight has been lost after six months on the maintenance dose, NICE guidance suggests reviewing whether to continue, your prescriber will discuss this with you. The NICE appraisal of semaglutide (TA875) sets out the full clinical framework for when treatment is considered effective. For a fuller picture of what the evidence shows, the Wegovy treatment page covers the trial data alongside the practical details of how it is used in the UK.

If you are at that point in your journey and wondering what comes next, or you haven't started yet and want a prescriber's view on whether Wegovy is right for you, reading some Wegovy stories from people who have been through the process can help you understand what a realistic journey looks like before you decide. You can also check your eligibility with our clinical team, a GPhC-registered Independent Prescriber reviews every consultation, on the same day it is submitted.