How Does Wegovy Work? How It Helps, How Long It Takes and Typical Results (November 2026)

01 · Is it for you

Who Wegovy is for

Wegovy is licensed for weight management in adults with a BMI of 30 or above, or 27 to under 30 with at least one weight-related condition, alongside a reduced-calorie diet and more physical activity.¹ Our eligibility guide explains the criteria.

02 · Support

Getting started

Wegovy (semaglutide) is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber. Individual results vary. This page is information, not a substitute for medical advice.

03 · How it works

How Wegovy works

Semaglutide copies the action of GLP-1, a hormone released after eating. It acts on the GLP-1 receptor to reduce appetite and slow stomach emptying.¹ In practice, many people find they get full sooner, think about food less and find it easier to stick to smaller portions. It is a once-weekly injection, given on the same day each week.

04 · How long it takes

How long does Wegovy take to work?

The dose steps up after 4 weeks on each of 0.25mg, 0.5mg, 1mg and 1.7mg, so the 2.4mg maintenance dose starts from week 17.¹ Some people notice less appetite in the first weeks; for others the change is clearer at higher doses. Weight loss usually builds gradually over months rather than weeks, and the trial results below were measured after more than a year of treatment.

05 · Results

Wegovy results in trials

In STEP 1, adults on semaglutide 2.4mg lost on average 14.9% of body weight over 68 weeks, compared with 2.4% on placebo.² In the head-to-head SURMOUNT-5 trial, tirzepatide gave 20.2% average weight loss over 72 weeks versus 13.7% for semaglutide 2.4mg.³ Averages hide a wide range: some people lose more, some less. Our Mounjaro vs Wegovy page compares the two.

06 · Not losing weight

Why you might not be losing weight on Wegovy

• The dose is still low. The first months are about stepping up; the maintenance dose starts from week 17.
• Eating has crept back up. Liquid calories and snacks add up even when appetite is lower.
• A normal plateau. Weight loss rarely happens in a straight line.
• Missed doses. Gaps in treatment can slow progress.

If progress has stalled for several weeks, talk to the prescribing team. They can review your dose, side effects and plan.

07 · Getting the most from it

Getting the most from Wegovy

Medicines work best alongside changes to eating, activity and sleep. Build meals around protein and vegetables, keep active, and drink enough fluid. It is best not to drink alcohol, because it can increase side effects such as nausea.⁴ Weight tends to return after stopping, so any decision to reduce or stop should be made with the prescribing team.

08 · Pill or injection

Wegovy pill or injection

Wegovy also comes as a daily tablet containing the same medicine. In OASIS 4, adults taking semaglutide 25mg tablets for 64 weeks lost on average 13.6% of their body weight, compared with 2.2% on placebo.⁵ See our Wegovy pill vs injection guide.