What are the long-term effects of Wegovy on your body and health?

What 68 weeks of trial data actually showed

The STEP 1 trial, published in the New England Journal of Medicine, is still the anchor reference for semaglutide's long-term effects on weight. Over 68 weeks, adults with obesity taking semaglutide 2.4 mg lost an average of around 15% of their body weight, against roughly 2.4% in the placebo group. That gap is clinically meaningful — not just cosmetically. Alongside weight, participants saw reductions in waist circumference, blood pressure, fasting blood sugar and LDL cholesterol. These aren't trivial numbers; they sit in territory where cardiovascular risk and metabolic health start to shift.

If you want to understand what the long-term effects of Wegovy look like beyond the trial headlines, the cardiovascular benefit is one of the most significant findings, going beyond the numbers on a clinic scale. A separate approved indication for Wegovy covers reduction of major cardiovascular event risk in eligible adults, a signal that semaglutide's mechanisms reach further than appetite alone. What Wegovy actually does in the body covers the GLP-1 receptor pathway in more detail if you want the mechanism behind the numbers.

One pattern the trial data makes plain: most of the weight lost during active treatment returns if the medicine is stopped. A STEP 4 withdrawal sub-study confirmed that participants who discontinued regained a large proportion of lost weight within a year. This isn't a failure of the medicine; it reflects how the underlying biology works. It does, though, make the question of how long people stay on Wegovy a genuinely important clinical conversation rather than an afterthought.

Safety over time: what the regulators watch

The NHS medicine page for semaglutide lists the most commonly reported side effects as gastrointestinal: nausea, vomiting, constipation, diarrhoea and indigestion, especially in the early weeks or after a dose increase. For most people, these settle. Longer-term, the safety picture is shaped by two things: the MHRA's ongoing post-marketing surveillance under the Black Triangle scheme, and specific safety updates as new signals emerge.

In January 2026 the MHRA issued a Drug Safety Update highlighting acute pancreatitis as an infrequent but serious risk with GLP-1 medicines. Severe, persistent stomach pain that radiates to the back (with or without vomiting) requires urgent medical attention. This isn't a reason to avoid treatment for everyone, but it is a reason to know the warning sign. A simple checking habit worth building: once a month, take a moment to read through any updated patient information leaflet sent with your pen, since wording and warnings do occasionally change as post-marketing data accumulates.

Gallbladder problems are also listed as a known long-term risk with sustained weight loss and semaglutide use specifically. Rapid weight loss of any kind increases the chance of gallstones. Prescribers factor this into the clinical picture, which is one reason repeat prescriptions at nume involve a clinical re-review rather than automatic renewal. You can explore the broader safety context through guidance on long-term Wegovy use.

Does Wegovy keep working over time?

The honest answer is: it depends on the dose reached, individual response, and what's going on alongside the medicine. The 2.4 mg weekly dose produced its largest average weight losses from around weeks 16–20 onward in most trials, with a plateau rather than further steady decline thereafter. The newly approved 7.2 mg single-dose pen (cleared by the MHRA in April 2026) showed around 20.7% average weight loss over 72 weeks in trial data, narrowing the gap with tirzepatide at its highest doses. Whether that higher dose is appropriate is a prescriber decision, not a patient choice to make alone.

On whether Wegovy works long term, the evidence is fairly consistent: sustained use produces sustained effect; stopping produces rebound. For people wondering whether they are candidates for longer-term treatment, the question of how durable Wegovy's effects are sits at the heart of the prescriber conversation, not just the starting one. NICE's recommendation for semaglutide (TA875) notes a maximum recommended duration of two years within a specialist weight management service on the NHS, a framing that reflects both the evidence base and the current commissioning structure, rather than a ceiling on what the medicine can do biologically. Private prescribing follows the licensed SmPC, assessed individually.

If you'd like to read Wegovy testimonials from people who have used it over time, that can offer a useful perspective alongside the clinical data. And if questions remain about what's right for your situation, our clinical team reviews every consultation personally.