All About Wegovy: the UK's Weekly Weight-Loss Injection Explained

You've heard the name everywhere, here's what Wegovy actually does inside your body

Picture this: you finish a modest meal and, for the first time in years, you genuinely don't want more. That's the hormone GLP-1 at work, and semaglutide (the active ingredient in Wegovy) is designed to replicate it. Once injected, semaglutide binds to GLP-1 receptors in the brain and gut, sending a sustained signal of fullness, slowing gastric emptying, and reducing the drive to eat. The result isn't willpower. It's biology.

Wegovy is made by Novo Nordisk and delivered via a pre-filled pen, injected under the skin once a week. The standard maintenance dose is 2.4 mg, reached by stepping up through 0.25 mg, 0.5 mg, 1 mg and 1.7 mg, each held for roughly a month to let your system adjust. In January 2026, the MHRA also approved a 7.2 mg dose, and in April 2026 a dedicated single-dose 7.2 mg pen followed. The NHS semaglutide medicines page explains what the medicine does and what to expect in plain language. The titration schedule is always managed by your prescriber, not self-selected.

It's worth knowing that Ozempic also contains semaglutide, but it is licensed for type 2 diabetes. Wegovy and Ozempic are not interchangeable for weight management purposes, even though the ingredient is the same. If weight loss is the goal, Wegovy is the licensed product.

What the trial results actually mean for someone thinking about starting

The STEP 1 trial is the main evidence base most clinicians refer to. It followed adults with obesity over 68 weeks and found an average body-weight reduction of around 15% at the 2.4 mg maintenance dose, alongside a reduced-calorie diet and increased physical activity. That's a meaningful number, for someone weighing 100 kg, it translates to roughly 15 kg. The trial was published in the New England Journal of Medicine, and NICE reviewed its findings before recommending semaglutide for use in appropriate patients.

The newer 7.2 mg dose reported around 20.7% average weight loss over 72 weeks, narrowing the gap with tirzepatide. If you want to dig into what Wegovy's results look like in more detail, including how results compare across the dose range, that page goes further. One thing all the trials share: results are built on lifestyle changes alongside the medicine, not instead of them. The injection changes appetite; what you eat and how you move still matters.

It's also honest to say that results vary. Some people lose considerably more than the trial average; others less. A prescriber won't promise a specific figure, and neither will we.

Who the UK licence actually covers, and what the NHS route looks like compared to private

The licensed criteria for Wegovy are: adults aged 18 or over, BMI of 30 or higher, or BMI of 27 to 29.9 with at least one weight-related condition such as high blood pressure, high cholesterol, type 2 diabetes or obstructive sleep apnoea. Lower BMI thresholds apply for some ethnic backgrounds under UK clinical guidance. Meeting those numbers doesn't automatically mean Wegovy is right for you, a prescriber weighs up your full medical history, any contraindications, and current medications before deciding.

On the NHS, access to Wegovy is more restricted. NICE's recommendation (TA875) limits it to a maximum of two years, within a specialist weight management service, for adults with at least one weight-related comorbidity and a BMI of 35 or above (or lower thresholds for some ethnic backgrounds). Waiting lists through those services are often long. Private routes, through a GPhC-registered online pharmacy, offer a legal alternative for people who meet the licensed criteria but don't qualify for NHS Wegovy or don't want to wait. You can think through whether Wegovy could be right for your situation before committing to anything. If you're also curious how the cost side of private treatment works, this breakdown of Wegovy pricing in the UK covers what's typically included and what to watch out for.

One practical note: if your order falls around a bank holiday or you're planning ahead for a holiday away, it's worth placing it with enough lead time, treatment dispatched before 12pm on a working day arrives the next working day, but bank holidays shift that window.

Side effects, safety signals and when to get medical help

The most commonly reported side effects are gastrointestinal: nausea, vomiting, diarrhoea, constipation, indigestion and burping. These tend to be most noticeable when starting or moving to a higher dose, and for many people they settle over a few days to two weeks. Fatigue, headache and dizziness also appear in the data. Injection-site reactions are possible but generally mild.

There are rarer but more serious signals to know about. Acute pancreatitis is a known infrequent risk with GLP-1 medicines. Seek urgent medical help for severe, persistent abdominal pain that spreads to the back, with or without vomiting, don't wait to see if it passes. Gallbladder problems and symptoms of a serious allergic reaction (difficulty breathing, swelling, rapid heartbeat) also warrant immediate attention. The MHRA's Yellow Card scheme lets patients and clinicians report suspected side effects directly to the regulator, and it applies to Wegovy as to any medicine.

Wegovy is not recommended during pregnancy, while breastfeeding, or when actively trying to conceive. It is not licensed for under-18s. Women using oral contraceptives should discuss their options with a prescriber, GLP-1 medicines can affect how quickly the gut absorbs other medicines, which is relevant for the pill. If you're heading into a surgical procedure, tell the anaesthetist and your surgical team that you're taking semaglutide. More verified facts about Wegovy cover these safety points in fuller detail. Our clinical team reviews every consultation personally before any prescription is issued, which means questions like these get answered before treatment begins, not after.

If you'd like to find out more about how Wegovy works and what to expect before making any decisions, that's a good place to start. If you'd also like to read what other people using Wegovy have said about their experience, those accounts can give you a clearer sense of what treatment is like in practice. If you'd like to check whether you meet the criteria and have your situation reviewed by a prescriber, check your eligibility with our free consultation.