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Start journey Learn moreFrom trial data to your fridge door: how Wegovy works and who it's for
What the STEP trials found about semaglutide and weight
The reason Wegovy exists as a weight-management medicine at all comes down to the STEP programme, a set of large randomised trials run by Novo Nordisk. The headline result is worth quoting plainly. In STEP 1, published in the New England Journal of Medicine, adults with obesity who took semaglutide 2.4mg once a week for 68 weeks, alongside reduced-calorie eating and more activity, lost on average around 15% of their body weight. The placebo group lost far less.
Fifteen percent is a meaningful number. For someone weighing 100kg, that's roughly 15kg of average loss across the trial period, though individual results varied a lot and some people lost considerably more or less. The figure is an average from a controlled study, not a promise about what any one person will see.
What the trial also showed is that the medicine works with lifestyle change, not instead of it. Every participant was supported with dietary advice and activity guidance. You can read the NHS overview of semaglutide for a patient-level summary of what the medicine does and what to expect. If you want the wider picture of how these injections fit together, our page on weight-loss injections in the UK sets out the landscape.
One caution on the spelling: searching "wegovi" sometimes surfaces sellers offering pens that aren't the genuine article. The real medicine is Wegovy, and it only reaches you legitimately through a prescription.
The gut-hormone mechanism behind the once-weekly pen
Semaglutide is a GLP-1 receptor agonist. GLP-1 is a hormone your gut releases after eating, and it does two useful things: it tells your brain you're full, and it slows how fast your stomach empties. Wegovy mimics that hormone, so appetite tends to drop and meals feel more filling for longer. That's the plain version of the science.
It's given as a once-weekly injection under the skin, usually into the abdomen, thigh or upper arm, with the site rotated each time. The pen comes pre-filled and the schedule is built to start low and rise gradually, which is a deliberate design choice rather than a marketing quirk. The first dose isn't there to shift weight; it's there to let your body adjust before the strength climbs.
The UK maintenance pathway historically stepped through 0.25mg, 0.5mg, 1.0mg, 1.7mg up to 2.4mg, with roughly four weeks at each level. Exact timing and steps are decided by the prescriber, never self-managed. We won't tell you what to inject or when; that belongs in the consultation and the leaflet in the box.
Wegovy activates a single hormone pathway. That contrasts with tirzepatide, which works on two. If the dual-hormone approach interests you, our explainer on tirzepatide and how it differs covers the distinction without the jargon.
The higher 7.2mg dose the MHRA approved in 2026
Wegovy isn't standing still. On 14 April 2026 the MHRA approved a dedicated single-dose 7.2mg pen for adults with obesity, meaning a BMI of 30 or above. It delivers one pre-set weekly injection, has an auto-dosing mechanism with a covered needle, and locks after use. In trials, the 7.2mg dose produced average weight loss of around 20.7% over 72 weeks, which brings it close to the results seen with the strongest tirzepatide dose.
A few things to keep straight. The higher dose is licensed only for a BMI of 30 or more, not for lower BMIs and not for the cardiovascular indication. The starting dose is still 0.25mg, with the prescriber titrating upward roughly every four weeks; 7.2mg is the ceiling, not where anyone begins.
We won't claim to hold any particular dose or pen format in stock, because specific availability is something confirmed at consultation rather than promised on a web page. What matters here is that the option now exists in the UK and sits within the same prescription-only framework as every other strength. You can dig into dose-level detail on our Wegovy dosing overview.
Who Wegovy is licensed for, and where the NHS line sits
The licensed criteria are straightforward. Wegovy is for adults with a BMI of 30 or more, or a BMI of 27 or more who also have a weight-related condition such as high blood pressure, high cholesterol, prediabetes, type 2 diabetes or obstructive sleep apnoea. Lower thresholds can apply for some ethnic backgrounds under UK guidance, and BMI on its own never guarantees a prescription; the whole clinical picture matters.
NHS access is a separate question from the licence. NICE recommends semaglutide (TA875) only for up to two years, within a specialist weight management service with multidisciplinary support, for people meeting fairly strict BMI and comorbidity criteria. Waiting lists for those specialist services are commonly long, which is the reality many people run into.
That's where a regulated private route becomes relevant for people who don't meet the NHS thresholds or don't want to wait. NICE's appraisal of semaglutide (TA875) spells out the NHS conditions in full. Our broader guide to weight-loss treatment options puts the routes side by side without pretending one suits everyone.
Pregnancy, breastfeeding and trying to conceive are situations where Wegovy isn't recommended, and it isn't licensed for under-18s either. Those exclusions get discussed properly during assessment.
Side effects: what's common, what's rare, and what needs urgent help
Most people who start Wegovy notice something in the digestive department first. Nausea is the usual one, along with diarrhoea, constipation, indigestion, burping and sometimes vomiting. Tiredness, headache and mild injection-site reactions turn up too. These effects are typically most noticeable just after starting or after a dose increase, and for many people they settle within days to a couple of weeks.
The slow-titration schedule exists partly to keep those symptoms manageable, which is why the strength climbs gradually rather than jumping to the maintenance dose.
Rarer but serious risks deserve a clear mention. In January 2026 the MHRA issued a safety update flagging acute pancreatitis as an uncommon but potentially serious side effect of GLP-1 medicines. The signal to act on is severe, persistent stomach pain that may spread through to your back, with or without vomiting; that warrants urgent medical help. Other reasons to seek help include signs of a gallbladder problem, an allergic reaction, or dehydration from severe sickness. You can report any suspected side effect through the MHRA Yellow Card scheme, which also takes reports about suspect sellers. For the fuller safety picture, our general FAQs cover common questions patients raise.
Wegovy, Ozempic and Wegovy tablets: telling the semaglutides apart
This trips people up constantly, so let's be precise. Wegovy and Ozempic are both semaglutide, but they're licensed for different things. Wegovy is for weight management. Ozempic is licensed for type 2 diabetes and is not a weight-loss product, even though it contains the same active ingredient. Presenting Ozempic as a weight-loss treatment gets the licensing wrong.
Then there's the tablet. On 11 June 2026 the MHRA approved Wegovy tablets, an oral form of semaglutide, as the first oral GLP-1 medicine licensed in the UK for weight management. It's taken once daily first thing in the morning on an empty stomach with a small sip of water, then you wait at least 30 minutes before food, drink or other medicines. It stores at room temperature, which makes it easier to travel with than an injection.
In the OASIS 4 trial, the tablet produced around 13.6% average weight loss over 64 weeks, rising to roughly 17% among participants who stayed fully adherent. Don't confuse it with Rybelsus, which is also oral semaglutide but licensed for type 2 diabetes at different strengths. If injections aren't for you, our page on Wegovy for weight loss explains the choices.
Getting genuine Wegovy safely in the UK
Because "wegovi" is a common misspelling, it turns up in some corners of the internet where the pens on offer aren't real medicine. The MHRA has repeatedly warned about fake weight-loss pens sold online and through social media; enforcement in 2025 saw around 20 million doses of illegally traded weight-loss medicines seized, with a street value near £45m, and the first illicit UK manufacturing site raided. Some counterfeit pens have contained the wrong drug entirely.
The safe route is simple in principle. Wegovy is prescription-only, so it should come from a pharmacy you can check on the register. Red flags to walk away from: any seller offering these pens without a clinical assessment, social-media sellers, and prices far below the going market rate. You can verify any UK pharmacy on the General Pharmaceutical Council register before you part with anything.
At nume, a real clinician reviews your consultation the same day, never software, and every order runs through our GPhC-registered pharmacy. You can read more about how we work and about our clinical team. Order before the 12pm cut-off on a weekday and, once a prescriber has approved you, treatment is dispatched the same day for free next-working-day tracked delivery. That's the whole point of a regulated route: genuine supply, real oversight, no guesswork.
If you'd like an honest read on suitability, speak to our prescribers and start with a free consultation.
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