The most important things to know about Wegovy before you begin

How does Wegovy actually change the way you feel about food?

The mechanism is hormonal rather than purely behavioural. Semaglutide mimics GLP-1, a gut peptide released after eating. It signals to the hypothalamus that the stomach is fuller than it is, and it slows the rate at which food moves through the gut. The result, for most people, is that hunger arrives later, feels less urgent and is satisfied by smaller portions. This is not a willpower boost, it is a physiological shift, which is why so many people find the medicine feels quite different from dieting alone.

There is also an effect on food reward. Many patients describe losing interest in foods they previously found difficult to resist. The semaglutide treatment overview on our site sets out the full pharmacology, but the headline is simple: the medicine changes the signal, not just the behaviour. Understanding that distinction matters for managing expectations, and our guide to the key things to know about Wegovy is a good place to build that understanding before you go further. Weight loss with Wegovy is typically gradual and progressive rather than immediate, and the first weeks at the lower starter doses are largely about tolerability rather than rapid change.

The NHS patient information page for semaglutide offers a clear lay explanation of how the medicine works, which is worth reading alongside the leaflet that comes with your pen.

Who does the UK licence actually cover, and what does that mean in practice?

The UK licence covers adults with a BMI of 30 or above, or a BMI of 27 to 29.9 alongside at least one weight-related condition such as high blood pressure, raised cholesterol, type 2 diabetes, obstructive sleep apnoea or prediabetes. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance, your prescriber will factor that into their assessment.

Meeting the BMI number is not enough on its own. A prescriber also considers your medical history, current medicines and any contraindications before approving treatment. Wegovy is not licensed for use during pregnancy, while breastfeeding or for people trying to conceive, and it is not licensed for anyone under 18. People with a personal or family history of medullary thyroid carcinoma or MEN2 syndrome should not take it.

If you are thinking about whether Wegovy could be right for your situation, the things to know before starting Wegovy guide covers the practical preparation steps and contraindications in more detail. A prescriber's assessment is always the deciding factor, not a self-scored checklist.

What side effects do most people actually encounter?

The side-effect profile is dominated by gastrointestinal symptoms. Nausea is the most common, particularly in the first few weeks and after each dose step. Diarrhoea, constipation, vomiting, reflux and bloating are also reported. For most people these settle within one to two weeks of a given dose, and our guide to what to expect when you first start Wegovy explains how moving slowly through the titration schedule reduces how pronounced they feel.

Less common but more serious effects include acute pancreatitis. In January 2026 the MHRA issued a Drug Safety Update highlighting this as a known risk for GLP-1 medicines generally, the key warning sign is severe, persistent stomach pain that spreads to the back, with or without vomiting. That requires urgent medical attention, not a wait-and-see approach.

Gallbladder problems, injection-site reactions, fatigue and headache also appear in trial data. Suspected side effects can be reported directly to the MHRA at the Yellow Card scheme, and patients are encouraged to do so, it is how the post-market safety picture stays current. If you have questions about a specific symptom after starting, the nume aftercare team is available seven days a week.

Is Wegovy available on the NHS, and what does private treatment look like?

On the NHS, Wegovy (approved under NICE TA875) is available through specialist weight management services, subject to strict criteria, including a BMI of at least 35 with a weight-related comorbidity, a maximum treatment duration of two years, and access to multidisciplinary support. Waiting times through those pathways are often long. Scotland, Wales and Northern Ireland operate different access frameworks.

Private treatment through a registered online pharmacy is a separate route, with no referral or waiting list, provided clinical assessment confirms suitability. If cost is part of your thinking, the Wegovy price comparison guide explains what typical private treatment involves financially and what a legitimate price should include. A genuine private prescription always involves clinical review, that is not optional, and any offer that sidesteps it is a red flag.

There is also a newer option worth knowing about: the Wegovy treatment page covers the 7.2mg single-dose pen approved by the MHRA in April 2026, as well as the oral semaglutide tablet approved in June 2026 for people who prefer not to inject. Both routes still require a prescriber's sign-off. If you are unsure which option fits your circumstances, the weight loss treatment overview sets out how the different medicines compare so you can have a more informed conversation when you do speak to a clinician.

It is completely understandable to feel uncertain at this stage. Most people researching Wegovy are weighing up a real decision, not just browsing, and having the right information before that consultation makes the conversation more useful. When you are ready, you can start your free consultation and a GPhC-registered prescriber at our pharmacy will review your case the same day.