Wegovy injection: the facts behind the headlines

The biggest myth: Wegovy injection is just a quick fix that stops working when you stop it

This is probably the most widespread misunderstanding, and it matters because it shapes whether people approach treatment realistically. Wegovy is not a temporary appetite suppressant in the way a short-course medicine might be. Semaglutide works by mimicking a naturally occurring gut hormone called GLP-1, which signals to the brain that you have eaten enough and slows the movement of food out of the stomach. Those are physiological processes, not willpower hacks.

What is true is that semaglutide's effects do diminish when treatment stops. Studies following participants after the STEP 1 trial found that a significant proportion of weight lost was regained within a year of stopping, without continued lifestyle support. Regulators and clinicians are clear that Wegovy is intended alongside a reduced-calorie diet and increased physical activity, not instead of them. That context matters when you read trial results: the roughly 15% average weight reduction seen in STEP 1 reflects a combined intervention, not the injection in isolation. The semaglutide treatment page goes into the mechanism in more detail if you want the science unpacked further.

The honest framing: Wegovy can be a highly effective tool for people who meet the clinical criteria. It is not a cure, and the prescriber's role includes reviewing whether continuing makes sense over time.

What the licensed UK schedule actually involves

The titration pathway is worth understanding before you start, because the early doses feel underwhelming by design. Treatment begins at 0.25 mg weekly, and if you want to read about what that starting point looks like in practice, the Wegovy 1 mg dose page covers what to expect as you move through the lower end of the schedule. That dose exists to let your digestive system adjust; it is not expected to drive meaningful weight change on its own. From there, the prescriber steps the dose upward roughly every four weeks (through 0.5 mg, 1.0 mg, 1.7 mg) to the standard 2.4 mg maintenance dose.

In January 2026, the MHRA approved a higher 7.2 mg maintenance dose, initially supplied as three 2.4 mg pens used in the same week; a dedicated single-dose 7.2 mg pen was then approved on 14 April 2026 for adults with a BMI of 30 or above. Trials at 7.2 mg reported average weight loss of around 20.7% over 72 weeks, which substantially narrows the gap with tirzepatide at its highest dose. Whether you progress to 7.2 mg is a clinical decision, your prescriber reviews your response and tolerability at each stage. Which dose and pen format is available to you is confirmed at consultation, not in advance.

On the practical side: the pen is refrigerated (keep it in the fridge door where you will see it, separate from food). Each pen contains four weekly doses. Injection sites rotate between the abdomen, thigh and upper arm; the Patient Information Leaflet covers the exact technique and storage windows, those details belong with the leaflet, not a webpage.

Who the UK licence covers, and what the NHS pathway actually involves

The licensed eligibility criteria for Wegovy in the UK are: adults aged 18 or over, with a BMI of at least 30, or at least 27 with one or more weight-related conditions such as high blood pressure, type 2 diabetes, dyslipidaemia or obstructive sleep apnoea. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance. A prescriber's clinical assessment takes in the whole picture, BMI alone does not determine suitability, and certain conditions or medicines require discussion before treatment begins.

NICE recommends semaglutide (Wegovy) for NHS use under TA875, but with conditions that make private treatment the realistic route for most people right now. The NICE recommendation is time-limited to a maximum of two years and applies only within a specialist weight management service providing multidisciplinary support. NHS waiting lists for those services are commonly long. Our full Wegovy guide covers the NHS versus private routes in plain terms, including what the NICE criteria mean in practice. For people who do not meet the current NHS thresholds or who do not want to wait, a private prescription from a regulated online pharmacy is the alternative, provided the pharmacy and prescriber are properly registered, which you can verify on the GPhC pharmacy register.

Side effects: what to expect and when to act

The most common side effects of Wegovy are gastrointestinal: nausea, vomiting, diarrhoea, constipation, indigestion and burping. These tend to be most noticeable in the first days after starting or stepping up the dose, and they often settle within a week or two. Fatigue, headache and dizziness are also reported. The frequently asked questions page addresses common concerns about managing these in the early weeks.

Some side effects need prompt medical attention. Severe stomach pain that spreads to the back (with or without vomiting) should be assessed urgently, as pancreatitis is a known, if infrequent, serious risk. The MHRA highlighted this in a Drug Safety Update for GLP-1 medicines in January 2026, and symptoms of gallbladder problems or signs of an allergic reaction also warrant same-day contact with a healthcare provider. Wegovy is not recommended during pregnancy, while breastfeeding, or if you are trying to conceive; it is not licensed for under-18s. These are conversations your prescriber will have with you during the assessment.

Suspected side effects can be reported directly to the MHRA via the Yellow Card scheme, a step the regulator actively encourages for Black Triangle medicines like Wegovy. If you have questions about a specific side effect you are already experiencing, our support team is available seven days a week.

When the clinical picture fits and treatment is well-managed, many people find Wegovy a meaningful part of a broader approach to weight and health. If you would like a prescriber to review whether it is right for you, check your eligibility with a free consultation.