Everything about Wegovy: the complete picture for UK adults

Step 1, what Wegovy is and how it works in the body

Semaglutide is a GLP-1 receptor agonist: it binds to the same receptor that your gut hormone GLP-1 activates after eating, telling the brain that food has arrived. The practical result is reduced appetite, an earlier sense of fullness and slower gastric emptying. You eat less without the hunger signals that typically sabotage calorie reduction. That mechanism is why the medicine is described as addressing the biology of weight rather than demanding willpower alone.

Wegovy is the weight-management brand of semaglutide. Ozempic is also semaglutide, but it carries a diabetes licence, not a weight-loss one, and the two should never be treated as interchangeable. If you want a fuller picture before reading further, our introductory page on what Wegovy is is a good place to start. Our guide to semaglutide covers those differences in full.

The injectable form is a pre-filled pen, taken subcutaneously once a week, abdomen, thigh or upper arm, rotating the site each time. Treatment starts at 0.25mg, a low dose the body uses to adjust rather than to produce weight loss, and the prescriber increases it in steps, roughly monthly. The licensed maintenance dose has been 2.4mg; on 14 April 2026 the MHRA approved a dedicated single-dose 7.2mg pen for adults with a BMI of 30 or above, following trials in which participants lost an average of around 20.7% of body weight at that dose over 72 weeks. That's a meaningful shift in what the medicine can achieve at its ceiling.

Step 2, eligibility, the prescription process and what a clinical review checks

The licensed eligibility criteria for Wegovy are straightforward on paper: adults with a BMI of 30 or above, or 27 to 29.9 alongside at least one weight-related condition such as high blood pressure, high cholesterol, obstructive sleep apnoea, prediabetes or type 2 diabetes. Lower BMI thresholds can apply for people from South Asian, Chinese, Middle Eastern, Black African or African-Caribbean backgrounds, where a 2.5 kg/m² adjustment is recognised in UK guidance.

BMI meeting the threshold doesn't guarantee a prescription. A prescriber reviews the whole clinical picture: medical history, current medicines, contraindications and whether the medicine is appropriate for this person at this point. That is what a legitimate clinical assessment does. Through a regulated private service like ours, the consultation is free, reviewed the same day by a GPhC-registered Independent Prescriber, and paired with photo-ID and live weight verification before anything is dispensed.

Wegovy is not recommended during pregnancy, while breastfeeding or if you are trying to conceive. It is not licensed for under-18s. People with a history of medullary thyroid carcinoma or MEN2, or a history of pancreatitis, will need careful prescriber discussion before starting. The full contraindications list lives in the Patient Information Leaflet; if you're already taking other medicines, including oral contraceptives, the prescriber factors that into the assessment, there are specific guidance notes around oral contraception and tirzepatide in particular, though the current evidence for semaglutide is less definitive.

Step 3 (realistic results, what supports them and the new oral option

The STEP 1 trial (68 weeks, 2.4mg semaglutide) produced an average weight reduction of around 15%) a meaningful figure when sustained over more than a year. Results varied among participants, as they do in any trial, and the medicine works best alongside a reduced-calorie diet and increased physical activity, which is part of the licensed indication. It isn't a background supplement; it's a clinical tool that amplifies changes in eating behaviour. Protein intake, hydration and some resistance activity matter, especially when losing weight at speed.

If you are weighing up Wegovy against tirzepatide, the cost context page is a practical starting point for understanding what private treatment typically involves financially. For the clinical comparison between the two medicines, the evidence base (including the 2025 SURMOUNT-5 head-to-head trial) is worth reading carefully before drawing conclusions.

Everything above applies to the injectable. As of June 2026, there is also a Wegovy tablet, a once-daily oral option that reached UK approval on 11 June 2026, making the UK the first country in Europe to licence it for weight management. The maintenance dose is 25mg daily, reached through a titration starting at 1.5mg. In the phase 3 OASIS 4 trial, participants lost an average of around 13.6% of body weight over 64 weeks, rising to about 17% among those who stayed fully adherent throughout. No refrigeration needed, which makes it a practical option for frequent travellers or anyone who'd rather not have a pen in the fridge door alongside the milk every week. It's private prescription only at this stage, with no NICE appraisal yet completed.

Step 4, side effects, safety monitoring and when to get medical help

The most commonly reported side effects are gastrointestinal: nausea, vomiting, diarrhoea, constipation, reflux and burping sit at the top of the list. Most people notice these most strongly at the start or after a dose increase, with symptoms settling within days to two weeks for the majority. Fatigue, headache, dizziness and injection-site reactions are also reported. The NHS semaglutide medicines page sets out the full side-effect profile clearly.

A small number of more serious effects require prompt attention. Acute pancreatitis (severe stomach pain that can radiate to the back, with or without vomiting) is a known but infrequent risk; get urgent medical help if that pattern appears. Gallbladder symptoms, signs of dehydration from prolonged GI illness, or any allergic reaction also warrant same-day contact with a healthcare professional. If you notice low mood or thoughts of self-harm at any point, speak to your GP or call 111.

Patients can report suspected side effects directly through the MHRA's Yellow Card scheme, and are encouraged to do so, it's how the safety picture of newer medicines like Wegovy improves over time. Our key things to know about Wegovy page covers the practical day-to-day questions our prescribers hear most often, and our guide to weight regain after stopping addresses what happens if treatment ends. If you'd like to go through your personal situation with a clinician, speaking to our prescribers is the right next step.