Wegovy's medical name is semaglutide — here's what that means for you

Why clinical trials used the name semaglutide, not Wegovy

The landmark STEP 1 trial, published in the New England Journal of Medicine, studied semaglutide 2.4 mg administered once weekly in adults with obesity. Over 68 weeks, participants lost an average of around 15% of their body weight compared with placebo. That figure is attached to the molecule (semaglutide) not to any brand. Regulatory agencies including the MHRA assess medicines by their active substance; Wegovy's approval rests on that semaglutide evidence base.

This matters practically. When a GP or prescriber writes a prescription, they may write the brand name or the generic name. When NICE published its appraisal TA875, the document refers throughout to semaglutide, not Wegovy, because the recommendation is about the compound. Understanding that the two names refer to the same thing prevents confusion when you read clinical guidance, your prescription, or the Patient Information Leaflet.

It is also worth knowing that semaglutide exists in more than one product. Ozempic (semaglutide at lower weekly doses: 0.5 mg and 1 mg) is licensed for type 2 diabetes, not for weight management. Rybelsus is an oral form of semaglutide at 3 mg, 7 mg and 14 mg, again for type 2 diabetes only. None of those products should be sought, or used, for weight loss. The full picture of semaglutide's different licensed uses is worth reading if you have seen multiple product names and are not sure which applies to you.

How semaglutide acts, the biology behind the brand

Semaglutide is a GLP-1 receptor agonist. GLP-1 (glucagon-like peptide-1) is a hormone your gut releases after eating; it signals to the brain that you have had enough, slows the rate at which your stomach empties, and influences insulin release. Semaglutide mimics and extends that signal. The result, across the clinical programme, was a consistent and meaningful reduction in appetite and caloric intake, not through willpower, but through a hormonal pathway that weight alone cannot reset.

The NHS medicines page for semaglutide describes this mechanism and the full side-effect profile in plain language. Common effects are gastrointestinal in character: nausea, constipation, indigestion and diarrhoea are the most frequently reported, particularly in the early weeks of treatment or after a dose increase. For most people they are manageable and tend to ease as the body adjusts. Rarer but more serious concerns (including acute pancreatitis) mean that treatment starts at a low dose and is increased gradually, under prescriber oversight. If you experience severe, persistent stomach pain that travels to your back, seek medical advice promptly.

If you are thinking about exploring weight-loss treatment options, understanding the biology is a useful starting point, it sets realistic expectations and helps you have an informed conversation with a clinician.

Who the UK licence covers, and where semaglutide sits now

Wegovy (semaglutide injection) is licensed in the UK for adults with a BMI of 30 or above, or a BMI of 27 to 29.9 with at least one weight-related health condition such as high blood pressure, high cholesterol, obstructive sleep apnoea or type 2 diabetes. A BMI alone does not determine whether treatment is appropriate; a prescriber looks at the whole clinical picture, including your medical history and any medicines you already take.

In June 2026, the MHRA also approved semaglutide in tablet form under the Wegovy brand for weight management, the first oral GLP-1 medicine to reach that approval in the UK. The tablet licence covers adults with a BMI of 30 or above, or 27 to 29.9 with a weight-related condition. The dosing schedule runs from 1.5 mg daily up to a 25 mg maintenance dose, and the tablets do not require refrigeration, which changes the logistics of treatment for many people.

On the NHS, access to injectable Wegovy is governed by NICE TA875, which restricts it to specialist weight management settings and sets a two-year maximum duration, alongside specific BMI and comorbidity thresholds. Waiting lists in many areas are long. Private prescribing through a regulated online pharmacy offers an alternative route for people who meet the clinical criteria but are not able to access NHS services quickly, or who simply prefer a different path. Details of what that involves are on the guide to obtaining Wegovy in the UK.

Semaglutide by any name: what to look for in a legitimate supply

If you have already been searching and have seen semaglutide offered without a prescription on social media or from unfamiliar websites, that is a red flag. The MHRA has warned publicly about counterfeit weight-loss pens; fake products seized in enforcement operations have in some cases contained insulin rather than semaglutide, with serious consequences for people who used them. The only safe route is a prescription issued following a real clinical assessment, dispensed by a pharmacy you can verify on the GPhC register.

If you are curious about how semaglutide compares with other molecules (including tirzepatide, which acts on both GLP-1 and GIP receptors) the overview of semaglutide's licensed names and forms covers that ground, and if you want to understand one specific manufacturer's formulation in more detail, our guide to Deus Medical semaglutide explains what that product involves. The clinical question of which medicine suits you is one our prescribers work through individually at consultation. If you think semaglutide might be right for you, checking your eligibility is the straightforward next step, it starts with a free consultation, reviewed that day by a GPhC-registered Independent Prescriber, not software.