The difference between Saxenda and Wegovy, explained clearly

What the clinical evidence actually shows for each medicine

The most important starting point is the trial record. The SCALE Obesity and Prediabetes trial, published in the New England Journal of Medicine, studied liraglutide 3mg (Saxenda) over 56 weeks and found an average body-weight reduction of around 8% versus around 2.6% on placebo — a meaningful result at the time of approval. Then came the STEP 1 trial for semaglutide 2.4mg (Wegovy): 68 weeks, an average reduction of roughly 15% against placebo's ~2.4%, in nearly 2,000 adults with obesity or overweight and at least one weight-related condition. That gap (roughly 8% versus 15% average loss) is why the two medicines occupy different positions in clinical practice today. NICE's appraisal process reflects this: semaglutide (Wegovy) holds a formal positive recommendation for NHS use under NICE TA875, while liraglutide's weight-loss licence predates the current NICE technology appraisal framework for obesity medicines. Neither figure is a guarantee for any individual; biology, adherence and lifestyle all shape real-world outcomes. What the data do establish is a consistent, reproducible difference in average effect size across large randomised populations.

Different molecules, different daily realities

The pharmacological difference matters too. Liraglutide is a GLP-1 analogue with a half-life of roughly 13 hours, which is why Saxenda requires a daily injection, missing a dose affects levels quickly. Semaglutide's half-life is approximately seven days, making a once-weekly injection schedule feasible and forgiving if a day or two slips. That distinction has a real effect on how people fit treatment into their lives. A daily injection demands more routine discipline than a weekly one; some patients manage it without difficulty, while others find the frequency a barrier to long-term adherence. For Wegovy, many patients keep their pen in the fridge and pick a consistent day each week (Monday morning before the kettle boils, or Sunday evening) and build the injection around that anchor. Saxenda requires finding that moment every single day. On the question of the what is the difference between Wegovy and Saxenda in terms of mechanism, both activate GLP-1 receptors to slow gastric emptying and reduce appetite, so the pathway is shared; the molecule, half-life and dosing rhythm are where they diverge. If you are also wondering whether there is any difference between Ozempic and Wegovy, given that both contain semaglutide, our dedicated guide walks through exactly how the two relate to each other. You can read more about how Wegovy works and what to expect from the medicine in our dedicated guide.

Eligibility, licensing and who each medicine is approved for in the UK

Both medicines carry a UK licence for weight management in adults with a BMI of 30 or above, or 27 or above alongside at least one weight-related condition such as high blood pressure, raised cholesterol or type 2 diabetes. The licensed age group is adults (18 and over); neither is recommended during pregnancy, breastfeeding or while trying to conceive. Beyond that shared frame, the two medicines differ in their NICE-recommended populations. Under TA875, Wegovy is recommended within specialist weight management services for a maximum of two years; liraglutide does not currently have an equivalent NICE TA for weight management, meaning NHS access routes differ substantially. For people exploring private treatment, the range of licensed weight-loss medicines available is broader, but a prescriber still needs to assess which option fits your history, comorbidities and preferences. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance, a detail our prescribers factor in at clinical review. It is also worth knowing that Ozempic (also semaglutide) is licensed for type 2 diabetes, not weight loss, a distinction that causes genuine confusion online.

What this means if you are considering either medicine, and what nume can offer

Saxenda is not a medicine nume currently dispenses. This page is here to answer the comparison question honestly, not to sell you one path over another. If your research has led you here from a Saxenda starting point, the evidence-based picture is that semaglutide (Wegovy) shows stronger average outcomes in trials, is available as a once-weekly injection, and holds a NICE positive recommendation, which is why it sits in our formulary. Mounjaro (tirzepatide), the only dual GIP and GLP-1 receptor agonist licensed in the UK for weight management, produced even larger average losses in the SURMOUNT-1 trial; comparing it with semaglutide directly is covered on our Mounjaro versus Wegovy page. There is also now a once-daily oral semaglutide option for people who prefer not to inject. If cost is part of your thinking, our guide to Wegovy pricing in the UK explains what a legitimate private prescription actually includes. For anyone ready to discuss their options, a free consultation with our prescribers is the right next step, which of these medicines suits you is a clinical decision made with you, not for you.