Is Wegovy or Saxenda Better for Weight Loss?

What the STEP and SCALE trials found about semaglutide versus liraglutide

The clearest picture of what Wegovy can do comes from the STEP 1 trial, published in the New England Journal of Medicine: 1,961 adults without diabetes, 68 weeks, semaglutide 2.4mg once weekly against placebo, alongside lifestyle support. Average weight reduction: approximately 15%. Participants who adhered fully did better still.

Saxenda's pivotal trial, SCALE, ran for 56 weeks and reported average losses of around 8% at the 3mg daily dose. The numbers sound comparable in structure, but the gap between 8% and 15% is clinically meaningful, that could be the difference between a comorbidity improving or not.

No large, randomised, head-to-head trial has directly compared semaglutide 2.4mg against liraglutide 3mg in the same population, so any side-by-side figure carries a caveat. What the indirect evidence consistently shows, and what NICE noted in its appraisal of semaglutide (TA875), is that semaglutide at the Wegovy dose produces meaningfully greater average weight reduction than liraglutide at the Saxenda dose. The NHS's own summary of semaglutide for weight loss reflects this position.

Mechanism partly explains it. Liraglutide activates the GLP-1 receptor only. Wegovy's active ingredient also acts through GLP-1, but at a longer-acting dose that allows once-weekly dosing, sustaining appetite suppression across the full week rather than requiring daily re-dosing to maintain the effect.

Practical differences that go beyond the percentage figures

The injection schedule is not a small thing. A daily injection for Saxenda versus a once-weekly one for Wegovy is a real-life difference, particularly over months. Adherence to daily regimens tends to slip over time. If you're thinking about which you'd actually keep up with on a busy week (a long weekend away, or the week payday lands and life accelerates) frequency of administration matters.

Titration schedules also differ. Saxenda starts at 0.6mg daily and increases weekly to the 3mg maintenance dose. Wegovy starts at 0.25mg weekly, stepping up over roughly 16 weeks to 2.4mg (and, since the MHRA approved a 7.2mg single-dose pen in April 2026, a higher maintenance option now exists for those who need it). Both escalate gradually to reduce gastrointestinal side effects, nausea in particular is common early on with both medicines.

Side-effect profiles are broadly similar: nausea, vomiting, diarrhoea, constipation, indigestion, and fatigue feature in both. These tend to be most noticeable after starting or after a dose increase, and usually settle within a week or two. The MHRA's January 2026 Drug Safety Update for GLP-1 medicines flagged acute pancreatitis as an infrequent but serious risk across the class, severe or persistent stomach pain that radiates to the back warrants urgent medical attention.

On cost context, Wegovy pricing in the UK private market has shifted considerably in recent years and varies by dose and provider. Saxenda historically sat at a lower price point, but cost alone is not a sound basis for choosing between two medicines with different efficacy profiles.

What is actually licensed for weight loss in the UK, and what nume provides

Both Wegovy (semaglutide) and Saxenda (liraglutide) hold UK licences for weight management. Ozempic, Rybelsus and metformin are sometimes mentioned in this context, but none are licensed for weight loss: Ozempic and Rybelsus are licensed for type 2 diabetes, and that distinction matters legally and clinically.

Saxenda is not dispensed at nume. The two weight-loss treatments available through our GPhC-registered pharmacy are Wegovy (semaglutide) and Mounjaro (tirzepatide). Mounjaro is the only dual GIP and GLP-1 receptor agonist licensed in the UK and produced the largest average weight reductions seen in any phase 3 weight-management trial to date. You can read a detailed look at how Wegovy and Saxenda compare on their own terms, or explore the broader evidence on semaglutide's effectiveness if that's the question you're working through.

Which medicine suits you depends on your medical history, current medications, BMI, and clinical goals, not on trial averages alone. A prescriber makes that call, not a comparison table. Our clinical team, led by our clinical director, reviews every consultation personally. If you'd like to understand whether Wegovy is appropriate for you, the right next step is a clinical conversation.

The question worth asking your prescriber instead

Rather than asking which medicine is better in the abstract, the more useful question is: which is better for you, given your circumstances? That depends on things the trial data cannot know about you, your history of GI sensitivity, other medicines you take, whether a daily or weekly injection is more practical, and what weight-related conditions your prescriber is looking to address.

Some people genuinely do better on liraglutide. For others, semaglutide's weekly schedule and larger average results make it the clearer choice. The evidence consistently favours semaglutide when the question is population-level efficacy, but the patient-level decision is always individual. You can read more about semaglutide as the active ingredient in Wegovy and review the key differences between Saxenda and Wegovy before your appointment. For more answers to common questions about these treatments, the nume FAQs cover the practicalities in plain language.

If you're considering Wegovy and want a same-day clinical review from a real prescriber, speaking to our prescribers is the place to start.