Changing from Saxenda to Wegovy: what the clinical evidence shows

Why the trial results make semaglutide worth considering after liraglutide

The clinical case for switching starts with the head-to-head numbers. The STEP 1 trial, published in the New England Journal of Medicine, randomised 1,961 adults without diabetes and found average weight loss of around 15% at 68 weeks on semaglutide 2.4mg, compared with roughly 5–7% typically reported for liraglutide 3mg. That gap matters in practice. People who have plateaued on Saxenda, or who lost less weight than hoped, often ask about Wegovy precisely because the published evidence points to a larger effect.

There is also a practical quality-of-life angle. Saxenda is injected every day; Wegovy is once weekly. For anyone who finds daily injections a burden, that difference alone can shift adherence. Neither point is a guarantee (individual responses vary) but the evidence-based rationale for the conversation is clear. The full comparison of Wegovy and Saxenda covers the clinical differences in more detail if you want to look at them side by side before speaking to a prescriber.

One misconception worth clearing up gently: some people assume the two medicines are interchangeable because both are GLP-1 agonists. They are not. They bind the same receptor but are structurally different molecules with different pharmacokinetics, different dose escalation schedules, and, in clinical practice, meaningfully different outcomes. Knowing both are GLP-1s is useful context, it is not a reason to treat the switch as simple.

What stopping Saxenda and starting Wegovy looks like in practice

UK guidance does not set a mandatory washout period between stopping liraglutide and starting semaglutide. In practice, most prescribers review the individual's current dose, how long they have been on it, and any ongoing side effects before deciding on timing. Starting Wegovy immediately after Saxenda is clinically plausible for many people, but that decision belongs with the prescriber, not a protocol checklist.

Wegovy begins at 0.25mg weekly and is titrated upward (0.5mg, 1.0mg, 1.7mg, 2.4mg) approximately every four weeks, as set out in the product's summary of characteristics on the electronic Medicines Compendium. The titration exists to manage gastrointestinal side effects, which are most noticeable early on or after a dose increase. People switching from Saxenda should not expect to skip ahead in the schedule because their body has experienced a GLP-1 before; the prescriber assesses whether any acceleration is appropriate, and everything you need to know about that process is covered in our guide to moving from Saxenda to Wegovy.

Side effects common to both medicines include nausea, vomiting, diarrhoea, constipation, and fatigue. These typically ease within days to a couple of weeks of starting or increasing a dose. If you are planning a switch, it is worth discussing with your prescriber what to do if GI effects are more pronounced than expected, not to alarm you, but because knowing the plan in advance makes the early weeks easier to manage.

Saxenda is not dispensed by nume for weight loss, here is what is

Saxenda is not a medicine nume dispenses. It is licensed in the UK for weight management, but our formulary covers Wegovy (semaglutide injection) and Mounjaro (tirzepatide), both of which hold UK licences for weight management in adults. If Saxenda is what brought you here, the more practical question is probably which of those two options suits your situation.

Wegovy injection is a once-weekly subcutaneous injection titrating to 2.4mg, with a newer 7.2mg maintenance dose approved by the MHRA in January 2026 for people with obesity (BMI 30 or above). Mounjaro is the only licensed dual GIP and GLP-1 receptor agonist available in the UK, with SURMOUNT-1 trial evidence showing around 20–21% average weight loss at the 15mg dose over 72 weeks. Both are prescription-only medicines; neither is appropriate for everyone, and clinical assessment determines which, if either, is right for you.

A useful starting point is our Wegovy overview, which covers the full dose schedule, eligibility criteria, and what the treatment process involves, including practical details such as changing your Wegovy injection day if your weekly schedule needs to shift. If cost is part of the picture, our Wegovy pricing guide explains what a legitimate private prescription includes, honestly. For people who previously asked about switching from Ozempic rather than Saxenda, the considerations are covered separately.

How to arrange a switch through a private online pharmacy

If you have been on Saxenda through a private provider and want to move to Wegovy, the route through nume is the same as for any new patient: a free consultation reviewed the same day by a GPhC-registered Independent Prescriber, not a decision system. You will be asked about your current or recent treatment, current weight, relevant medical history, and any medicines you take alongside, the kind of information that determines whether Wegovy is suitable and at what starting dose.

Verification is part of the process too: photo ID, live weight check, and, where relevant, evidence of your current treatment. That is not bureaucracy for its own sake; it is what responsible prescribing looks like when a prescription-only medicine is involved. You can verify any online pharmacy, including ours, on the GPhC register. Our GPhC premises registration number is 9012878.

Our clinical team's approach to these transitions is explained on the clinical team page. If you have questions before starting a consultation, the FAQs cover common ones, or you can reach the team directly via our contact page. When you are ready, start your free consultation and let our prescribers take it from there.