Switching from Saxenda to Wegovy: what actually changes and what to expect

The biggest misconception: you do not simply swap one pen for the other

The most common assumption people make is that switching from Saxenda to Wegovy is straightforward because both medicines are GLP-1 receptor agonists. The molecule is different, though. Saxenda contains liraglutide, injected daily; Wegovy contains semaglutide, injected once a week. Those are not interchangeable starting points. Liraglutide clears the body relatively quickly (its half-life is around 13 hours) whereas semaglutide stays active for roughly a week. That difference matters when a prescriber decides whether to stop one before starting the other, and at what dose to begin.

A prescriber will typically stop Saxenda before initiating Wegovy. There is no established fixed washout period in UK guidance, but most clinicians do not run them concurrently. The starting dose for Wegovy is 0.25 mg weekly, regardless of what dose of Saxenda you were on, the titration ladder resets. This can feel frustrating if you were stable on a high liraglutide dose, but it is the correct approach: semaglutide is a different molecule, and beginning at a tolerability dose reduces the chance of compounding gastrointestinal side effects.

If you are considering whether to switch from Saxenda to Wegovy, the practical first step is speaking to whoever currently prescribes your Saxenda, or starting a fresh consultation with a prescriber who can review your full history. Neither of these medicines should be started, stopped or swapped without clinical input.

What the evidence says about liraglutide versus semaglutide for weight loss

It is worth being clear about where the two medicines actually sit in the evidence, because the results from their respective trials are sometimes quoted out of context. The STEP 1 trial (semaglutide 2.4 mg, 68 weeks) showed an average body-weight reduction of around 15%, as published in the New England Journal of Medicine. Liraglutide's clinical trials showed lower average losses over comparable periods. These are not directly head-to-head comparisons (the populations and study designs differed) but NICE's appraisal process for both medicines reflects that semaglutide produces meaningfully greater average weight reduction.

The table below summarises the practical differences between the two medicines based on their UK licensed status and trial data:

One practical detail worth mentioning: Wegovy pens are refrigerated until you start using them, then can be kept at room temperature for a limited period per the patient information leaflet. Many people tuck the current pen in the fridge door and set a weekly phone reminder, simpler than a daily injection routine.

For a fuller side-by-side read, the Saxenda vs Wegovy comparison page goes into additional depth on mechanism, tolerability and who each medicine tends to suit.

Important: Saxenda is not dispensed by nume for weight loss

nume does not dispense Saxenda. This is not a regulatory gap on our part, it reflects a deliberate clinical focus. Saxenda holds a UK weight-management licence, but the evidence profile of semaglutide (Wegovy) and tirzepatide (Mounjaro) now represents the stronger option for most eligible adults, and those are the two medicines our GPhC-registered prescribers work with.

If you are currently taking Saxenda through another provider and want to explore whether switching to a licensed semaglutide treatment makes sense for you, a consultation with our prescribers is the right place to start. They can review your history, discuss whether Wegovy is appropriate, and manage the transition properly. People moving from another GLP-1 treatment are asked to provide evidence of their current prescription at the consultation stage, this is part of how we do things safely.

It is also worth knowing that NICE's recommendation for Wegovy (TA875) is tied to specialist weight management services on the NHS, with a maximum treatment duration of two years. Private treatment through a regulated pharmacy like ours is a different route, without a waiting list, and is open to clinically eligible adults regardless of NHS criteria. See the treatment options page to understand what is included.

If you have been on Ozempic and are thinking about a similar switch, the Ozempic to Wegovy page addresses that question directly, noting that Ozempic is licensed for type 2 diabetes, not weight loss, which changes the clinical picture.

What to expect if you do switch

Patients who switch from Saxenda to Wegovy sometimes expect the change to feel dramatic quickly. In practice, the first few weeks on the starting dose of semaglutide can feel underwhelming, the 0.25 mg dose is there to give your system time to adjust, not to produce immediate appetite suppression. Titration moves forward on a prescriber's schedule, typically in monthly steps. GI side effects (nausea being the most commonly reported) may resurface briefly when a new medicine starts, even if Saxenda had become well tolerated. They generally ease within the first few weeks at each dose level, as described on the NHS medicines page for semaglutide.

There is also the question of what happens to your weight during the transition period. Some people experience a short plateau or minor regain while they stop one medicine and wait to begin climbing the semaglutide ladder. This is normal and temporary, not a sign the switch is wrong. Keeping up with the diet and activity adjustments you have already made helps bridge the gap.

If you are also thinking about whether Mounjaro might suit you better than Wegovy, the switching from Mounjaro to Wegovy page covers that clinical question, or the weight-loss treatment overview explains both options side by side. Which medicine fits your situation is something our prescribers work through with you, not something a page can decide.