How Saxenda is different from Wegovy — and why it matters for your treatment

You've read about both and you're wondering which is the stronger option

It's a reasonable question. Saxenda arrived in UK clinics before Wegovy, so many people encountered it first, through their GP, a weight-management clinic, or a friend who'd been on it. Then Wegovy appeared, the headlines followed, and now the comparison feels important to untangle.

Both medicines belong to the same drug class: GLP-1 receptor agonists. They mimic a gut hormone called GLP-1, which signals fullness to the brain, slows the rate at which the stomach empties, and reduces appetite. The mechanism is the same family. The medicines are not.

Saxenda's active ingredient is liraglutide, a molecule developed originally for type 2 diabetes (as Victoza). It requires a daily injection, because liraglutide has a shorter half-life and clears from the body relatively quickly. Wegovy's active ingredient is semaglutide, a chemically modified version of the same GLP-1 molecule that lasts far longer in the body, long enough for one injection a week to maintain its effect. For most people, that weekly schedule is easier to keep to. The NHS's own medicines guidance on semaglutide reflects the once-weekly dosing clearly. If you want to understand how the two molecules differ beyond their dosing frequency, our page on liraglutide vs semaglutide goes into more depth.

What the evidence shows when you compare the two directly

The SCALE trial programme (liraglutide 3mg, 56 weeks) found an average weight reduction of around 8% in adults with obesity. The STEP 1 trial (semaglutide 2.4mg, 68 weeks) found an average reduction of approximately 15%, published in the New England Journal of Medicine. A direct head-to-head study (STEP 8) confirmed semaglutide's advantage over liraglutide in a controlled setting: roughly twice the weight loss over the same period.

That gap is clinically meaningful, not a rounding difference. It's one reason NICE's appraisal of semaglutide (Wegovy) gave it a positive recommendation for NHS use in specialist weight management services, while liraglutide's position in NHS guidance has become more limited as semaglutide evidence grew. You can read NICE's full guidance on semaglutide (TA875) for the committee's reasoning.

Wegovy's dosing also continues to evolve. The MHRA approved a higher 7.2mg maintenance dose in early 2026, and a dedicated single-dose 7.2mg pen was cleared in April 2026, nudging Wegovy's peak results even closer to those seen with tirzepatide. If you're curious how Wegovy's different dose levels compare, our guide to Wegovy's dose steps explains the titration journey.

What's actually licensed for weight loss in the UK right now

Both Saxenda and Wegovy hold UK marketing authorisations for weight management. Saxenda is licensed for adults with a BMI of 30 or above, or 27 or above alongside a weight-related condition. Wegovy shares similar eligibility thresholds. Neither is suitable during pregnancy or breastfeeding, and neither is licensed for anyone under 18.

The difference you'll encounter in practice is availability and clinical positioning. Saxenda is not dispensed by nume. The medicines nume's prescribers work with for weight loss are Wegovy (semaglutide injection) and Mounjaro (tirzepatide), both of which hold current UK licences for weight management and are dispensed through our GPhC-registered pharmacy (GPhC premises registration 9012878). If you want a broader view of how semaglutide fits into the UK weight-loss landscape, our semaglutide overview covers the picture.

Wondering about the cost side of things? Our Wegovy treatment page sets out what private prescribing includes. One transparent price covers consultation, prescription, and free next-working-day delivery, no subscription, no hidden charges.

Practical differences worth knowing before you speak to a prescriber

Daily vs weekly injections is the most obvious contrast, but there are subtler differences too. Liraglutide's side-effect profile and semaglutide's are broadly similar (nausea, loose stools, reduced appetite) because the mechanism is shared. The GI effects tend to be most noticeable after starting or after a dose step upward, then settle for most people within the first two weeks at each level.

Storage is the same family of requirement: both need refrigeration between 2°C and 8°C. Many people keep the current pen on the fridge door alongside everyday items, convenient, consistent, and the right temperature. The Patient Information Leaflet for whichever medicine you're prescribed gives the exact room-temperature window if you're travelling; don't rely on general guidance for that detail.

Which medicine suits your situation is a clinical decision. The right starting point is a conversation with a prescriber who can look at your medical history, current medications, and what you've already tried. Our clinical team reviews every consultation the same day, and if you'd like to read about how Ozempic differs from Wegovy before you do, that page helps clarify a question that comes up often. Equally, if you're trying to get your head around the different semaglutide products available, our overview sets out how each one is positioned. If you'd like to explore whether Wegovy or Mounjaro is the right fit for you, speaking to our prescribers is the natural next step.