Wegovy v Saxenda: How These Two GLP-1 Injections Actually Compare

Step 1: Know what each medicine actually is

Saxenda is the brand name for liraglutide, manufactured by Novo Nordisk. It is a GLP-1 receptor agonist, meaning it mimics a gut hormone that signals fullness to the brain and slows how quickly food leaves the stomach. Injected once daily, its dose is gradually increased over five weeks from 0.6 mg up to the 3 mg maintenance level.

Wegovy is the brand name for semaglutide, also made by Novo Nordisk, but semaglutide is a different molecule. It binds more tightly to the GLP-1 receptor and stays active in the body for much longer, which is why it needs only a once-weekly injection. The titration runs over roughly four months, starting at 0.25 mg and climbing through four steps to the 2.4 mg maintenance dose. The semaglutide medicine overview covers the mechanism in more detail if you want the science behind that extended half-life.

A common source of confusion is the relationship between Wegovy and Ozempic. Both contain semaglutide, but Ozempic is licensed for type 2 diabetes management, not weight loss. Wegovy is the weight-management licence. They are not interchangeable on a prescription, regardless of what a seller may imply. The Wegovy overview page explains the distinction clearly.

Saxenda and Wegovy are therefore not the same medicine. They share a mechanism class but differ in active ingredient, injection frequency, dose range, and the evidence base behind their weight-loss results.

Step 2: Compare the trial evidence on weight loss

Trial results set the two apart quite sharply. In the SCALE Obesity and Prediabetes trial, liraglutide 3 mg produced an average weight reduction of around 8% over 56 weeks in adults without diabetes. Semaglutide 2.4 mg, studied in the STEP 1 trial over 68 weeks in a comparable population, produced an average reduction of approximately 15%, as reported in the STEP 1 publication in the New England Journal of Medicine.

That is a meaningful gap, and it has shaped how UK regulators and clinicians discuss the two options. NICE recommended semaglutide (Wegovy) for use within specialist NHS weight management services following its TA875 appraisal. Liraglutide (Saxenda) was previously recommended but that recommendation has been superseded in most NHS contexts by the newer, more effective option.

If you are weighing up which performed better in more detail, the is Wegovy or Saxenda better page sets out the evidence comparison without the jargon, and the full Saxenda and Wegovy comparison puts both medicines in a structured table.

One practical check you can do right now: look at any Saxenda or Wegovy listing you are considering and confirm the seller's GPhC registration number on the GPhC pharmacy register — it takes under a minute and tells you immediately whether the pharmacy is regulated.

Step 3: Consider side effects, suitability, and what the prescriber weighs up

The side-effect profiles of Saxenda and Wegovy overlap substantially. Nausea, vomiting, diarrhoea, constipation and indigestion are the most commonly reported effects for both, tending to peak in the first few weeks of treatment or after a dose increase before settling. Injection-site reactions, headache and fatigue also appear in both medicines' data.

Neither is recommended during pregnancy, while breastfeeding, or when trying to conceive. Both require a clinical assessment to rule out contraindications including a personal or family history of medullary thyroid carcinoma or MEN2 syndrome, and certain gastrointestinal conditions. The NHS semaglutide medicine page covers semaglutide's side-effect and caution profile in plain language and is worth reading before any consultation.

Switching from Saxenda to Wegovy is something some patients ask about, particularly those who started liraglutide before semaglutide was widely available. That is a clinical decision, not one to make independently. The saxenda to wegovy question comes up regularly, and the answer depends on your current dose, response, and any comorbidities your prescriber will factor in. Equally, the question of whether the two can be used simultaneously comes up, they cannot; the page on taking Saxenda and Wegovy together explains why combining two GLP-1 agonists is not clinically appropriate.

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

Both Saxenda (liraglutide) and Wegovy (semaglutide injection) hold UK weight-management licences. Mounjaro (tirzepatide) is also licensed and acts on two receptors rather than one, which is why its trial results sit above either semaglutide or liraglutide in head-to-head and indirect comparisons. A full comparison of all available options is on the weight-loss treatments overview.

nume is a GPhC-registered online pharmacy (registration number 9012878, verifiable at the GPhC register) that prescribes and dispenses Wegovy and Mounjaro for weight management. We do not currently dispense Saxenda. If you are exploring whether Wegovy is the right fit for you, understanding what Wegovy costs privately in the UK is a useful next step before starting a consultation. Every consultation at nume is reviewed the same day by a GPhC-registered Independent Prescriber, a real clinician reads your details, not an automated system. If clinically suitable, treatment is dispatched the same working day for free next-working-day delivery.

To find out whether Wegovy or Mounjaro is appropriate for your situation, the starting point is a free consultation with our clinical team. Check your eligibility and start that conversation here.