Is Liraglutide the Same as Semaglutide?

Same class, different drugs, so what actually sets them apart?

GLP-1 (glucagon-like peptide-1) is a gut hormone released after eating. It signals fullness, slows stomach emptying, and nudges the pancreas to respond to blood sugar. Liraglutide and semaglutide both mimic this hormone, which is why the two names are so often confused. But mimicking the same hormone does not make two drugs interchangeable, any more than two antibiotics from the same family are the same pill.

Liraglutide has a shorter half-life (roughly 13 hours) which is why the weight-management dose (Saxenda, 3mg) must be injected every single day. Semaglutide's half-life is around a week, making a once-weekly injection feasible. That difference in how long each molecule stays active in the body shapes the entire dosing schedule, the size of the injection, and, to a significant degree, the results seen in clinical trials.

For a fuller comparison of these two medicines side by side, the liraglutide and semaglutide comparison page covers the evidence in more detail. The NHS medicines pages are also a reliable starting point for understanding each drug's pharmacology and licensed uses.

Are the clinical results the same, or does one work better?

The trial evidence is fairly clear. Semaglutide 2.4mg (Wegovy) was studied in the STEP 1 trial (68 weeks, roughly 2,000 adults with obesity, no diabetes) and produced an average body-weight reduction of around 15%, published in the New England Journal of Medicine. The SCALE trials for liraglutide 3mg typically found average reductions in the 5–8% range over 56 weeks.

That gap has largely determined how prescribing has shifted. Semaglutide's once-weekly schedule is also more practical for most people than a daily injection, and adherence tends to be higher when a routine is easier to maintain. Saxenda still has a clinical role (particularly where semaglutide is unsuitable for an individual patient) but in most private weight-management settings, semaglutide has become the default GLP-1 injection choice.

It is worth noting that semaglutide's results are themselves now being put in context by tirzepatide (Mounjaro), a dual GIP and GLP-1 receptor agonist. The question of which GLP-1 suits your situation is genuinely a clinical one, results depend on individual health history, not just headline trial averages.

Which of these medicines is actually licensed for weight loss in the UK?

Both carry a UK weight-management licence. Saxenda (liraglutide 3mg) is licensed for adults with a BMI of 30 or above, or 27 and above with at least one weight-related condition. Wegovy (semaglutide 2.4mg, and now up to 7.2mg following MHRA approval in early 2026) holds the same broad eligibility criteria, according to the NHS medicines page on semaglutide.

It is important to separate weight-loss licensing from diabetes licensing. Ozempic is also semaglutide, but it is licensed for type 2 diabetes, not weight management. Rybelsus is oral semaglutide, again for diabetes. Victoza is liraglutide for diabetes; Saxenda is liraglutide for weight loss. The brand name is your clearest guide to what a medicine is actually authorised to do.

nume dispenses Wegovy for weight management alongside tirzepatide (Mounjaro). Saxenda is not currently dispensed through our pharmacy. If your query is specifically about how semaglutide relates to the Wegovy brand, that page explains the relationship in plain terms. People considering which licensed injectable treatment suits them will find that a prescriber's assessment (not a comparison table) is the most useful tool.

If I was on Saxenda, can I switch to Wegovy instead?

Switching between liraglutide and semaglutide is a clinical decision, not a straightforward swap. They are different molecules at different receptor affinities, and the side-effect profile, even if similarly GI-led, may vary for an individual. A prescriber would look at why you were prescribed Saxenda, how well it worked, what dose you reached, and whether semaglutide's profile and schedule make sense for you now.

If you are currently on Saxenda and thinking about a change, the starting point is a conversation with whoever prescribed it. For people new to GLP-1 treatment who want to understand the broader landscape, the semaglutide overview covers how Wegovy works, what to expect, and the eligibility criteria a UK prescriber would apply. It is also worth being aware that certain medications can affect how semaglutide works in the body, and our page on what acts as a semaglutide inhibitor explains the interactions a prescriber would want to consider. The weight-loss treatments page gives an overview of the options currently available through regulated UK services.

A free consultation with one of our prescribers is the right place to ask these questions if you are considering Wegovy or Mounjaro. A real clinician reviews every consultation the same day, your answers go to a person, not a queue. If you are ready to explore your options, you can start your free consultation and get a same-day clinical assessment.