Wegovy vs Saxenda: what is the difference?

Obesity is an increasingly common health condition in the UK and around the world. In recent years new medications to aid weight loss have become available, and the battle to lose weight may finally be getting easier. However, not all weight loss medications are the same and it can be difficult to know which one is right for you.

Both liraglutide and semaglutide, sold under the brand names Victoza and Ozempic, started out as diabetes drugs. These were used to stabilise blood glucose levels in people with type 2 diabetes. However, many people taking these medications found that they also lost weight, and following clinical trials in 2014, liraglutide was approved for use in the US for the treatment of obesity under the brand name Saxenda. In the UK, Saxenda was approved for use by the NHS in 2020.

More recently, semaglutide was approved for use under the brand name Wegovy. Semaglutide is also available in tablet form under the brand name Rybelsus.

Saxenda and Wegovy are made by the pharmaceutical company Novo Nordisk and work in similar ways, but there are some differences, namely in the dosage and how often they need to be injected.

Wegovy and Saxenda are both prescription medications that can aid weight loss as part of a calorie controlled diet. They are given by injection just under the skin. Though Wegovy and Saxenda contain different active ingredients, they both work in similar ways by targeting the area of the brain responsible for regulating appetite. When we eat, our bodies naturally produce a hormone called glucagon-like peptide 1 (GLP-1) that helps control our appetite and regulate blood sugar levels. Wegovy and Saxenda mimic this hormone and make us feel less hungry so that we eat less. They also keep food in your stomach for longer so that you feel fuller between meals.

Both Saxenda and Wegovy are used to aid weight loss in adults aged 18 and over with a body mass index (BMI) of 30 or above, or 27 and above if they have weight related medical conditions like type 2 diabetes, high blood pressure, or high cholesterol. To be effective, these medications should be taken in addition to a reduced calorie diet and increased physical activity.

The main difference between Wegovy and Saxenda is that while Saxenda needs to be injected once a day, Wegovy lasts longer in the body and is given as a weekly injection.

Both Wegovy and Saxenda are injected in gradually increasing doses until the maximum dose is reached. This is to minimise gastrointestinal side effects.

Wegovy starts at a weekly dose of 0.25 mg, increasing every 4 weeks over the next 17 weeks to the maximum dose of 2.4mg

Saxenda starts at a dose of 0.6mg per day, increasing every week over the next 5 weeks to the maximum dose of 3mg.

Wegovy contains the active ingredient semaglutide and Saxenda contains the active ingredient liraglutide.

A 2018 study comparing Wegovy and Saxenda found that Wegovy is more effective in aiding weight loss than Saxenda. After the year long study was complete, participants taking Wegovy had an average weight loss of around 11.2 to 13.8% of their body weight compared to participants taking Saxenda who lost around 7 to 8% of their starting body weight.

Wegovy and Saxenda both come from the same family of medications called GLP-1 receptor agonists and have similar side effects.

Most side effects are gastrointestinal (relating to the stomach and digestive system) and usually improve after a few weeks. If your side effects are causing you distress, getting worse, or not going away, seek medical advice from your GP or healthcare provider.

Common side effects of both Wegovy and Saxenda include:

• nausea (feeling sick)
• vomiting (being sick)
• abdominal (stomach) pain
• diarrhoea (frequent, loose, or watery poo)
• constipation
• low blood sugar (hypoglycemia) in people with type 2 diabetes
• headache
• dizziness
• feeling tired or lacking energy
• indigestion
• gas and bloating
• dry mouth
• changes in your sense of taste
• urinary tract infections (UTI)
• local reactions (pain, swelling, bruising) at the injection site
• anxiety
• insomnia

Warnings and serious side effects

Both Saxenda and Wegovy carry warnings due to an increased risk of some thyroid tumours. You should not take these medications if you or a close family member has or has ever had thyroid cancer, or a condition called multiple endocrine neoplasia syndrome type 2 (MEN 2).

In addition, clinical trials for Saxenda showed a possible link between liraglutide and inflammation of the pancreas (pancreatitis). You should stop taking Saxenda immediately if you develop pancreatitis while taking it. Symptoms of pancreatitis include sudden, severe abdominal (stomach) pain, nausea, vomiting, high temperature (fever), and diarrhoea. Seek immediate medical attention if you develop any of these symptoms while taking Saxenda.

Other rare, but serious side effects include gallbladder problems and severe allergic reactions. Seek immediate medical attention if you have any of the following symptoms:

• Swelling of the face, lips, and tongue, itchy rash, difficulty breathing, fast heart rate.
• Pain in your upper abdomen, fever, jaundice (yellowing of the skin or the whites of your eyes), or clay-coloured stools.

No. Since Wegovy and Saxenda work in the same way, it`s not safe to take them at the same time. Taking Wegovy and Saxenda together could make your blood sugar drop too low and may make side effects worse. To decide which medication is right for you, talk to your GP or healthcare provider.

If you are currently taking Saxenda and would like to try Wegovy, the first step is to make an appointment with your GP. Your GP can discuss the pros and cons of each treatment option and discuss which one is best for you. If you do decide to switch medications, it’s important to do so safely.

If you are switching from Saxenda to Wegovy you can take your first Wegovy injection at least 24 hours after your last injection of Saxenda. If you are switching from Wegovy to Saxenda you should wait at least 5 weeks after your last Wegovy injection before starting Saxenda. Always follow the instructions given by your GP or healthcare provider carefully when taking any medication.