Saxenda vs Wegovy

Two substances from the same maker

Saxenda contains liraglutide and Wegovy contains semaglutide, and Novo Nordisk makes both. The Saxenda SmPC describes liraglutide as an acylated human GLP-1 analogue that "binds to and activates the GLP-1 receptor". The Wegovy SmPC describes semaglutide as a GLP-1 analogue that "acts as a GLP-1 receptor agonist". The NHS medicines guide calls each of them a GLP-1 agonist.

Daily and weekly injections

Saxenda is injected once a day. Its SmPC says it "is administered once daily at any time, independent of meals", in the abdomen, thigh or upper arm, and that it is preferable to inject it around the same time each day. Wegovy is injected once a week, at any time of day, with or without meals, in the same body areas.

Pens and strengths

Saxenda has a single pen strength. Each pen holds 18 mg of liraglutide in 3 ml and, in the SmPC's words, "is able to deliver doses of 0.6 mg, 1.2 mg, 1.8 mg, 2.4 mg and 3.0 mg".

Each Wegovy FlexTouch pen is made in one strength and holds 4 weekly doses, at 0.25 mg, 0.5 mg, 1 mg, 1.7 mg or 2.4 mg. The 7.2 mg strength, for weight management in adults with obesity, is a single-dose pen. The two substances are measured on different scales, and the prescriber decides the medicine and the strength.

Needles and packs

The Saxenda SmPC lists packs of 1, 3 or 5 pens and states: "Needles are not included." It says the pen is designed for NovoFine or NovoTwist needles up to 8 mm long. Each Wegovy FlexTouch pack contains one pen and 4 NovoFine Plus needles, and the 7.2 mg pens come 4 to a pack with the needle attached.

What each UK licence covers

The adult weight management indications use the same BMI wording: an initial BMI of 30 kg/m² or more, or of 27 to under 30 kg/m² with at least one weight-related comorbidity, alongside a reduced-calorie diet and increased physical activity. Both licences also cover adolescents aged 12 and over with obesity and a body weight above 60 kg, and each SmPC defines obesity in adolescents by its own growth chart cut-offs.

Wegovy's licence also covers reducing the risk of major adverse cardiovascular events in adults with established cardiovascular disease and a BMI of 27 kg/m² or more, and treating MASH, a form of liver disease, with moderate to advanced liver fibrosis. Saxenda's licence has neither of these uses.

NICE and the NHS

NICE technology appraisal TA664, published in December 2020, recommends liraglutide for adults with a BMI of at least 35 kg/m² (32.5 kg/m² for some minority ethnic groups), non-diabetic hyperglycaemia and a high risk of cardiovascular disease, prescribed in secondary care by a specialist multidisciplinary tier 3 weight management service.

TA875 recommends semaglutide within a specialist weight management service for a maximum of 2 years, for adults with at least one weight-related comorbidity and a BMI of at least 35.0 kg/m², or of 30.0 to 34.9 kg/m² when they meet the criteria for referral to a specialist service.