How does Wegovy’s impact on blood sugar levels compare to Ozempic?

Both contain semaglutide and improve blood sugar by enhancing insulin release and reducing glucagon. Ozempic is specifically licensed for diabetes at lower doses, while Wegovy provides the same benefits at higher doses alongside more pronounced weight reduction.

How semaglutide works on blood sugar

Semaglutide, the active ingredient in both Wegovy and Ozempic, belongs to the GLP-1 receptor agonist family. It lowers blood sugar by stimulating insulin release when glucose levels rise and by reducing glucagon, a hormone that raises blood sugar. It also slows gastric emptying, which helps prevent sharp spikes in glucose after meals. These mechanisms explain why semaglutide is effective not just for weight control but also for managing type 2 diabetes.

Wegovy: higher dose, broader goals

Wegovy (semaglutide 2.4 mg weekly) is licensed in the UK for weight management rather than diabetes. In the STEP-2 trial, which focused on adults with both obesity and type 2 diabetes, participants taking Wegovy lost nearly 10% of their body weight and saw significant improvements in HbA1c (a long-term blood sugar marker). These results highlight that Wegovy improves glucose control while also delivering stronger weight reduction than lower-dose semaglutide.

Ozempic: targeted diabetes care

Ozempic (semaglutide up to 1 mg weekly, with 2 mg available in some settings) is licensed specifically for type 2 diabetes. In the SUSTAIN trials, it lowered HbA1c by about 1.5–1.8 percentage points on average, alongside modest weight loss of around 5–7% of body weight. Its primary role is to help people reach blood sugar targets, with weight loss treated as a secondary benefit.

Comparing the outcomes

The key difference is scale. Both Wegovy and Ozempic improve blood sugar through the same mechanism, but Wegovy’s higher dose leads to stronger effects on weight. Weight reduction itself contributes to better glucose control, which means people on Wegovy often see additional benefits compared to those on Ozempic. However, Ozempic remains highly effective for diabetes management and is preferred when the primary goal is glucose control rather than weight loss.

NHS guidance

NICE guidance makes the distinction clear. Ozempic is recommended for people with type 2 diabetes who need better glucose control after first-line therapies. Wegovy is recommended for adults with obesity who meet BMI criteria within specialist weight-management services, regardless of whether they also have diabetes. This separation ensures that the right medicine is used for the right clinical purpose.

Side effects and tolerability

Since both contain semaglutide, side effects are similar: nausea, diarrhoea, and constipation are most common. Some people report stronger digestive effects on Wegovy, likely because of the higher dose, but gradual titration helps manage this. Safety monitoring applies equally to both medicines, particularly in people with existing gastrointestinal conditions or other risk factors.

What the evidence shows overall

Both Wegovy and Ozempic improve blood sugar, but their uses differ. Ozempic is the established diabetes treatment, effective at lower doses. Wegovy, at a higher dose, offers the same blood sugar benefits while producing greater weight loss, which in turn enhances glucose control. The choice between them depends on whether the main goal is treating diabetes, managing weight, or both together.