Wegovy: what to know about the weight-loss injection

What is Wegovy?

Wegovy is the brand name for a medicine called semaglutide. It is approved for use in the NHS, alongside diet and physical activity, to manage excess weight and obesity in some people. 

It is only available through specialist weight management clinics. Your GP can refer you to a clinic to see if Wegovy could be suitable for you. 

Wegovy comes as a pre-filled injector pen. You can use it to inject yourself weekly, under the skin in the upper arms, stomach, thighs or buttocks.  

Wegovy is 1 of 3 weight-loss injections available on the NHS, the others being Saxenda (liraglutide) and Mounjaro (tirzepatide). 

In July 2024, Wegovy was also approved to help lower the risk of heart attack and stroke in people diagnosed with heart and circulatory diseases, who also have a Body Mass Index (BMI) classed as overweight or obese (higher or equal to 27). 

It’s the first obesity drug doctors are allowed to prescribe specifically to reduce the risk of heart and circulatory disease in people living with excess weight or obesity, according to the UK Medicines and Healthcare products Regulatory Agency (MHRA).

However, there are no details yet as to which NHS doctors and/or clinics will be able to offer it to patients. 

How does it work?

Wegovy acts on areas of the brain which are involved in regulating your appetite. It increases feelings of fullness, reduces feelings of hunger and reduces the preference for high-fat foods.

It also reduces blood sugar by promoting the release of insulin when blood sugar levels are high. Another name for semaglutide is Ozempic, which is used to treat type 2 diabetes because it can reduce blood sugar.

Can I get treated with Wegovy on the NHS?

You can be treated with Wegovy in a specialist weight management service if you have:

• a weight-related health condition, including high blood pressure, high cholesterol or cardiovascular disease
• obesity, classed as a BMI of 35 or more
• tried to lose weight through conventional treatment, which hasn’t worked.

You may also be prescribed Wegovy if you have a BMI of 30 to 34.9 and have been referred to a specialist weight management clinic.

If you're from an Asian, Chinese, Middle Eastern, Black African or African-Caribbean background you may qualify for Wegovy with a lower BMI.

• Read the guidance for prescribing Wegovy.

How effective is it?

A study on Wegovy published in 2021, funded by the drug’s makers Novo Nordisk, looked at whether adults with obesity can achieve weight loss with one-weekly semaglutide.

The study showed that when Wegovy was used for 15 months with lifestyle support from a professional to follow a calorie-reduced diet and to get more active, people lost on average 15% of their body weight.

This compares to people in the study who had the same lifestyle support but dummy (placebo) injections, who only lost 2.4% of their body weight on average.

The study in the New England Journal of Medicine also found that taking the drug can lead to a smaller waistline and lower blood pressure.

Research published in the same journal in 2023 was used to support the MHRA’s approval of Wegovy for lowering the risk of heart attack and stroke in people with heart disease and overweight or obesity.

The trial included 17,604 people who received either weekly Wegovy or dummy injections (placebo) for up to 5 years. 

The study found those taking Wegovy had a 20% lower risk of death from heart and circulatory disease, heart attack or stroke, compared to those taking placebo. 

Just 6.5% of participants in the Wegovy group experienced a heart event versus 8% in the placebo group. 

Do I still need to diet and exercise?

Yes, it’s important to also make changes to your diet to reduce the amount of calories you are eating and to take part in regular exercise.

This will help you to get the most out of taking this medication and to help you to avoid gaining weight when you stop taking this medicine. Your specialist clinic should be able to support you with this. 

Are there any side effects or long-term risks?

As with all drugs, Wegovy can cause side effects. The most common are feeling or being sick, or diarrhoea.

Rarer, but more serious, problems include gall bladder disease, inflammation of the pancreas and kidney issues.

Treatment with Wegovy is limited to 2 years and its long-term risks are still being studied. 

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