How Does Wegovy (Semaglutide) Work?

Wegovy is the brand name for the weight loss medicine called semaglutide. Wegovy acts on the parts of the brain that tell you you’re hungry. It reduces your appetite and slows digestion to help you lose weight.

Obesity is the second most common cause of avoidable cancer. Every year, the NHS spends around £6.5 billion per year on obesity. With more than 25% of adults in the UK classed as obese, greater support is needed to help these individuals lose weight.

Prescription medicines, particularly weight loss injections are an effective and safe solution for the most severe cases. Medicines like Wegovy can support individuals to lose weight for better health and an improved quality of life.

With research showing that Wegovy users can lose up to 15% of their body weight in a year, we explore how Wegovy works for weight loss.

What is Wegovy used for?

Wegovy is prescribed to people who are obese and have found it difficult to lose weight with diet and exercise alone. It can also be used by people who are overweight and have underlying health conditions, such as high blood pressure or high cholesterol which can make weight loss difficult.

Wegovy has been recommended for weight loss in the UK by the National Institute for Health and Care Excellence (NICE).

How does Wegovy work?

Wegovy contains the active ingredient semaglutide which mimics a hormone naturally produced in the gut during digestion called glucagon-like peptide-1 (GLP-1).

Wegovy helps in weight loss by reducing appetite meaning you eat less food and lose weight. It also slows down how quickly your stomach empties which helps to keep you feeling satisfied for longer, so you’re less likely to eat another meal in close succession.

Semaglutide also helps to regulate blood sugar levels by increasing the amount of insulin produced by the pancreas and lowering the amount of glucose (sugar) made in your liver.

How does Wegovy aid weight loss?

Wegovy is a GLP-1 receptor agonist which works in the same way as the naturally occurring hormone GLP-1. To aid weight loss, it acts on the parts of the brain responsible for controlling your appetite, so it makes you feel full after you have eaten, so you feel less hungry. It also controls your blood sugar levels by stimulating insulin release when blood glucose levels are high. Wegovy weight loss injections also lower the amount of fat produced.

How much weight will I lose while using Wegovy for weight loss?

On average people using Wegovy achieved a 15% body weight loss compared to 2.4% in people given a placebo over 68 weeks on the STEP-1 clinical trial.

The study also showed that when combined with a diet and exercise plan, the participants assigned to Wegovy (semaglutide) injections lost more weight than those given a placebo.

These figures are average figures and everyone will be different. The body weight you will lose will depend on your situation and may also fluctuate according to the prescribed Wegovy dose.

Is Wegovy suitable for me?

To receive a Wegovy prescription you will need to meet certain criteria. It will only be prescribed to people who have a BMI of at least 30 or 27 and have a weight-related health condition like high blood pressure.

If you meet the criteria, it’s likely Wegovy will be prescribed if other weight loss attempts have not been successful or if you are struggling to lose weight with diet and exercise alone.

Will Wegovy help me lose weight?

Wegovy is a safe and effective weight loss treatment for most people, but it may not be suitable for everyone. Wegovy’s manufacturer claims that 83% of people have lost at least 5% of their body weight while using the injections. That means that it potentially isn’t suitable or successful for 17% of people. If Wegovy doesn’t help you lose weight, you may need to explore other options.

How long does Wegovy take to work for weight loss?

Wegovy gets to work quickly to help you lose weight. Clinical trials show that weight loss can occur within the first 4 weeks of starting Wegovy, with an average of around 2% body weight loss.

If you haven’t lost significant weight after 6 months of using Wegovy, you should discuss other weight loss options with your clinician.

How long does Wegovy stay in your body?

At its maximum dose of 2.4 mg, semaglutide, the active ingredient in Wegovy, takes approximately 7 weeks to clear the body after your last dose.

Which is better, Wegovy or Mounjaro?

Mounjaro is another example of a weight loss injection which contains the active ingredient tirzepatide. Some research shows that Mounjaro is more effective for weight loss than semaglutide.

Mounjaro works similarly to Wegovy except it mimics two digestive hormones, GLP-1 and gastric inhibitory polypeptide (GIP) to suppress appetite, delay the time it takes for food to be digested, and increase insulin secretion in response to high blood sugar levels. Our page ‘Mounjaro vs Wegovy: A Comprehensive Comparison’ provides an in-depth analysis of the two weight loss injections.

Summary

Wegovy works by targeting the areas of the brain responsible for managing your appetite. It mimics the digestive hormone GLP-1 and helps to signal that you are full and slows down the digestive process, to help reduce your food intake and initiate weight loss.

Wegovy is effective in more than 80% of people, but if it doesn’t work for you, there are other weight loss options available.

Authored & Reviewed By

Mohamed Imran Lakhi

MPharm - Lead Pharmacist

Imran Lakhi is the superintendent pharmacist and founder at Prescription Doctor. He has been at the core of our team.

Published on: 14/09/2023 Reviewed on: 01/11/2023