The Independent Pharmacy

How Does Wegovy Work For Weight Loss

Daniel Hurley
Daniel HurleyMPharm IPPharmacist Independent Prescriber

Reviewed on 2 Apr 2024

Wegovy is a new prescription drug that helps patients lose excess weight. It works by mimicking a gut hormone called glucagon-like peptide-1 (GLP-1) that targets areas of the brain involved in appetite regulation. We understand that the weight loss journey can be incredibly challenging. Wegovy aims to make it a bit easier by helping you feel full sooner so you eat less.

This article will explain the science behind Wegovy’s mechanism of action in simple terms. You’ll learn how it curbs appetite, its effectiveness compared to other weight management interventions, and answers to questions we often hear from people like you.

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As you continue reading, you’ll uncover how this injectable formula impacts the brain to suppress appetite through its active ingredient, semaglutide. You’ll also find clinical trial results demonstrating Wegovy’s ability to facilitate significant weight loss in adults with obesity. Additionally, you’ll discover how Wegovy compares to other medications and lifestyle changes for losing weight.

Key Takeaways:

  • Wegovy is a new prescription medication injected weekly for weight loss.
  • It works similarly to a hormone called GLP-1 that signals fullness and suppresses appetite.
  • In clinical studies, people taking Wegovy experienced significant body weight loss, with an average of 5-15% or more of their starting weight.
  • Weekly Wegovy injections decrease appetite and food intake to facilitate weight loss.

What Is Wegovy?

Wegovy is a prescription injectable weight loss drug approved in 2021 by the U.S. Food and Drug Administration (FDA) and the UK Medicines and Health Products Regulations Agency (MHRA) for chronic weight management. However, injectable prescription medicine has become available in the UK only very recently, in September 2023. If you’re living with obesity and facing additional weight-related health conditions like diabetes or high blood pressure, know that you’re not alone. Wegovy is specifically designed to help people in situations like yours.

Wegovy belongs to a class of medications called GLP-1 receptor agonists. It works similar to a natural hormone called glucagon-like peptide-1 (GLP-1). Our bodies make GLP-1 in the intestines, and it sends signals to the brain to control appetite and feelings of fullness after eating.

The active ingredient in Wegovy is semaglutide. Semaglutide is a man-made version of GLP-1 and can help lower blood sugar levels. It activates receptors in areas of the brain involved in food intake and appetite signalling. This makes you feel fuller faster, eat less, and lose weight.

In the 68-week clinical trial, Wegovy patients lost an average of 17% of their body weight, compared to just 2.4% for patients getting placebo injections without semaglutide. About 67% of Wegovy patients lost at least 10% of their initial weight. This also means that there has been a significant reduction in their initial body mass index.

We know that dealing with side effects like nausea and stomach pain can be distressing. While these are common and usually temporary, it’s important to consult your healthcare provider for guidance. Wegovy also has some risks, like thyroid cancer, that doctors monitor for.

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How Does Wegovy Work?

Wegovy works similar to a hormone called glucagon-like peptide-1, or GLP-1 agonists. Our bodies naturally produce GLP-1 in the gut. This hormone sends signals to the brain that control appetite and make you feel full after eating.

The active drug in Wegovy is semaglutide. Semaglutide mimics the effects of GLP-1. It activates receptors for GLP-1 that are found in several areas of the brain involved in food intake and appetite control.

When semaglutide in Wegovy activates these receptors, it decreases appetite signals and increases feelings of fullness. People feel satisfied with less food and naturally reduce their calorie intake.

Wegovy also appears to slightly increase the number of calories burned at rest. So, it not only lowers calorie intake through appetite suppression but may also raise daily energy expenditure.

In studies, people who took Wegovy lost more weight than people who did not take it. On average, Wegovy patients lost 5-15% or more of their starting body weight by reducing appetite and calories consumed.

The way semaglutide interacts with key parts of the brain to influence appetite and metabolism is central to how Wegovy facilitates weight loss.

How to Use Wegovy

Wegovy is administered through a once-weekly injection under the skin, known medically as a subcutaneous injection. Patients start at a low dose of 0.25 milligrams (mg) to allow their body to adjust to the medication. The dose is gradually increased over 16 to 20 weeks until reaching the full maintenance dose of 2.4 mg. Slowly ramping up the dosage helps minimise common side effects like nausea, vomiting, and diarrhoea, or even some of the rare, more serious side effects like increased heart rate or serious allergic reactions.

Patients can inject Wegovy themselves at home after receiving proper training and medical advice from a healthcare professional. Common injection sites include the abdomen, thighs, or back of the upper arm. These areas have more fatty tissue which makes injections easier. The injection should not be given into areas where the skin has blemishes, bruising, redness, or hardness. Proper injection technique is important to ensure the medication is delivered effectively.

Certain patients should not use Wegovy, including:

  • Those with a personal or family medical history of medullary thyroid carcinoma, a type of thyroid tumour
  • Patients with Multiple Endocrine Neoplasia syndrome type 2, a condition causing thyroid and other endocrine tumours
  • People with severe inflammatory bowel disease, chronic pancreatitis, or other severe gastrointestinal problems

Effectiveness of Wegovy

Multiple clinical trials have demonstrated Wegovy’s efficacy for weight loss in adults. In a 68-week study of nearly 2,000 overweight or obese adults, people taking Wegovy had an average weight loss of 17% compared to 2.4% for the placebo group.

Additionally, over two-thirds of Wegovy patients lost at least 10% of their initial body weight, compared to only 12% of placebo patients. Greater weight loss was observed with higher Wegovy doses up to 2.4 mg.

Other studies showed Wegovy patients lost 15-18% of initial body weight on average, with some losing up to 25%. The amount of weight loss plateaued around one year during continued treatment. These results show that Wegovy consistently promotes significant weight loss when used long-term.

Wegovy is one of the most effective weight loss medications approved for chronic use based on clinical evidence. We recognise that everyone’s journey is unique, and results can vary. Your healthcare provider can help tailor a plan that works best for you.

Comparing Wegovy to Other Weight Loss Solutions

If you’ve tried diet and exercise without the results you’ve hoped for, it can be disheartening. Wegovy offers a different approach that could make a meaningful difference. Lifestyle changes alone produce an average weight loss of 5-10%, while Wegovy patients lost up to 25% of body weight in clinical trials.

However, Wegovy works best with lifestyle modifications. Following a reduced-calorie meal plan and increasing physical activity while taking Wegovy can amplify weight loss, especially initially. But diet and exercise alone cannot match Wegovy’s ability to consistently deliver significant, maintained results.

Compared to other weight loss medications, Wegovy produces greater average weight loss based on clinical trials. For example, the diabetes medication liraglutide leads to around 5-10% weight reduction. Naltrexone/bupropion, another obesity drug, reduces weight by about 5% on average. Wegovy’s impact exceeds these other pharmacological treatments.

In summary, no other non-surgical obesity intervention rivals Wegovy in terms of the magnitude and durability of weight loss seen in studies. It represents an exciting new treatment for people with chronic weight management issues when combined with lifestyle changes.

People Also Ask

Many patients have questions about what to expect when taking Wegovy. Here are answers to some of the most frequently asked questions about this weight loss medication:

How much weight can you lose in a month with Wegovy?

In clinical trials, patients lost an average of 5-10% of their body weight over 3 months on Wegovy. However, long-term weight loss varies between individuals based on factors like medication dosage, diet, and activity levels. Some may lose up to 2 pounds per week or 8 pounds in a month.

How long does it take for Wegovy to start working?

Most patients notice reduced appetite and increased feelings of fullness within a few days or weeks of starting Wegovy. However, the scale may not show significant weight loss for several weeks as stored body fat starts to be metabolised. Maximum weight loss effects are seen around 20 weeks as dosage increases.

How quickly do you see weight loss with Wegovy?

People typically experience the most rapid weight loss in the first 3-6 months of Wegovy treatment. Weight continues decreasing more gradually after about month 6 during ongoing maintenance therapy. Total weight loss builds up over months of use.

What is the best diet while on Wegovy?

Experts recommend a reduced-calorie meal plan focused on whole, minimally processed foods like fruits, vegetables, lean proteins, whole grains, and healthy fats. Portion control is important. Low-calorie diets amplify Wegovy’s effects. Once you reach a healthy weight, it’s important to maintain it to prevent future weight gain.


In summary, Wegovy is an exciting new prescription medication for chronic weight management. It promotes weight loss by mimicking GLP-1, a hormone that targets appetite and food intake control centres in the brain.

The active ingredient semaglutide in Wegovy activates GLP-1 receptors to suppress appetite and enhance feelings of fullness. This leads to reduced calorie consumption and significant weight reduction.

Clinical trials demonstrate Wegovy’s ability to facilitate the loss of up to 25% of body weight when used long-term, along with lifestyle modifications. It represents one of the biggest advances in pharmacological obesity treatment to date.

We understand that there’s no quick fix for weight loss, and the journey can be long and difficult. Wegovy offers a new path that, under medical supervision, could be the change you’ve been hoping for. Sustained weight loss is possible when combining this medication with dietary changes, increased activity, and ongoing patient-healthcare provider collaboration.

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