Wegovy (semaglutide) in the treatment of obesity

What is Wegovy?

Wegovy contains the active substance semaglutide and is approved for the treatment of obesity. It is used to help adults with a body mass index (BMI) of 30 or higher, or those with a BMI of 27 and above who also have other weight-related health conditions, such as high blood pressure or type 2 diabetes. Wegovy works as a complement to changes in diet and physical activity and is designed to support sustainable weight loss by influencing the body’s appetite and satiety signals (1).

How does Wegovy work?

Semaglutide is a GLP-1 receptor agonist that mimics the natural hormone GLP-1 (glucagon-like peptide-1). GLP-1 is normally released from the small intestine after eating and plays several important roles in regulating appetite, satiety and blood glucose levels (2).

By enhancing these natural processes, Wegovy provides several beneficial effects:

• Reduced appetite and increased satiety: The medicine affects the appetite centre in the brain, helping you feel full more quickly and for longer. This can reduce energy intake and support weight loss.
• Slower gastric emptying: Semaglutide delays the emptying of the stomach, helping to stabilise blood glucose levels after meals and enhancing satiety.
• Improved blood glucose control: The treatment stimulates insulin release when blood glucose levels are elevated and suppresses glucagon production, helping to maintain more stable glucose levels.

Together, these mechanisms contribute to sustainable weight loss and improved metabolic health.

Clinical effectiveness

Semaglutide, the active ingredient in Wegovy, has demonstrated significant and clinically relevant effects on body weight in people with overweight or obesity.

In the large STEP programme (Semaglutide Treatment Effect in People with obesity), where participants received 2.4 mg semaglutide once weekly combined with lifestyle support, an average weight loss of around 15–17% of body weight was achieved after 68 weeks, compared with around 2–3% in the placebo group (2). These results show that semaglutide 2.4 mg is one of the most effective medication-based options for weight management in obesity when combined with lifestyle changes.

Who can be treated with Wegovy?

Wegovy is indicated for weight management in adults with a BMI of at least 30, which corresponds to obesity. It may also be used by individuals with a BMI of 27 or above who have additional weight-related health conditions such as high blood pressure, type 2 diabetes or other risk factors that increase the likelihood of complications (3).

People who have previously tried to lose weight through diet and physical activity without success may benefit greatly from treatment with Wegovy.

How Wegovy is used for weight loss

Wegovy is taken as an injection once weekly or as prescribed by a doctor. The injection is given into the subcutaneous fat of the abdomen, thigh or upper arm using a pre-filled injection pen. After the injection, the body absorbs semaglutide gradually, influencing appetite regulation and reducing hunger, which contributes to weight loss (3).

Treatment should be used according to medical instructions and taken regularly to achieve the best possible effect, usually once a week. The starting dose is typically 0.25 mg. The dose may then be increased gradually depending on how the body responds and the doctor’s recommendations. This gradual increase helps the body adapt and reduces the risk of side effects.

It is not always necessary to reach the highest dose; treatment continues at the dose that provides a good effect. It is important to use the medicine continuously and not stop too early, as the weight-loss effect can decline quickly if treatment is discontinued.

Treatment should always be carried out with medical supervision and as part of a long-term weight-management programme. It is also important for patients to understand that Wegovy is not a miracle cure; it must be used alongside lifestyle changes (3).

Lifestyle changes for weight loss

For Wegovy to deliver the best possible results, a comprehensive approach is needed. This means that the medication should be combined with healthy changes such as nutritional adjustments, regular physical activity, stress management and good sleep habits — ideally with support from healthcare professionals.

Diet for healthy weight loss with Wegovy

To lose weight, a calorie deficit is required, meaning you consume less energy than you spend. Medication can make this easier by increasing feelings of fullness and reducing hunger, which is common when restricting calories.

When energy intake is reduced, it becomes even more important that the diet is nutrient-dense and meets the body’s needs for vitamins, minerals and protein. Adequate protein intake helps promote satiety, maintain muscle mass during weight loss and improve body composition, especially when combined with strength training (3).

Dietary guidance should always be tailored to the patient’s current eating habits, preferences and circumstances.

Physical activity and training

Physical activity is a key part of a comprehensive weight-loss treatment. It can enhance the effect of medication, improve overall wellbeing and help prevent or manage side effects. Exercise helps preserve muscle mass, increase metabolism and support mental health. Regular movement can also reduce stress, improve sleep and decrease the risk of obesity-related diseases (3).

Recommended types of activity include:

• Everyday movement: taking the stairs, walking, cycling or standing more often everyday.
• Cardiovascular activity: brisk walking, swimming or cycling.
• Strength training: 2–3 times per week, especially important for maintaining muscle mass and supporting a healthy body composition (4).

Activity plans should always be adapted to the individual's abilities, health status and goals.

The importance of sleep

Adequate sleep is crucial for healthy weight regulation. Lack of sleep affects hormonal systems that regulate appetite, satiety and energy balance (5).

Stress can affect weight loss

Long-term stress can lead to elevated cortisol levels, which affect both appetite regulation and metabolism. What is perceived as stressful is individual and influenced by personality, life situation and past experiences. Support and treatment therefore need to be personalised. For some, this may mean reducing external stressors; for others, building resilience and developing strategies to manage stress. Regular movement, sufficient sleep and stress-reducing techniques can be valuable components (6).

Common side effects

The most common side effects of semaglutide are gastrointestinal. They are usually mild to moderate and tend to diminish after the initial period of treatment.

Common side effects of Wegovy include:

• Nausea
• Diarrhoea
• Vomiting
• Constipation
• Gas or bloating

Nausea is the most common side effect and mainly occurs during the first weeks when the dose is gradually increased. For many people, symptoms lessen once the body adapts to the treatment (1,3).

How to reduce gastrointestinal discomfort

To ease symptoms, patients may:

• eat smaller portions
• eat slowly and stop when feeling full
• avoid fatty, spicy or fried foods
• drink water frequently but in small amounts
• avoid carbonated drinks
• engage in regular physical activity

If symptoms persist or significantly affect daily life, patients should contact healthcare services for assessment, advice and support (3).

Other side effects

Wegovy may also cause an increase in heart rate. The risk of hypoglycaemia increases mainly when used with insulin or sulfonylureas; dose adjustments of these may be needed. Rare but serious side effects include pancreatitis or gallstone disease. Patients should contact their doctor if severe or persistent symptoms occur.

Important considerations when using Wegovy

It is important to use Wegovy as part of a long-term treatment plan. Stopping the medication too early may increase the risk of regaining weight. Treatment should continue for as long as the doctor considers it beneficial.

Patients should also be informed that Wegovy is not suitable, or should be used with caution, in certain situations — for example in people with type 1 diabetes, certain thyroid conditions or a history of pancreatitis. It is also not prescribed to pregnant or breastfeeding women or to those planning pregnancy within the next two months. A careful medical assessment is therefore essential before starting treatment (1).

Patients should read more about possible risks and contraindications before beginning treatment with Wegovy.

Summary – Wegovy

Wegovy is a medicine that can support weight loss in patients with overweight or obesity. The active ingredient semaglutide affects the body’s hunger and satiety signals, helping to achieve effective and sustainable weight loss.

The medicine is administered as a weekly injection according to medical instructions and is prescribed together with lifestyle changes such as diet and physical activity for the best results. For many, Wegovy not only improves weight management but also reduces the risk of complications and supports better long-term health.

It is essential that treatment is carried out under medical supervision and that patients make the lifestyle changes needed to maintain their weight and health over time.

References

1. European Medicines Agency: Wegovy – European Public Assessment Report (EPAR) (European Medicines Agency): https://www.ema.europa.eu/en/medicines/human/EPAR/wegovy
2. Bergmann, N. C., Davies, M. J., Lingvay, I., & Knop, F. K. (2023). Semaglutide for the treatment of overweight and obesity: A review. Diabetes, Obesity and Metabolism, 25(1), 18–35. https://doi.org/10.1111/dom.14863
3. Konstantinos C Koskinas, Emeline M Van Craenenbroeck, Charalambos Antoniades, Matthias Blüher, Thomas M Gorter, Henner Hanssen, Nikolaus Marx, Theresa A McDonagh, Geltrude Mingrone, Annika Rosengren, Eva B Prescott, the ESC Scientific Document Group. Obesity and cardiovascular disease: an ESC clinical consensus statement. European Heart Journal. 2024;45(38):4063–4098. https://doi.org/10.1093/eurheartj/ehae508
4. World Health Organization (WHO). WHO Guidelines on Physical Activity and Sedentary Behaviour. Geneva: World Health Organization; 2020. Available at: https://www.who.int/publications/i/item/9789240015128
5. Chaput JP, McHill AW, Cox RC, Broussard JL, Dutil C, da Costa BGG, Sampasa-Kanyinga H, Wright KP Jr. The role of insufficient sleep and circadian misalignment in obesity. Nat Rev Endocrinol. 2023 Feb;19(2):82-97. doi: 10.1038/s41574-022-00747-7. Epub 2022 Oct 24. PMID: 36280789; PMCID: PMC9590398.
6. Lengton R, Schoenmakers M, Penninx BWJH, Boon MR, van Rossum EFC. Glucocorticoids and HPA axis regulation in the stress-obesity connection: A comprehensive overview of biological, physiological and behavioural dimensions. 2025. Available at: https://pubmed.ncbi.nlm.nih.gov/39623561/

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