Semaglutide for weight loss – information about the medicine

What is semaglutide?

Semaglutide is a synthetic medication that mimics a hormone found naturally in the body that regulates blood sugar and appetite. There are several variants of semaglutide, including Ozempic and Rybelsus for diabetes, and Wegovy for weight loss. They contain the same active substance but in different doses and forms of administration.

How does semaglutide 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 a meal and has several key functions in the regulation of appetite, satiety and blood sugar.

By enhancing these natural processes, semaglutide contributes to several beneficial effects:

• Reduced appetite and increased satiety: The medication affects the appetite centre in the brain, causing satiety to be reached more quickly and to last longer. This leads to reduced energy intake and supports weight loss.
• Slower gastric emptying:Semaglutide delays the emptying of the stomach, which stabilises post-meal blood glucose levels and reinforces the feeling of fullness.
• Improved blood sugar control:The treatment stimulates insulin release when blood sugar levels are elevated and suppresses glucagon production, contributing to more stable glucose levels.

Together, these mechanisms support sustained weight loss and improved metabolic health, making semaglutide an effective treatment option for overweight and obesity (1).

Clinical effectiveness

In the extensive 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 reduction of around 15–17% of body weight was achieved after 68 weeks of treatment, compared with around 2–3% in the placebo group (1).

How the treatment works

Treatment begins with a medical assessment where BMI and general health are evaluated. During the assessment, the patient answers questions about their health and lifestyle.

Wegovy is indicated for weight management in individuals with a BMI (body mass index) of at least 30, which corresponds to obesity. The medication can also be used by individuals with a BMI of 27 and above who have other weight-related health issues, such as high blood pressure, type 2 diabetes or other risk factors that increase the risk of associated diseases (2).
People who have previously tried to lose weight through diet and physical activity without success may greatly benefit from semaglutide treatment.

How semaglutide is used for weight loss

Wegovy is taken as an injection once weekly or as prescribed by a doctor. The injection is administered into the subcutaneous fat of the abdomen, thigh or upper arm using a pre-filled injection pen. After injection, the body absorbs semaglutide gradually, affecting appetite regulation and reducing hunger, thereby supporting weight loss.

Semaglutide should be used according to medical instructions and taken regularly to provide the best possible effect, typically once per week. The initial dose is usually 0.25 mg. The dose may then be gradually increased depending on how the body responds and on the doctor’s recommendations. This gradual increase allows the body to adjust and reduces the risk of potential side effects.

The dose is individualised and increased only to the level that provides the desired effect and is well tolerated. It is important to use the medication continuously and not discontinue it prematurely, as the effects on weight may diminish quickly if treatment is stopped.

The treatment should always take place under medical supervision and as part of a long-term weight management programme. Semaglutide is not a quick fix, but part of a long-term, structured treatment strategy and should be used alongside lifestyle changes (3).

Lifestyle changes in connection with semaglutide

For semaglutide to provide the best possible results for weight loss, a comprehensive strategy is required. This means that the medication should be combined with healthy changes such as improved eating habits, regular physical activity, stress management and good sleep – ideally with support from healthcare professionals.

Diet for healthy weight

To lose weight, a calorie deficit is needed, meaning that energy intake is lower than energy expenditure. Medication can make this easier by increasing satiety and reducing the hunger that often arises during calorie restriction.

When energy intake decreases, it is particularly important that the diet is nutrient-dense to meet the body’s needs for vitamins, minerals and protein. An optimal protein intake contributes to better satiety, preserved muscle mass during weight loss and improved body composition – especially when combined with strength training (3).

Treatment should always be individually tailored. Start from the patient’s current eating habits, preferences and circumstances, and make adjustments accordingly.

Physical activity and exercise

Physical activity is an important part of comprehensive weight-loss treatment. It can enhance the effectiveness of the medication and improve overall wellbeing, as well as prevent and reduce side effects. Activity helps preserve muscle mass, improve metabolism and increase psychological wellbeing. Regular movement can also reduce stress, improve sleep and lower the risk of associated diseases.

It is recommended to combine different types of physical activity (4):

• Everyday movement: taking the stairs, walking, cycling or standing more often
• Cardiovascular activities: such as brisk walking, swimming or cycling
• Strength training 2–3 times per week: particularly important for preserving muscle mass and promoting healthy body composition

Regular physical activity is a central part of treatment, but recommendations should always be adapted to the individual’s abilities, limitations, health status and goals.

The importance of sleep

Sufficient and regular sleep is a central part of healthy weight regulation. Inadequate sleep affects several hormonal systems that regulate appetite, satiety and energy balance, which can increase hunger and lead to a higher intake of calorie-dense foods (5).

Prioritising good sleep quality not only supports effective and sustainable weight loss, but also contributes to better recovery after physical activity, improved cognitive function and enhanced mental wellbeing. These factors are essential for maintaining healthy lifestyle habits long term and preventing weight regain.

Stress

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. Therefore, support and treatment need to be tailored to each person’s needs.

For some, this means reducing external stressors; for others, it means strengthening their capacity for recovery and developing strategies to handle strain. Regular movement, sufficient sleep and stress-reducing techniques can all be valuable parts of this process (6).

Common side effects

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

The most common side effects when using semaglutide are:

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

Nausea is the most frequent side effect and occurs mainly during the first weeks as the dose is gradually increased. For many people, these symptoms lessen once the body has adapted to the treatment (1, 3).

How to relieve stomach discomfort

To relieve symptoms, the patient can:

• Eat smaller portions
• Eat slowly and stop when feeling full
• Avoid fatty, heavily seasoned or fried foods
• Drink water frequently, but in small amounts at a time
• Avoid carbonated drinks
• Engage in regular physical activity

If symptoms do not improve or significantly affect daily life, the patient should contact healthcare services for assessment, advice and support.

Other side effects

As GLP-1 receptors are present in the heart, an increase in heart rate may occur during treatment with semaglutide. The risk of hypoglycaemia increases mainly when combined with insulin or sulfonylureas; dose adjustments of these may be necessary. In rare cases, pancreatitis or gallstone disease may occur. It is important that the patient contacts a doctor if severe or long-lasting symptoms develop.

Important considerations when using semaglutide

It is important to use semaglutide as part of a long-term treatment plan. Stopping the medication too early may increase the risk of regaining weight. Therefore, treatment is recommended for as long as the doctor considers there to be benefit.

Patients should also be informed that semaglutide is not suitable in certain situations or should be used with caution — for example, in people with type 1 diabetes, a history of pancreatitis, or certain other underlying conditions or diseases. The medication is also not given to pregnant or breastfeeding individuals, or to those planning a pregnancy within the next two months. For this reason, a thorough medical assessment is essential before treatment is initiated.
Patients should read about potential risks and contraindications before starting therapy with semaglutide.

Long-term weight management

Achieving and maintaining a healthy weight in the long term requires changes that are sustainable over time. This means focusing on making small, long-lasting improvements in diet, engaging in regular physical activity, and seeking support when needed. It is important to set realistic goals and not give up when challenges arise — weight loss is a journey where every step counts.

By eating healthily, staying active and taking care of one’s health, lasting weight loss and improved quality of life can be achieved.

Summary

Semaglutide-based medications are effective for medical weight loss and should be combined with lifestyle changes. They are not a quick fix, but require commitment and medical follow-up to achieve long-term results. When used correctly, they can provide significant, sustainable weight reduction and improved health.

References

1. 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
2. European Medicines Agency (EMA): Wegovy – EPAR (översikt och godkännande)
   https://www.ema.europa.eu/en/medicines/human/EPAR/wegovy
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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